DENTAL ANATOMY

Course Manuals

LECTURE 6540 and LABORATORY 6543

Charles J. Arcoria, D.D.S., M.B.A. Course Director

Burt Bryan, D.D.S. Course Co-Director

Fall 2011

Department of Restorative Sciences

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Acknowledgments

Past Contributors

Dr. Paul E. Krupp Dr. Damon W. Spencer

Dr. Frederick A. Shaw III Dr. Everett Payne

Dr. Robert S. Staffanou Dr. C. Larry Cloetta

Dr. Clarence Y. Murph

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DENTAL ANATOMY COURSES 6540 and 6543 6540 DENTAL ANATOMY Course Description: The study of the form and function of the human primary and permanent dentitions including but not limited to the nomenclature and development of each. Emphasis is placed on the similarities and differences of each tooth in the human primary and permanent dentitions. 6540 DENTAL ANATOMY Course Objective: Students will learn to fully understand and describe the nomenclature of both the human primary and permanent dentitions as well as describe the structural and morphological similarities and differences of each tooth comprising the dentitions. 6543 DENTAL ANATOMY-C Course Description: Laboratory hands-on application and creation in wax of the morphological characteristics of each category of tooth in the human permanent dentition. 6543 DENTAL ANATOMY-C Course Objective: By applying learned principles, students will associate and learn to create in wax the morphological features characteristic to each tooth of the human permanent dentition. Emphasis is given to the student developing individual skills as they correlate the dimensional relationships of each tooth’s morphological features with their manual dexterity in a progressive series of procedures.

Learning Materials

1. Textbook: Wheeler’s Dental Anatomy, Physiology, and Occlusion; Major M. Ash, Jr., BS, DDS, MS, MD and Stanley J. Nelson, DDS, MS 8th Edition (2003) 2. Dental Anatomy Manual for Lecture & Laboratory Courses 6540 and 6543, Department of Restorative Sciences, Baylor College of Dentistry, TAMUHSC; 2007 3. Atlas of the Human Dentition; Charles J. Goodacre, DDS, MSD; 2nd edition (2003) 4. Brown & Herbranson’s Dental Anatomy & Interactive 3-D Tooth Atlas; Version 6.0 Paul Brown, DDS, FICD, FACD; Stanford University Medical Center National Biocomputation Center 5. “Typodont” anatomical model of the permanent dentition

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Course Competencies 2.2 Use, assess and integrate into practice new techniques, materials and other

findings applicable to dental practice. 2.3 Communicate professional knowledge to colleagues and patients.

4.2 Perform a physical intraoral and extraoral examination of the patient including assessment of vital signs, radiological examination and supporting diagnostic aids and laboratory tests.

5.4 Identify the presence and extent of diseases of the teeth and supporting structures

5.5 Recognize and identify conditions that adversely affect the patient’s masticatory

functions

Course Director Dr. Charles J. Arcoria Associate Professor, Department of Restorative Sciences Interim Director, Office of Continuing Education & Alumni Services Baylor College of Dentistry Office: Room 732-1 Office for appointments with students: Room 732-1 (please e-mail Dr. Arcoria first to schedule a time) carcoria@bcd.tamhsc.edu (817) 680-0239 (cell phone and voicemail) **Dr. Arcoria has an iPhone device and is always easily reachable by e-mail or a text

IMPORTANT NOTE: Access to Information from the Course Director to D-1 Students. A web-site has been constructed that will be used as a storehouse of files for students throughout the semester (this is a separate location from the College’s Public Share files, which are typically deleted after a few days). Students should access this web-site for the following instructional information: 1. Condensed waxing instructional videos 2. PowerPoint lecture presentation files 3. Tutorial preparation sessions for examinations 4. Various lecture or laboratory audio or video presentations 5. Preparation for taking and passing the National Board Examination Please make a note of the web-site location (you can access this from off campus locations): http://www.carcoria.com/bcd-d1-da-2011/dental-anatomy-2011.htm

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6540 LECTURE - Fall Semester 2011

There are four (4) examinations, including a cumulative final examination. Lecture attendance will be documented with a sign-in sheet. Examinations are equally weighted at 24% each. Attendance is weighted at a total of 4%, meaning that if a student attends all lectures, they will receive a “100” on the attendance weight. If a student misses 1 or more lectures, they will receive a “0” on the attendance weight.

Lecture Exam #1 score = ____________ x .24 (weight) = _____________

Lecture Exam #2 score = ____________ x .24 (weight) = _____________

Lecture Exam #3 score = ____________ x .24 (weight) = _____________

Final Examination score = ___________ x .24 (weight) = _____________

Attendance score = _____________ x .04 (weight) = ______________

Final Lecture Grade = ________________

6543 LABORATORY - Fall Semester 2011

Two (2) exercises weighted at 0.5% each and twelve (12) “projects” that are weighted at 3% each, eleven of them waxing projects evaluated as either pass (acceptable) or fail (unacceptable). If a student receives a passing grade from their instructor, at the end of the appropriate laboratory period or when the project is due, they will receive full credit (grade of 100). If the student receives a failing grade from the instructor, or if the student does not finish the project (and does not have an official excused absence), the student will be given 1 week to finish the project (under the supervision of the Course Director) to receive a grade of 70. If the student does not finish the project within the 1-week time frame, or make up the project because of an official excused absence, the student will receive a grade 0 on the exercise. There are seven (7) practical examinations that are weighted at 9% each, graded on a scale of 0 - 100. Four of the seven practical examinations involve waxing a tooth.

Project #1 (#26 cut) score = ______ x .03 (weight) = _____ Project #2 (#12 cut) score = ______ x .03 (weight) = _____ Project #3 (#20 cut) score = ______ x .03 (weight) = _____ Project #4 (#19 cut) score = ______ x .03 (weight) = _____ Project #6 (#10 typo) score = ______ x .03 (weight) = _____ Project #7 (#11 typo) score = ______ x .03 (weight) = _____ Project #8 (#12 typo) score = ______ x .03 (weight) = _____ Project #9 (#13 typo) score = ______ x .03 (weight) = _____ Project #10 (#14 typo) score = _____ x .03 (weight) = _____ Project #11 (#30 typo) score = _____ x .03 (weight) = _____ Project #12 (#31 typo) score = _____ x .03 (weight) = _____

Total Project weights = __________ Project #5a (drawings) score =_____ x .015 (weight) = ____ Project #5b (#29 typo) score =_____ x .015 (weight) = ____

Total special project weights = _________

Exercise #1 (intro) score = _____ x .005 (weight) = ____ Exercise #2 (stone) score = _____ x .005 (weight) = ____

Total exercise weights = _________ Practical #1 (Morpho) score = _____ x .09 (weight) = _____ Practical #2 (#9 typo) score = _____ x .09 (weight) = _____ Practical #3 (#5 typo) score = _____ x .09 (weight) = _____ Practical #4 (contours) score = _____ x .09 (weight) = _____ Practical #5 (#3 typo) score = _____ x .09 (weight) = _____ Practical #6 (#19 typo) score = _____ x .09 (weight) = _____ Practical #7 (Tooth ID) score = _____ x .09 (weight) = _____

Total Practical weights = ___________

Final Laboratory Grade (add all 4 weights) = ________________

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Evaluation (Tests & Quizzes)

A. Conversation compromises test security during examinations. Accordingly, no talking is permitted

during exams. No test questions will be interpreted on an individual basis. Any student who approaches an instructor during a test will be expected to turn in their exam.

B. Examinations will be administered in the laboratory, to allow for sufficient time to complete an

examination. Examinations are typically 40 questions. Examination time is from 8:00 am to 8:58 pm. The laboratory will begin promptly at 9:05 am. Students will sit in their assigned seats in the laboratory for the examination.

C. All books, notes, backpacks, purses and all other accessories including hats are to be left in the aisles

during examinations. D. Students are not allowed to enter or exit the laboratory once an examination begins. E. Only students with excused absences approved by the Office of Student Services will be permitted to take

make-up exams or remediate missed lecture or laboratory sessions. F. Under no circumstances shall an examination be taken from the testing area. G. Under no circumstances shall a student submit for evaluation examinations or laboratory projects that are

not their own work. H. Cheating on examination or laboratory projects will not be tolerated. Expulsion will be the

recommended punishment. I. Stereo headphones are permitted during laboratory sessions. Due to variations in musical preferences,

please leave the boombox at home. J. Under no circumstances shall a student sign the attendance record for another student. K. Students cannot receive input from faculty or other students during a practical examination. L. Students must be prepared to leave the laboratory at the time a practical examination is scheduled for

completion. Once instructed to do so, failure to leave the laboratory at the appointed time may result in a penalty being assessed on the grade for that practical examination. Students should not return to the lab before the grading is completed.

M. Students must not handle or have in their possession the work of another student without permission of

the owner. N. Students will not be allowed to take lecture examinations, nor complete laboratory projects or practical

examinations early due to personal plans, commitments or circumstances.

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Attendance

Please sit in your assigned seat at every lecture. Those students who sit elsewhere will be marked absent when the attendance is recorded. Attendance at lectures and laboratory sessions is mandatory. The lecture is intended to be a valuable learning experience where viewing the visual aids is important. The laboratory will start and finish required projects each day, so attendance is mandatory in order to avoid lagging behind the rest of the class.

Students entering the lecture hall after the lecture has begun but prior to 8:10 a.m. may be seated in the rear of the classroom in order to sign the attendance sheet once it is circulated to them. Students who arrive for class after 8:10 a.m. will be marked absent for that day.

Those students who faithfully attend every lecture (i.e., students must initial and date next to their name for each lecture) will receive a score of “100” on the weighted 4% portion for the lecture course.

Any student who misses four (4) or more lectures or laboratory sessions combined may have four (4) points subtracted from their final lecture grade average as a penalty.

Excused absences will require remediation. Only absences that are excused through Ms. Moira Allen in the Office of Student Services will be eligible for remediation. A four page typed, double-spaced paper on an appropriate subject chosen by the course director may serve as remediation for a missed lecture.

An additional waxing assignment as determined by the course director will serve as remediation for an excused absence from a laboratory session.

Our primary goal is to make this course a valuable and interesting learning experience for every student. If we can make a significant contribution to your professional development and professional satisfaction we will be gratified. Your attendance and participation is essential to your success.

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REMEDIATION POLICY 6540 AND 6543

All remediation for Dental Anatomy 6540 and 6543 must be completed during the summer following the semester of deficiency. If remediation for a section of either course is indicated and the student fails to accomplish the remediation requirements, the student will be required to make provisions to repeat the course the following fall semester.

The nature of the remediation will be customized to the individual student’s greatest need.

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DENTAL ANATOMY SCHEDULE D-1 STUDENTS

FALL SEMESTER - 2011

Monday, August 15 Lecture: “Introduction to Dental Anatomy” Dr. Arcoria Lab: 1. Intra-oral exam 9:00 a.m. - 10:00 a.m. – non-graded experience 2. Exercise #1 – Intro to Waxing from 10:00 a.m. – 11:50 a.m. Have your Instructor review Exercise #1 by 11:50 a.m. for Pass/Fail grade. Assignment: Read Wheeler, Chapter 1 in preparation for the next lecture.

Wednesday, August 17 Lecture: “Nomenclature - Part I” Dr. Arcoria Lab: 1. Begin Project #1 (PJ-01) Tooth #26 Cut-away tooth.

Turn in at 11:50 a.m., finish next laboratory.

Assignment: Read Wheeler, Chapter 1 in preparation for the next lecture.

Monday, August 22 Lecture: “Nomenclature - Part II” Dr. Arcoria Lab: 1. Complete Project #1 (PJ-01) Tooth #26 Cut-away Finish by 11:50 a.m. 2. Begin Exercise #2 – Stone casts. . This group project is due at 9:00 a.m. on Wednesday, August 31 Assignment: Read Wheeler, Chapter 2 in preparation for the next lecture.

Wednesday, August 24 Lecture: “The Development of Teeth - Part I” Dr. Bryan Lab: 1. Begin Project #2 (PJ-02) Tooth #12 Cut-away – turn in at 11:30 am 2. Discuss Anatomical Features & Drawing Project (PJ-05) 11:30 – 11:50 am (PowerPoint Exercise from 11:30 a.m. – 11:50 a.m.) – due on Wednesday,

September 14 Assignment: Read Wheeler, Chapter 2 continued for the next lecture.

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Monday, August 29 Lecture: “The Development of Teeth - Part II” Dr. Bryan Lab: 1. Finish Project #2 (PJ-02) Tooth #12 Cut-away

Complete by 11:30 am. 2. At 11:30 am, review Morphological Characteristics Exercise in preparation

for Morphological Characteristics Practical (PC-01) on Wednesday, September 7 from 11:10 am – 12:00 noon

Assignment: Complete stone casts exercise for Wednesday, August 31

Wednesday, August 31 Lecture: “Developmental Morphology” Dr. Arcoria Lab: 1. Complete Exercise #2 - Stone casts due at 9:00 a.m. 2. Begin Project #3 (PJ-03) Tooth #20 Cut-away Turn in at 11:50 a.m., finish next laboratory. Assignment: Read Wheeler Chapter 5, in preparation for the next lecture.

Monday, September 5 Labor Day Holiday

Wednesday, September 7 Lecture: “Physiologic Tooth Form” Dr. Bryan Lab: 1. Finish Project #3 (PJ-03) Tooth #20 - Cut-away

Complete by 11:00 a.m. 2. Practical #1 (PC-1) Morphological Characteristics Practical

(PowerPoint Practical Examination from 11:10 a.m. – 12:00 noon) Assignment: Study for Exam #1 including all notes and reading assignments.

Monday, September 12 Lecture: Lecture Exam #1 (covers lectures from August 15 – September 7) Lab: 1. Project #4 (PJ-04) Tooth #19 Cut-away

Turn in at 11:50 a.m. Assignment: Read Wheeler, Chapter 4 in preparation for the next lecture.

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Wednesday, September 14 Lecture: “Lobe Forms and Geometric Concepts” Dr. Bryan Lab: 1. Turn in at 9:00 a.m. Project #5a (PJ-05a) Anatomical Features & Drawing

Exercise 2. Finish Project #4 (PJ-04) Tooth #19 Cut-away

Complete by 11:50 a.m. Have typodonts available for next laboratory. Assignment: Read Wheeler, Chapter 3 in preparation for the next lecture.

Monday, September 19 Lecture: “Primary Dentition – Part I” Dr. York Lab: 1. Begin Project #6 (PJ-06) Tooth #10 - Full crown wax-up

Turn in at 11:50 a.m., finish next laboratory Assignment: Wheeler, Chapter 3 continued for the next lecture.

Wednesday, September 21 Lecture: “Primary Dentition - Part II” Dr. York Lab: 1. Complete Project #6 (PJ-06) Tooth #10 - Full crown wax-up Complete by 11:50 a.m. Assignment: Wheeler, Chapter 4 and 5 continued for the next lecture.

Monday, September 26 Lecture: “Dental Anomalies” Dr. Arcoria Lab: 1. Begin Practical #2 (PC-02) Tooth #9 - Full crown wax-up Turn in at 11:50 a.m., finish next laboratory Assignment: Read Wheeler, Chapter 6 in preparation for the next lecture.

Wednesday, September 28 Lecture: “Permanent Maxillary Incisors” Dr. York Lab: 1. Complete Practical #2 (PC-02) Tooth #9 - Full crown wax-up Complete and turn in at 11:00 a.m. Assignment: Read Wheeler, Chapter 7 in preparation for the next lecture.

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Monday, October 3 Lecture: “Permanent Mandibular Incisors” Dr. York Lab: 1. Begin Project #7 (PJ-07) Tooth #11 - Full crown wax-up

Turn in at 11:50 a.m., finish next laboratory Assignment: Read Wheeler, Chapter 8 in preparation for the next lecture.

Wednesday, October 5 Lecture: “Permanent Canines” Dr. Bryan Lab: 1. Complete Project #7 (PJ-07) Tooth #11 - Full crown wax-up

Complete by 11:50 a.m. Assignment: Read Wheeler, Chapter 9 in preparation for the next lecture.

Monday, October 10 Lecture: “Permanent Maxillary First Premolars” Dr. Arcoria Lab: 1. Begin Project #8 (PJ-08) Tooth #12 - Full crown wax-up Turn in at 11:50 a.m., finish next laboratory Assignment: Wheeler, Chapter 9 continued for the next lecture.

Wednesday, October 12 Lecture: “Permanent Maxillary Second Premolars” Dr. Arcoria Lab: 1. Review Contours & Embrasures Exercise to prepare for Practical #4 2. Complete Project #8 (PJ-08) Tooth #12 – Complete wax-up by 11:50 am Assignment: Study for Exam #2 including all notes and reading assignments.

Monday, October 17 Lecture: Lecture Examination #2 (covers lectures from September 14- October 12) Lab: 1. Begin Practical #3 (PC-03) Tooth #5 - Full crown wax-up

Turn in at 11:50 a.m., finish next laboratory Assignment: Read Wheeler, Chapter 10 in preparation for the next lecture.

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Wednesday, October 19 Lecture: “Permanent Mandibular First Premolars” Dr. Arcoria Lab: 1. Complete Practical #3 (PC-03) Tooth #5 - Full crown wax-up Complete and turn in at 11:00 a.m. Assignment: Wheeler, Chapter 10 continued for the next lecture.

Monday, October 24 Lecture: “Permanent Mandibular Second Premolars” Dr. Arcoria Lab: 1. Practical #4 (PC-04) at 9:00 am – Contours & Embrasures – Powerpoint 2. Project #5b (PJ-05b) - Tooth #29 Full wax-up in one lab Complete and turn in at 11:50 a.m. (only one lab for this project) Assignment: Read Wheeler, Chapter 11 in preparation for the next lecture

Wednesday, October 26 Lecture: “Permanent Maxillary First Molar - Part I” Dr. Arcoria Lab: 1. Project #9 (PJ-09) Tooth #13 - Full crown wax-up Complete by 9:00 a.m. on Dec 9 – To work on outside class 2. Review placement of die lube on #13 & #14 from 9:00 to 9:15 am 3. Begin Project #10 (PJ-10) - Tooth #14 - Full crown wax-up Turn in at 11:50 a.m., finish next laboratory Note: #13 & #14 will be cast in Dental Materials in the spring Assignment: Wheeler, Chapter 11 continued for the next lecture.

Monday, October 31

Lecture: “Permanent Maxillary First Molars - Part II” Dr. Arcoria Lab: 1. Complete Project #10 (PJ-10) Tooth #14 - Complete wax-up by 11:50 a.m. Note: #13 & #14 will be cast in Dental Materials in the spring Assignment: Wheeler, Chapter 11 continued for the next lecture.

Wednesday, November 2

Lecture: Permanent Maxillary Second Molars Dr. Arcoria Lab: 1. Begin Practical #5 (PC-05) Tooth #3 - Full crown wax-up Turn in at 11:50 a.m., finish next time Assignment: Wheeler, Chapter 11 continued for the next lecture.

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Monday, November 7

Lecture: Permanent Maxillary Third Molars Dr. Bryan Lab: 1. Complete Practical #5 (PC-05) Tooth #3 - Full crown wax-up Finish and turn in at 11:00 a.m. Assignment: Study all notes & reading assignments in preparation for Exam #3.

Wednesday, November 9

Lecture: Lecture Exam #3 (Covers lectures from Oct. 19- Nov. 7) Lab: 1. Begin Project #11 (PJ-11) Tooth #30 - Full crown wax-up Turn in at 11:50 a.m. Assignment: Read Wheeler, Chapter 12 in preparation for the next lecture.

Monday, November 14

Lecture: Permanent Mandibular First Molars Dr. Arcoria Lab: 1. Continue with Project #11 (PJ-11) Tooth #30 - Full crown wax-up Complete by 11:50 am, finish next laboratory Assignment: Wheeler, Chapter 12 continued for the next lecture.

Wednesday, November 16

Lecture: Permanent Mandibular Second Molars Dr. Arcoria Lab: 1. Complete Project #11 (PJ-11) Tooth #30 - Full crown wax-up Finish by 10:00 a.m. 2. Begin Practical #6 (PC-06) Tooth #19 - Full crown wax-up - from 10:15 a.m. to 11:50 a.m. – Turn in at 11:50 a.m. 3. Review of Tooth Identification Exercise (11:35 a.m. to 11:50 a.m.) In preparation for Tooth ID Practical (PC-07) on Wednesday, December 7 Assignment: Wheeler, Chapter 12 continued for the next lecture.

Monday - Friday, November 21 - 25 Thanksgiving Break

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Monday, November 28

Lecture: Permanent Mandibular Third Molars Dr. Bryan Lab: 1. Continue with Practical #6 (PC-06) Tooth #19 - Full crown wax-up Turn in at 11:50 a.m., finish next laboratory. Assignment: Read Wheeler, Chapter 13 in preparation for the next lecture.

Wednesday, November 30

Lecture: Pulpal and Root Morphology - Part I Dr. Arcoria Lab: 1. Finish Practical #6 (PC-06) Tooth #19 - Full crown wax-up Complete and turn in at 11:00 a.m. Assignment: Wheeler, Chapter 13 continued for the next lecture.

Monday, December 5

Lecture: Pulpal and Root Morphology - Part II Dr. Arcoria Lab: 1. Begin Project #12 (PJ-12) Tooth #31 - Full crown wax-up Turn in at 11:50 a.m., finish next laboratory. Assignment: Study all notes and reading assignments for the next lecture.

Wednesday, December 7

Lecture: Final Examination Review Dr. Arcoria Lab: 1. Practical #7 (PC-07) - Tooth Identification PowerPoint 9:00 a.m. - 9:50 a.m.

2. Finish Project #12 (PJ-12) Tooth #31 - Full crown wax-up Complete and turn in at 11:50 a.m. 3. Project #9 (PJ-09) - Have Instructor look and approve (10:00 am – 11:50 am) Tooth #13 full crown wax-up for Dental Materials Laboratory Note: #13 & #14 will be cast in Dental Materials in the spring Assignment: Study all notes and reading assignments in preparation for the final exam EXAM WEEK DECEMBER 12-16

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NOMENCLATURE Fall 2011

Charles J. Arcoria, D.D.S., M.B.A.

I. Nomenclature

A. Maxilla- (upper jaw) Maxillary arch, maxillary teeth, etc. B. Mandible- (lower jaw) Mandibular arch, mandibular teeth, etc. C. Temporal Bone- temporomandibular joint (TMJ) (3 axes of rotation) D. Dentition- the natural teeth in the jawbone

1. Primary Dentition: (aka Deciduous) number = 20 2. Permanent Dentition: (aka Secondary or adult) = 32 3. Succedaneous Dentition: Permanent teeth that succeed primary teeth 4. Mixed Dentition: Transition period when both primary and permanent

teeth are present in the dental arch. II. Human Dentition: Tooth Names:

A. Primary: per quadrant 1. Incisors (2): Central Incisor & Lateral Incisor 2. Canine (1) (aka “cuspid”) 3. Molars (2): 1st molar & 2nd molar 4. Total = 5 (10 per arch; 20 total)

B. Permanent: per quadrant 1. Incisors (2): Central Incisor & Lateral Incisor 2. Canine (1) (aka “cuspid”) 3. Premolars (2) (aka “bicuspids”): 1st Premolar & 2nd Premolar 4. Molars (3): 1st molar, 2nd molar, & 3rd molar 5. Total = 8 (16 per arch; 32 total)

C. Anterior vs. Posterior teeth 1. Anterior: canine to canine in each arch

a. typically single rooted and used to “incise foods” b. important in phonetics

2. Posterior: remaining teeth in the arch (premolars & molars) a. multirooted except for some premolars and used for chewing &

gnashing b. have an “occlusal surface”

III. Tooth Numbering Systems:

A. Universal (#A-#T; #1-#32) B. Quadrant (Zsigmondy-Palmer) C. FDI- Federation Dentaire Internationale

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IV. Tooth Anatomy A. Crown:

1. Anatomic crown: that portion of the tooth covered by enamel 2. Clinical crown: that portion of the tooth clinically visible 3. “Coronal”: pertaining to or having to do with the crown

B. Root: 1. That portion of the tooth covered with cementum 2. “Radicular”: pertaining to or having to do with the root

C. Cementoenamel Junction (“CEJ”) aka the “cervical line” V. Tooth Tissues

A. Enamel (hard): outer covering of the working portion of the tooth B. Cementum (hard): provides for a ligamentous attachment of the root to the

alveolar bone (tooth socket) C. Dentin (hard): constitutes the bulk of the tooth D. Pulp (soft): nerves, blood vessels, lymphatics, etc. inside the pulp chamber

VI. Surfaces of the Teeth: Each tooth has 5 surfaces or “sides”

A. Mesial: that surface of the tooth closest to the midline B. Distal: that surface of the tooth farthest from the midline C. Facial: that surface of the tooth closest to the face

1. Labial (lip): alternative term used for anterior teeth 2. Buccal (cheek): alternative term used for posterior teeth

D. Lingual: that surface of the tooth closest to the tongue (“palatal” term sometimes used for maxillary posterior teeth because that surface is adjacent to the palate).

E. Occlusal: the biting surface of posterior teeth F. Incisal: the biting surface of anterior teeth G. Proximal: the surface of a tooth facing toward an adjacent tooth in the same arch H. Axial: the surfaces of a tooth that are parallel to its long axis

VII: Anatomical Landmarks of Teeth (positive):

A. Cusp: an elevation or mound on the crown portion of the tooth B. Ridge: any linear elevation on the surface of a tooth

1. Triangular: descends from the tips of the cusps of posterior teeth toward the central part of the occlusal surface. Each cusp has only one triangular ridge.

2. Cuspal: ridges that descend from the tips of cusps in directions other than toward the central part of the occlusal surface

3. Oblique (unique to maxillary molars): obliquely crosses the occlusal surface. Formed by the triangular ridge of the DF cusp & the distal cuspal ridge of the ML cusp.

4. Transverse: formed by the union of two triangular ridges transversely crossing the occlusal surface of a posterior tooth.

5. Marginal: the rounded borders of enamel that form the mesial & distal margins of the occlusal surface of posterior teeth or lingual surface of anterior teeth.

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6. Lingual: ridges that extend from the cusp tip in a lingual direction a. Anterior teeth: Unique to the canine; run from the cusp tip to the

cingulum b. Posterior teeth: Ridges (other than triangular ridges) that extend

lingually from the tip of a cusp 7. Incisal: ridges that extend from the incisal most portion of the mesial

& distal marginal ridges of incisors. The incisal edge is the most incisal portion of the ridge and used to “incise” or tear foods

8. Cervical: the height of contour on the cervical portion of the facial or lingual surface of a tooth. It will run in a mesiodistal direction.

a. This occurs at the cervical (neck) 1/3 of the tooth b. Anterior teeth have a facial and a lingual cervical ridge c. Posterior teeth have only a facial cervical ridge

C. Cingulum: the lingual lobe of an anterior tooth making up the bulk of the cervical ⅓ of the lingual portion of the tooth.

D. Tubercle: a smaller elevation of some portion of the crown produced by an extra formation of enamel.

VIII: Anatomical Landmarks of Teeth (negative): A. Fossa(e): an irregular depression or concavity.

1. Lingual: found on the lingual surfaces of anterior teeth (canines can have two- a mesiolingual fossa and a distolingual fossa.

2. Central: found at the bottom of the occlusal surfaces of molars. Formed by converging ridges ending at a central point in the bottom of the depression where there is a junction of grooves.

3. Triangular: a triangular shaped depression found on the occlusal surface of posterior teeth. The base of the triangle is a marginal ridge.

B. Sulcus: A depression or valley on the surface of a tooth between ridges & cusps, the inclines of which meet at an angle. There is a developmental groove (see below) at the junction of these inclines.

C. Groove: a definitive line on the surface of the tooth. 1. Developmental: a linear depression between the primary parts

(developmental lobes) of the tooth. 2. Supplemental: a less distinct linear depression on the surface of the tooth

that is supplemental to the developmental groove i.e. does not mark the junction of the primary parts of the tooth.

D. Developmental Depression: A defined recessed area on the surface of a tooth found between two primary parts of a crown or root E. Pit: pinpoint depressions located at the junction or terminus of developmental

grooves.

IX. Gross Divisions & Junctions A. Division into Thirds:

1. Anterior Teeth a. Crown:

(1) facial or lingual view: (a) mesiodistally: mesial, middle, distal (b) incisocervically: incisal, middle, cervical

(2) proximal view: facial, middle, lingual b. Root: cervical, middle, apical

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2. Posterior Teeth

a. Crown: (1) facial or lingual view:

(a) mesiodistally: mesial, middle, distal (b) occlusocervically: occlusal, middle, cervical

(2) proximal view: facial, middle, lingual b. Root: cervical, middle, apical

B. Line Angle: an angle formed by the junction of any two of the five surfaces of the tooth.

C. Point Angle: The point at which three of the tooth’s five surfaces converge. D. Occlusal Table: An area on the chewing surface of posterior teeth bordered by

the crests of the marginal ridges mesially & distally and by the cusp tips facially & lingually.

Identify: 1. Arch 11. Incisal surface 23. Incisal ridge 31. Supplemental groove 2. Quadrant 12. Axial surface 24. Facial ridge 32. Pit 3. Names of teeth 13. Proximal surface 25. Lingual ridge 33. Coronal 4. Universal # 14. Contact area 26. Occlusal table 34. Radicular 5. Mesial surface 15. Cusp names 27. Central fossa 35. Cervical line 6. Distal surface 16. Cuspal ridges 28. Triangular fossa 36. CEJ 7. Facial surface 17. Cingulum 29. Lingual fossa 37. Root apex a. labial 18. Marginal ridge 30. Develop. grooves: 38. Division into thirds b. buccal 19. Triangular ridge a. central 39. Line Angles 8. Lingual surface 20. Transverse ridge b. facial 40. Point Angles 9. Palatal surface 21. Oblique ridge c. lingual 41. Crown outline form 10. Occlusal surface 22. Cervical ridge d. other 42. Develop. depression

Location of Proximal Contact Areas Facial View

Maxillary anterior teeth: IJ JM JM

Mandibular anterior teeth: II II IM

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The Universal Tooth Numbering System

Permanent Dentition

1. The mandibular right second premolar is tooth #_____________ 2. The maxillary left first premolar is tooth #___________ 3. The permanent maxillary left lateral incisor is tooth # __________ 4. The permanent maxillary left second molar is tooth # ___________ 5. The premolars on the right side of the mandible are tooth numbers ______ & ______ 6. The permanent maxillary canines are tooth numbers ______ & ______ 7. The permanent mandibular canines are tooth numbers ______ & ______ 8. The permanent maxillary central incisors are tooth numbers ______ & ______ 9. The permanent mandibular central incisors are tooth numbers ______ & ______ 10. The mandibular third molars are tooth numbers ______ & ______ It will be easier to orient yourself throughout the dental arches if you remember some teeth in groups: 11.One should memorize that the four permanent canines are tooth numbers:

______, ______, ______, and ______ 12. The permanent maxillary first molars are tooth numbers ______ and ______ 13. The permanent mandibular first molars are tooth numbers ______ and ______ 14. The posterior teeth in the mandibular left quadrant are tooth numbers ______, ______, ______,

______, and ______ 15. For faster orientation within the oral cavity, one should memorize the four permanent

first molars are tooth numbers ______, ______, ______, and ______ 16. The permanent molars in the mandibular right quadrant are tooth numbers ______ , ______ &

_____ 17. Generally speaking, the mandibular first molars are the first permanent teeth to appear

in the oral cavity. The molars are tooth numbers ______ and ______. Why are they often called the “six year molars”?

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The Universal Tooth Numbering System

Primary Dentition

18. The primary maxillary left second molar is tooth number ______ 19. The primary maxillary right second molar is tooth number _____

20. The primary mandibular left second molar is tooth number ______

21. The primary mandibular right second molar is tooth number ______

22. The primary maxillary central incisors are tooth numbers ______ and ______

23. The primary mandibular central incisors are tooth numbers ______ and ______

24. The primary mandibular left canine is tooth number ______

25. The primary maxillary right first molar is tooth number ______

Convention for Naming Teeth: dentition – arch – side – name of tooth, i.e.: Tooth #7 is the permanent maxillary right lateral incisor Tooth #K is the primary mandibular left second molar 26. Tooth # 1 is the _______________________________________________________ 27. Tooth # I is the _______________________________________________________

28. Tooth #12 is the ______________________________________________________

29. Tooth #18 is the ______________________________________________________

30. Tooth #B is the _______________________________________________________

31. Tooth #E is the _______________________________________________________

32. Tooth #28 is the ______________________________________________________

33. Tooth #5 is the _______________________________________________________

34. The total number of molars per arch in the permanent dentition is __________

35. The total number of molars per quadrant in the permanent dentition is _________

36. The number of premolars in the primary dentition is _______

37. The total number of incisors in the left quadrants of the mouth is _______

21

Chapter 2- The Development of Teeth Burt Bryan, D.D.S.

Fall, 2011

I. Importance of having knowledge & understanding: A. Clinical practice B. Morphologic variations C. Calcification & eruption schedule D. Forensics E. Anthropology F. Paleontology & comparative anatomy

II. Chronology of Primary Tooth Development

A. Terms 1. Chronology: the time table of the development and eruption of the

teeth 2. Calcification: the process by which the tissues of the developing tooth

become hardened by the deposits of calcium salts 3. Eruption: the continuous movement of the tooth as it develops from its

bud stage until the root completely forms or it reaches occlusal contact 4. Emergence: denotes the stage of tooth development and eruption when

it emerges through the gingival tissue into the oral cavity B. Sequence of Development within the Dental Follicle (a sac-like structure that

contains the developing tooth within the bones of the jaws). 1. Positive anatomy: cusp tips or incisal edges develop first from

developmental lobes (described below) 2. Negative anatomy: fossae & grooves develop as the centers of

calcification merge upon one another 3. Roots: develop last ending at the apex (root tip)

C. Calcification schedule of Primary Teeth 1. 13-16 weeks in utero: calcification of the primary teeth begins 2. Sequence: CI > 1st molar > LI > Canine > 2nd molar 3. 18-20 weeks in utero: all primary teeth have initiated calcification

D. Eruption & Emergence Schedule (Table 2-1, p. 32; Fig. 2-3, p. 33) 1. Mn Central incisors fist primary teeth to emerge followed by Mx CI 2. Sequence: CI > LI > 1st molar > Canine > 2nd molar 3. Mx 2nd molar last to emerge around 29 months of age 4. Root formation of all primary teeth completed by 39 months of age

E. Anomalies of Tooth Eruption Patterns 1. Natal teeth: baby is born with teeth (generally not well developed) 2. Neonatal teeth: teeth that emerge during the first month after birth 3. Anodontia (missing teeth): Mn CI most common primary tooth;

genetic trait 4. Supernumerary teeth: “extra” teeth; “mesiodens” forms between the

two maxillary central incisors

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F. Neurobehavioral Mechanisms 1. Emergence of the primary teeth important for the development of oral

motor & masticating skills 2. Jaw movements & mastication skills develop concurrently with the

development of the dentition and the neuromuscular system. 3. Mature controlled neuromuscular movements of the mandible require

the teeth to come into occlusal contact 4. Proprioceptive input from the periodontium provides information for

coordinated jaw movements for chewing and tongue functions

III. Transitional “Mixed” Dentition Period

A. Begins with the emergence & eruption of the Permanent Mandibular 1st molar distal or posterior to the primary mandibular 2nd molar.

B. Ends with the loss of the last primary tooth (maxillary canine) Age 11-12 C. Permanent teeth do not begin their eruptive movements until after the crown

of the tooth is formed D. Premature loss of Primary teeth (neglect, congenital absence, or anomalies)

may lead to a lack of sufficient space to accommodate the permanent successor

First Evidence Crown Root of Calcification Completed Eruption Completion Exfoliated

Maxillary Tooth # (weeks in utero) (months) (age in mths) (years) (years) i1 E, F 14 1.5 10 1.5 6.5 i2 D, G 16 2.5 11 2 7.5 C C, H 17 9 19 3.25 11

m1 B, I 15 6 16 2.5 10 m2 A, J 19 11 29 3 11

First Evidence Crown Root of Calcification Completed Eruption Completion Exfoliated Mandibular Tooth # (weeks in utero) (months) (age in mths) (years) (years)

i1 P, O 14 2.5 8 1.5 6.5 i2 Q, N 16 3 13 1.5 7.5 C R, M 17 9 20 3.25 10.5

m1 S, L 15.5 5.5 16 2.25 10 m2 T, K 18 10 27 3 11

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IV. The Permanent Dentition A. Develop from 4 or more centers of calcification called “developmental lobes”:

1. Posterior lobes develop into cusps; posterior teeth with five cusps developed from five developmental lobes.

2. Anterior teeth have three facial developmental lobes initiating their development at the incisal edge known as “mamelons”.

a. Mamelons wear in time resulting in a smooth incisal edge. b. Areas of coalescence on the labial surface between the

developing lobes are known as “developmental depressions”. c. “Imbrication lines” are (negative anatomy) lines in the

enamel that are parallel to the CEJ. They are the result of an overlapping of enamel deposits at the cervical area. The positive anatomy is called “perikymata”.

3. Cingulum = the 4th developmental lobe of anterior teeth; raised area of enamel located on the lingual surface of the crown occupying the cervical one-third to one-half of the lingual surface.

B. Positioning of permanent tooth follicle: 1. Anterior teeth: lingual to the deciduous roots. 2. Premolars: within the bifurcation of the primary molar roots. 3. Molars: distal or posterior to primary molar teeth. 4. Succedaneous teeth: those permanent teeth that succeed or take the

place of primary teeth. C. Chronology of Calcification, Eruption & Emergence of the Permanent Teeth:

1. Reliable means of determining age for anthropological or forensic purposes.

2. Mandibular teeth generally (but not always) precede their maxillary counterparts in the eruption process.

3. Begins with the eruption into the oral cavity of the permanent mandibular 1st molar (age 6).

4. Mixed dentition phase ends with the exfoliation of the last primary tooth (usually the maxillary canines).

5. Crowns of permanent teeth are completely formed before they emerge. 6. Roots of the permanent teeth are not completely formed (~50%) when

the teeth initially emerge into the oral cavity. 7. Schedule of calcification, emergence (eruption), and root completion

of the permanent teeth: Arch Overall Crown Eruption or Root Order of Order of

Maxillary Tooth # Calcification Completed Emergence Completion Eruption Eruption Central 8, 9 3.5 months 4.5 years 7.5 years 10 years 2 5 Lateral 7, 10 1 year 4.5 years 8.5 years 11 years 3 6 Canine 6, 11 4.5 months 6.5 years 11.5 years 14 years 6 12

1st Premolar 5, 12 2 years 5.5 years 10 years 12.5 years 4 8 2nd Premolar 4, 13 2 years 6.5 years 10.5 years 13 years 5 9

1st Molar 3, 14 Birth 3 years 6 years 9 years 1 2 2nd Molar 2, 15 3 years 7.5 years 12.5 years 15 years 7 14 3rd Molar 1, 16 9 years 14 years 19 years 21.5 years 8 16

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Arch Overall Crown Eruption or Root Order of Order of

Mandibular Tooth # Calcification Completed Emergence Completion Eruption Eruption Central 24, 25 3.5 months 4.5 years 6.5 years 9 years 2 3 Lateral 23, 26 3.5 months 4.5 years 7.5 years 10 years 3 4 Canine 22, 27 4.5 months 6.5 years 9.5 years 13 years 4 7

1st Premolar 21, 28 2 years 5.5 years 11 years 12.5 years 5 10 2nd Premolar 20, 29 2 years 6.5 years 11.5 years 13.5 years 6 11

1st Molar 19, 30 Birth 3 years 6 years 9 years 1 1 2nd Molar 18, 31 3 years 7.5 years 12 years 14.5 years 7 13 3rd Molar 17, 32 9 years 14 years 19 years 21.5 years 8 15

V. Anomalies of Permanent tooth development and eruption:

A. Tetracycline staining B. Fluorosis C. Peg-shaped lateral incisor D. Ectopic eruption E. Impaction F. Supernumerary teeth G. Anodontia or partial anodontia H. Ankylosis (fusion of a tooth to the alveolar bone)

VI. The Dental Pulp

A. Connective tissue organ containing arteries, veins, nerves, & a lymphatic system.

B. Large with young, newly erupted teeth, becomes smaller as tooth ages. C. Principal function is to form the dentin of the tooth:

1. Primary Dentin: formed prior to root completion 2. Secondary Dentin: formed after root completion 3. Tertiary Dentin: formed as a reaction to injury or noxious stimuli

VII. Dental Age

A. Juvenile years: based on the stage of eruption of the permanent teeth and root resorption of the primary teeth.

B. Development of the dentition is the best physiologic indicator of the age of juveniles.

C. Adult, fully erupted dentition is less precise and is dependent on attrition, wear, and other corroborating features to provide a reliable estimate.

D. During dental development, the crowns and roots of teeth are the tissues least affected by environmental or nutritional influences.

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Developmental Morphology Charles J. Arcoria, D.D.S., M.B.A.

Rationale: Compare & contrast the dentitions of other vertebrates There are trends or commonalities regarding tooth development Know the various tooth and cusp forms Know the various jaw outlines and positions Arch Form Alignment & Terminology: Isognathous: equal-jawed or symmetrical arch alignment Anisognathus: unequal-jawed or asymmetrical arch alignment Humans have an arch alignment that is considered “partially isognathous” Cusp Design in Vertebrates: Bunodont: tooth-bearing conical cusps Selenodont: crescent-shaped cusps Humans have a primarily bunodont form that may change with age to a partially selenodont shape Diet & Mandibular Movement in Vertebrates: Carnivorous: meat ingesting, bunodont cusp form, and vertical mandibular movement Herbivorous: plant ingesting, selenodont cusp form, and horizontal mandibular movement Omnivorous: plant and animal ingesting, primarily bunodont cusp form, both vertical and horizontal mandibular movement Mammalian Phylogenetic Development:

<<Haplodont <<Triconodont <<Tritubercular

<<Tritubercular Molar <<Quadritubercular Molar

<<Quadritubercular Molar with Talon Cusps

Maxillary First Molar Primitive Cusp Names: Mandibular 1st Molar Primitive Cusp Names:

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The Primary Dentition Beverly York, D.D.S.

I. Importance A. Function (chewing & speech) B. Appearance C. Proper development of bone as well as the symmetrical growth and development to the jaws D. Maintain the space and serve as guides for the succedaneous permanent teeth E. Psychological well-being of the child. Must be

be maintained to avoid discomfort & mouth odors

II. Nomenclature A. Number of teeth and names B. Universal Numbering System C. Eruption, Emergence & Exfoliation D. Primary Molars replaced by “permanent” Premolars

III. Contrasts Between Primary & Permanent Teeth:

A. Overall size B. Cervical ridges C. Color D. Anterior teeth

1. Crowns: are wider mesiodistally relative to their crown length than are the permanent anterior teeth 2. Roots: narrower & longer when compared to respective crowns

E. Posterior teeth 1. Crowns: Primary molars larger than (permanent) premolars 2. Roots: thinner & more flared than permanent molars

F. Pulp chambers: large with high pulp horns G. Enamel: thin with consistent depth H. Dentin: limited thickness

IV. Chronology of calcification, eruption and emersion of Primary Teeth:

A. Maxillary Arch:

First Evidence Crown Root of Calcification Completed Eruption Completion Exfoliated

Maxillary Tooth # (weeks in utero) (months) (age in mths) (years) (years) i1 E, F 14 1.5 10 1.5 6.5 i2 D, G 16 2.5 11 2 7.5 C C, H 17 9 19 3.25 11

m1 B, I 15 6 16 2.5 10 m2 A, J 19 11 29 3 11

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B. Mandibular Arch:

First Evidence Crown Root of Calcification Completed Eruption Completion ExfoliatedMandibular Tooth # (weeks in utero) (months) (age in mths) (years) (years)

i1 P, O 14 2.5 8 1.5 6.5 i2 Q, N 16 3 13 1.5 7.5 C R, M 17 9 20 3.25 10.5

m1 S, L 15.5 5.5 16 2.25 10 m2 T, K 18 10 27 3 11

V. General Considerations:

1. Primary teeth are smaller than permanent teeth. 2. The crowns of primary teeth are a smaller percentage of the

overall tooth than they are of permanent teeth, i.e., the crown-to-root ratio is smaller.

3. Crowns of primary teeth appear not only shorter but also “fatter” than those of permanent teeth.

4. Molar roots of primary teeth are long and slender with little or no root trunk; roots themselves have a marked bowing and flaring.

5. The anterior primary teeth are constricted at the cervical line producing conspicuous lingual and cervical bulges.

6. Primary molars have a facial bulge (cervical ridge) but lack a conspicuous lingual bulge (ht. of contour).

7. Cervical ridges of primary teeth are more pronounced than in permanent teeth.

8. Facial and lingual surfaces of primary teeth from the heights of contour to the occlusal or incisal edge are flatter than those found on permanent teeth. No mamelons are seen on primary anterior teeth.

9. The enamel of primary teeth is thinner than that of permanent teeth.

10. Primary teeth are considerably whiter than permanent teeth. 11. Multiple diastemas (gaps between teeth) are normally seen in the

primary arch. 12. The primary arch is more circular than the permanent arch. 13. All teeth in the primary dentition are replaced by the same teeth in

the permanent dentition except the primary molars, which are replaced by the permanent premolars.

14. The primary teeth generally resemble the permanent teeth that replace them except for the primary molars. The primary maxillary and mandibular 2nd molars very much resemble the permanent maxillary and mandibular 1st molars. The primary maxillary and mandibular 1st molars do not resemble any teeth of the permanent dentition.

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15. Because of its prominent mesiolingual and mesiofacial cusps, the

primary maxillary first molar is the primary molar that most resembles a premolar.

16. The primary mandibular first molar has the most unique facial cervical ridge or bulge.

17. The primary mandibular first molar has a prominent transverse ridge connecting the two mesial cusps.

VI. The Primary Anterior Teeth:

A. Maxillary central incisor is replaced by the permanent maxillary central incisor and is similar in its appearance except in the following ways:

1. The labial surface is smoother and it has no mamelons 2. The cingulum may be more prominent 3. It has a significant cervical constricture with accompanying facial

and lingual cervical bulges. 4. The cervicoincisal measurement of the crown is less than the

mesiodistal measurement.

B. Maxillary lateral incisor is replaced by the permanent maxillary lateral incisor and is similar in its appearance except in the following ways:

1. The labial surface is smoother 2. It has more distinctive lingual anatomy 3. It has a significant cervical constricture with accompanying facial

and lingual cervical bulges.

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C. Maxillary canine is replaced by the permanent maxillary canine and is

similar in its appearance except in the following ways:

1. Facial crown outline is diamond shape rather than trapezoidal 2. The labial surface is smoother 3. It has a more prominent (almost cusp-like appearance) cingulum 4. Its mesial and distal contact areas are at the same level 5. Its mesial cuspal ridge is longer than its distal cuspal ridge 6. The OC height measures less than mesiodistal measurement

D. Mandibular central incisor is replaced by the permanent mandibular central incisor and is similar in its appearance except in the following ways:

1. Its labial surface is smooth, unmarked and flat. 2. It has a prominent cingulum 3. It has a notable cervical constricture with accompanying facial and

lingual cervical bulges.

E. Mandibular lateral incisor is replaced by the permanent mandibular lateral incisor and is similar in its appearance except in the following ways:

1. It has a prominent cingulum 2. It has a notable cervical constricture with accompanying facial and

lingual cervical bulges.

F. Mandibular canine is replaced by the permanent mandibular canine and is similar in its appearance except in the following ways:

1. Facial crown outline form is arrow shaped 2. It has a smooth labial surface 3. The distal cuspal ridge is longer than the mesial cuspal ridge

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VII. The Primary Posterior Teeth:

A. Maxillary first molar is replaced by the maxillary first premolar. It does not resemble any teeth of the permanent dentition.

1. Most atypical of all of the molars as it has characteristics of both a

premolar and of a molar. 2. Because of its divisions on the occlusal surface and its root form,

it is classified as a molar. 3. Two major cusps, mesiolingual and mesiofacial. Smaller

distofacial cusp usually present and distolingual cusp may or may not be discernable.

4. Occlusal crown outline is trapezoidal. Tooth converges lingually and distally; facial surface measures longer than the lingual and the mesial surface measures longer than the distal.

5. Occlusal table is rectangular with a facial developmental groove separating the two facial cusps.

6. Heights of contour are prominent with a distinct cervical ridge on the facial surface.

7. Has three roots that are very divergent.

B. Maxillary 2nd molar is replaced by the maxillary 2nd premolar. It is similar in its appearance to the permanent maxillary 1st molar except in the following ways:

1. It has a squattier and more bulbous appearance. 2. It has a more prominent cervical bulge. 3. It has very little (if any) root trunk.

C. Mandibular first molar is replaced by the mandibular first premolar. It does not resemble any teeth in the permanent dentition.

1. It looks more like a molar than does the primary maxillary 1st molar 2. It generally has four cusps, two facial and two lingual. The mesio-

facial and mesiolingual cusps are the largest. Usually, a transverse ridge can be identified between the mesiofacial and mesiolingual cusps.

3. The mesial profile is straight and the distal profile is highly convex.

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4. The occlusal crown outline form is rhomboidal because of the

significant cervical ridge (bulge) on the mesial half of the facial surface.

5. The crown demonstrates lingual and distal convergence. 6. The mesial view shows a very prominent facial cervical ridge with

the cervical line moving occlusally in a faciolingual direction. 7. A facial groove separates the two facial cusps 8. Has two roots, one mesial (longer) and one distal

D. Mandibular 2nd molar is replaced by the mandibular 2nd premolar. It is similar in its appearance to the permanent mandibular 1st molar except in the following ways:

1. Its two roots are more divergent and there is no root trunk 2. Its significant cervical bulge 3. All three buccal cusps (mesiofacial, distofacial and distal) are

equal in size. The distal cusp is the smallest cusp of the permanent mandibular 1st molar.

An Overview

of Each Tooth in the

Permanent Dentition

32

33

PERMANENT MAXILLARY CENTRAL INCISOR

1. FACIAL ASPECT - MAXILLARY CENTRAL INCISOR

a. Crown length (10.5 mm) greater than crown width (8.5 mm).

b. Crown width at contact area greater than at cervix. c. Crown outline said to be a trapezoid with shorter

parallel side at cervix. d. Incisal edge relatively straight. Young tooth may

show evidence of mamelons. e. Distal incisal angle more rounded than mesial incisal

angle. The mesial incisal angle is said to be a sharp (almost 90°) angle.

f. Mesial crown outline straighter than distal crown outline.

g. Mesial proximal contact (greatest curvature of mesial outline) is located nearer incisal edge than distal proximal contact (greatest curvature of distal outline). Mesial contact area is within the incisal 1/3 of the crown. The distal contact is at the level of the junction of the incisal and middle thirds.

h. Cervical outline of crown is slightly concave incisallyand the arc of the curvature is said to be part of a semicircle.

i. Facial surface is relatively flat (only slightly convex) in its incisal two thirds.

j. Facial surface may show some evidence of shallow vertical developmental depressions delineating lobe structure.

k. Facial surface may show horizontal ridges at the cervical one-third representing differing rates of enamel formation during normal growth patterns. The raised portions of the ridges (positive anatomy) are termed “perikymata” and the horizontal grooves (negative anatomy) are termed “imbrication lines.”

l. Outline of root is cone shaped with a relatively blunt apex usually located slightly distal to center line of tooth.

M D

34

2. LINGUAL ASPECT - MAXILLARY CENTRAL INCISOR

a. Outline of the crown and root is the reverse of the facial outline.

b. Cervical outline of crown is more concave (toward incisal) than on facial (not a semicircle).

c. Lingual fossa in incisal ½ of crown surface is described as a broad, shallow “dish-shaped” depression bound by the incisal ridge, the mesial and distal marginal ridges and the cingulum. It is trapezoidal in shape.

d. A well developed cingulum occupies the cervical ½ of the crown. Its greatest curvature lingually and the crest of the cervical line gingivally will be slightly distal to the mesiodistal long axis bisector of the crown.

3. MESIAL ASPECT - MAXILLARY CENTRAL INCISOR

a. Crown outline is triangular with apex at incisal. b. Incisal ridge is centered labiolingually. c. The cervical line viewed from the mesial aspect curves

incisally for 1/3 of total crown length. (This is the greatest curvature of the cervical line incisally or occlusally found on any tooth).

d. Greatest curvature of the crown outline facially and lingually will be in the cervical 1/3 of the crown at the crests of the facial and lingual cervical ridges. These crests are opposite one another and at the same level.

e. The facial outline of the crown from the crest of the facial cervical ridge to the incisal ridge is relatively flat (shows very little convexity).

f. The lingual outline of the crown from the cingulum to the incisal ridge is slightly concave.

g. The root is cone shaped with the blunt apex centered faciolingually.

h. The root surface is relatively smoothly convex and has no developmental root depressions.

D M

L F

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4. DISTAL ASPECT - MAXILLARY CENTRAL INCISOR

a. Greatest faciolingual width is in cervical 1/3 of the crown.

b. Incisal ridge and apex of the root are in line with each other along the long axis of the tooth.

c. Note that convexity of the outline of the cingulum begins approximately halfway between the incisal ridge and the cervical line on the lingual.

d. The curvature of the cervical line incisally is less on the distal than it is on the mesial surface.

e. The distal root surface has no developmental root depression and is relatively smoothly convex.

5. INCISAL ASPECT - MAXILLARY CENTRAL INCISOR

a. Mesiodistal width is greater than the faciolingual diameter.

b. Interproximal contact areas (greatest curvature mesially and distally) are centered faciolingually.

c. Incisal edge (ridge) is relatively straight and perpendicular (at a 90° angle) to the mesiodistal bisecting plane. It is positioned along (parallel to) the faciolingual bisecting plane.

d. Crest (greatest curvature lingually) of the cingulum is slightly distal to the afore mentioned mesiodistal bisecting plane of the crown.

e. Crown outline converges lingually. f. Mesiofacial and distofacial line angels are relatively

prominent and the surface outline between them relatively straight.

F L

D M

36

DENTAL ANATOMY PRINCIPLE CHARACTERISTICS OF A

PERMANENT MAXILLARY LEFT CENTRAL INCISOR

1. INCISAL ASPECT a. incisal ridge centered faciolingually b. incisal ridge perpendicular to the mesiodistal bisector

2. FACIAL ASPECT a. conical shaped root b. mesioincisal line angle square c. distoincisal line angle rounded d. crown outline trapezoidal

3. LINGUAL ASPECT a. trapezoidal shaped lingual fossa b. cingulum well developed and occupies cervical half of the crown c. crown outline trapezoidal

4. MESIAL ASPECT a. contact area at incisal 1/3 and centered faciolingually b. curvature of cervical line toward incisal greatest of any tooth c. crown outline triangular

37

F L

5. DISTAL ASPECT a. distal contact area at junction of middle and incisal third b. crown outline triangular

Notes: 1. Hutchinson’s Incisor: An anomaly associated with congenital syphilis

resulting in the crown portion of this tooth being “screwdriver” shaped. 2. Dimensions: CI (10.5 mm) > MD ( 8.5 mm) > FL (7.0 mm)

3. Facial surface is straight to slightly convex from cervical ridge to the incisal ridge

4. MI lineangle is sharper than the DI lineangle 5. Root is conical, straight and generally round on cross section. It may

however show a slight convergence toward the lingual, with the mesial dimension being wider faciolingually than the distal.

6. Curvature of cervical line toward the incisal on the mesial surface is the

greatest cervical line curvature of any tooth

7. Cervical line height of curvature on the facial surface canted very slightly toward the distal.

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DENTAL ANATOMY PERMANENT MAXILLARY LATERAL INCISOR

1. FACIAL ASPECT - MAXILLARY LATERAL INCISOR

a. Crown length is 1.0 -1.5 mm shorter than the maxillary central incisor. Crown width is 2.0 mm less than the maxillary central incisor. This gives impression that the maxillary lateral incisor is relatively long and narrow.

b. Crown outline is trapezoidal with the shorter parallel side at the cervix.

c. Incisal edge is relatively more rounded (curved) than the maxillary central incisor.

d. Both mesial and distal incisal line angles are said to be rounded and each is more rounded than the corresponding incisal line angle of the maxillary central incisor. The distoincisal line angel is more rounded than the mesioincisal angle.

e. The mesial proximal contact is at the level of the junction of the incisal and middle thirds of the crown.

f. The distal contact is at a level near the middle of the middle 1/3 of the crown.

g. The curvature of the cervical line incisally is elliptical and not as broad as that of the maxillary central incisor. The highest point of the curve is likely to be slightly distal to mesiodistal bisector of the crown.

h. The facial surface is said to be convex in all directions. i. The root converges evenly toward the apex for the

cervical two thirds of its length. There is usually a characteristic curve of the root toward the distal in its apical third.

M D

39

2. LINGUAL ASPECT - MAXILLARY LATERAL INCISOR

a. The lingual outline of the crown and root is the reverse of the labial outline.

b. The lingual fossa is relatively deep, triangular in shape and also “cup-shaped.” It occupies the incisal two thirds of the lingual surface of the crown.

c. The anatomical features serving as boundaries for the fossa are the same as those for the maxillary central incisor; however, the cingulum of the maxillary lateral incisor is limited to the cervical 1/3 of the crown and the mesial and distal marginal ridges form a “V” as they meld into the cingulum. There is often a very deep depression or even a pit, deep in the fossa behind the cingulum at the point of the “V”.

d. Occasionally there will be a developmental groove extending out of the lingual fossa between a marginal ridge and the cingulum, usually on the distal side of the cingulum. This groove may be quite deep and mayeven extend across the cementoenamel junction onto the root. It is termed the linguogingival groove and is unique to the maxillary lateral incisor.

3. MESIAL ASPECT - MAXILLARY LATERAL INCISOR

a. Greatest curvature of both the facial and lingual crown outlines is in the cervical 1/3 and each is identified as a cervical ridge.

b. Incisal ridge is in line with mid-point of the faciolingualdiameter.

c. Facial crown outline is convex from facial cervical ridgecrest to incisal ridge.

d. Lingual crown outline is slightly concave from lingual cervical ridge to the incisal ridge.

e. Curve of the cervical line toward the incisal is greater on the mesial surface than on the distal surface. It extends for 1/3 of the crown length but not as great of a distance as on the maxillary central incisor since the lateral incisor has a shorter crown length.

f. Apex of the root is usually facial to the faciolingual long axis bisector.

g. If there is any evidence of a root depression, it will be slight.

D M

L F

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5. INCISAL ASPECT - MAXILLARY LATERAL INCISOR

a. Crown is wider mesiodistally than it is faciolingually by only 0.5 mm (6.5 mm vs 6.0 mm).

b. Incisal ridge crosses approximately midway between the facial and lingual outline; however, it usually shows some curvature with the convexity toward the facial.

c. The facial outline is more continuously convex than that of the maxillary central incisor and the mesiofacial and distofacial line angles are more rounded (less prominent).

d. The crown outline converges sharply toward the lingual. The crest of the lingual outline of the cingulum will be slightly to the distal of the mesiodistal bisector (all cinguli incline or point slightly toward the distal).

4. DISTAL ASPECT - MAXILLARY LATERAL INCISOR

a. As noted, the incisal ridge and root apex will not be in line with one another, but the incisal ridge is centered faciolingually.

b. Facial outline of root will be straighter and shorter than the lingual outline when measured from cervical line to apex of root.

c. Cervical line curves for a shorter distance incisally on the distal surface.

F L

M D

41

DENTAL ANATOMY PRINCIPLE CHARACTERISTICS OF A

PERMANENT MAXILLARY LEFT LATERAL INCISOR

1. INCISAL ASPECT a. Incisal ridge centered faciolingually b. Crown outline demonstrates significant lingual conversion

2. FACIAL ASPECT a. Features of the maxillary lateral incisor are more rounded than those of the

maxillary central incisor b. Root length can be as long or longer than the maxillary central incisor c. CI crown length (9.0 mm) less than CI crown length of maxillary central

incisor (10.5 mm)

3. LINGUAL ASPECT a. Triangular shaped lingual fossa b. Lingual pit often found at apex of triangular fossa c. Linguogingival developmental groove

L F

4. MESIAL ASPECT a. Mesial contact area at junction of the middle & incisal thirds and

centered faciolingually b. Crown outline triangular

42

Anomalies: (The maxillary lateral incisor is the permanent tooth most likely to have anomalies)

1. Often missing (anodontia) 2. Microdontia (abnormally small teeth) 3. Peg lateral 4. Dens in dente 5. Supernumerary (teeth in addition to normal number in the dentition)

Notes:

1. Root: may be more ovoid in cross section than the root of the maxillary central incisor but it is still comparatively round

2. Root often has a distal curvature in the apical ⅓ 3. Root length is generally the same as the maxillary central incisor (13.0

mm) or can be longer. 4. Crown size: CI (9.0 mm) > MD (6.5 mm) > FL (6.0 mm) 5. Has more distinct lingual anatomy than the maxillary central incisor 6. Linguogingival groove extends from lingual pit gingivally, usually in a

distal direction. Can cross the CEJ onto the root surface and is prone to decay because hygiene is difficult.

7. Because of its lingual pit, the maxillary lateral incisor is the most likely of all the incisors to require a lingual restoration

8. Mamelons (if present) are not as prominent as those of the maxillary central incisor

F L

5. DISTAL ASPECT a. Contact area located in middle third and centered faciolingually b. Crown outline triangular

PERMANENT MAXILLARY INCISORS

I. Permanent Incisors (General)

Class Traits (Permanent incisors)

1. The incisal two-thirds of the crown appears flattened or compressed faciolingually, providing a long horizontal “biting” edge or margin.

2. Distinct and rounded protuberances termed “mamelons” representing developmental lobes surmount the incisal margins of all newly erupted incisors.

3. The marginal ridges of all incisors are located on the mesial and distal borders of the lingual surfaces.

II. Permanent Maxillary Incisors

Arch Traits (Permanent Maxillary Incisors)

1. Maxillary incisors are wider than the corresponding mandibular incisors.

2. The central incisor is larger than the lateral incisor. 3. Lingual morphology (marginal ridges and cinguli) is more

prominent on maxillary incisors than on mandibular incisors. 4. Lingual fossae are deeper on maxillary incisors because

marginal and incisal ridges are more prominent. 5. Roots are rounded or triangular in cross section with equal

faciolingual and mesiodistal widths. 6. Facial surfaces are more rounded when viewed from the incisal

aspect. 7. Crowns are wider mesiodistally than faciolingually.

43

44

B. Type Traits (Permanent maxillary incisors)

CENTRAL LATERAL 1. Facial Aspect

a. Mesiodistally b. Mesioincisal

line angle c. Distoincisal line

angle d. Mesial profile e. Distal profile f. Mesial contact a. Facial surface b. Distal contact

Wide Sharp (90 degrees) Slightly rounded Straight Rounded Incisal third Relatively flat Junction of incisal and middle thirds

Narrower than central Slightly rounded Distinctly rounded Slightly rounded Highly rounded Junction of incisal and middle thirds Rounded Middle third

2. Lingual aspect a. Marginal ridges

and cingulum b. Lingual fossa

Moderately pronounced Trapezoidal; Moderately deep

More prominent Triangular; Deep

3. Mesial aspect a. Cementoenamel

junction b. Contact area c. Cingulum

Moderately curved Within incisal third Moderately convex

Less curved Junction of incisal and middle thirds Convex

4. Incisal aspect a. Outline b. Labial surface c. Lobes d. Mesiofacial and

distofacial line angles

Triangular Slightly convex Visible facially Prominent

Ovoid Highly convex Slightly visible to absent Rounded

45

Trauma to Maxillary Incisors: People in general and children in particular are subject to accidents that damage their teeth. The most likely teeth to be damaged are the maxillary central incisors. Due to their position in the mouth and their conical roots, they often fall victim to blunt traumatic injuries. An incisor in labioversion is particularly susceptible to this sort of injury. If an injury occurs: 75% will involve only the enamel and are usually easily repaired with a bonded composite restoration or by simply smoothing the enamel. 24% involve the dentin and enamel and are repaired with a bonded composite restoration. 1% will involve the pulp of the tooth and require endodontic (root canal) treatment and the placement of a crown. Avulsion: The total dislodgement of the tooth from its socket. Usually such a tooth can be successfully re-implanted in the socket if certain procedures are followed. Most importantly, successful re-implantation of an avulsed tooth is time dependent. < 30 minutes = 90% success rate 30 – 90 minutes = 40% success rate > 90 minutes = 7% success rate How to Re-Implant an avulsed Tooth:

1. Reassure the child and the occasionally frantic parent. 2. Wash the tooth gently with water to remove any loose debris. Do not

scrub the tooth. Remnants of the periodontal ligament and the cementum should not be disturbed.

3. Have the parent replace the tooth in the socket if possible. 4. Have the patient brought to the dental office immediately. A dentist can

stabilize the tooth by splinting (affixing it to a stable adjacent tooth or teeth).

If the tooth cannot be re-implanted prior to arrival at the dental office, the tooth should be kept moist in milk, water, or saliva (last choice). The tooth will require root canal therapy once it is stabilized.

46

PERMANENT MANDIBULAR CENTRAL INCISOR

1. FACIAL ASPECT - MANDIBULAR CENTRAL INCISOR

a. Crown outline trapezoidal with longer parallel side at incisal edge. b. Incisal edge straight and at right angle to (perpendicular to) the

long axis line of the tooth. c. Mesial and distal incisal line angles are both said to be sharp

almost 90° angles. However, the distal incisal line angle slightly more rounded than the mesial incisal line angle.

d. The mesial and distal proximal contacts are at the same level and are within the incisal 1/3 of the crown (after incisal wear the contacts may be very near the incisal edge).

e. The incisal 1/3 of the crown surface is relatively flat. The cervical two thirds of the surface is convex.

f. The mesial outline may be slightly straighter than the distal outline.

g. The crest of the curve of the cervical line may be ever so slightly to the distal of the mesiodistal long axis bisector.

h. However when viewing the facial aspect of this crown, it is considered to be bilaterally symmetrical.

i. The root converges evenly to a relatively pointed apex. The apex may be slightly to the distal of the mesiodistal long axis bisector but it will rarely if ever be curved to any great extent.

2. LINGUAL ASPECT - MANDIBULAR CENTRAL INCISOR

a. The lingual outline is the reverse of the facial outline. b. The anatomical features found on the lingual surfaces of all

incisors (marginal ridges and cinguli) are present but relatively muted and not conspicuous on mandibular incisors.

c. The lingual fossa is trapezoidal in shape, will be very shallow and limited to the incisal 1/3 of the crown.

d. The cingulum will be smoothly rounded and not as prominent as the cinguli of the maxillary incisors.

M D

D M

47

3. MESIAL ASPECT - MANDIBULAR CENTRAL INCISOR

a. The incisal ridge will be lingual to the faciolingual long axis bisector.

b. The enamel on the lingual surface will extend apically about 0.5 mm farther than it does on the facial. This makes the measurement of the anatomical crown 0.5 mm greater on the lingual surface than on the facial surface.

c. The crests of the cervical ridges (greatest curvatures) will not be at the same level facially and lingually (the crests of these ridges are about 1 mm incisal to the cervical line).

d. Cervical ridges are not as well developed on mandibular anterior teeth. Their crests extend beyond the labiolingual diameter of the root at the cervix less than the 0.5 mm. When compared to most other permanent teeth, this is quite small.

e. The cervical line curves incisally more on the mesial surface than on the distal surface.

f. The root converges apically, evenly toward a relatively blunt (rounded) root end.

g. A broad longitudinal root depression is usually found for most of the length of the root.

4. DISTAL ASPECT - MANDIBULAR CENTRAL INCISOR

a. The distal outline is a reverse image of the mesial outline. b. It should be noted that in spite of the fact that the incisal

ridge is lingually placed relative to the faciolingual long axis bisector, the proximal contact areas are at a level cervical to the incisal ridge and are near the mid-point of the tooth faciolingually.

c. The cervical line curves incisally for a relatively shorter distance on the distal than on the mesial surface.

d. The broad root depression may be deeper on the distal surface of the root than on its mesial. The apex of the root will be even with the faciolingual long axis bisector.

L F

F L

48

NOTES:

1. Incisal ridge slightly lingual of the faciolingual bisector 2. The lingual fossa is trapezoidal in shape 3. When compared to the maxillary central incisor, the tooth is much narrower

with the crown having more squared incisal line angles. The mandibular central incisor is the narrowest (M-D) of all teeth

4. Crown is considered to be bilaterally symmetrical 5. Mesial & distal proximal contacts are high on the incisal third of the crown 6. The root is wider in a faciolingual dimension and is narrow mesiodistally 7. The root has developmental depressions on both the mesial and distal

surfaces and a tendency for two canals 8. May on rare occasion have two roots

5. INCISAL ASPECT - MANDIBULAR CENTRAL INCISOR

a. The faciolingual diameter is greater than the mesiodistal width.

b. The greatest curvature mesially and distally (proximal contact areas) are equidistant between the facial and lingual outlines.

c. The incisal ridge runs straight across the tooth mesiodistally parallel to but slightly lingual to the faciolingual bisector of the crown.

d. Mesiofacial and distofacial line angles are more distinct (less rounded) than those of a maxillary lateral incisor because of the relative flatness of the incisal 1/3 of the facial surface.

e. The crest of the cingulum lingually is usually slightly to the distal of the mesiodistal bisector of the crown.

f. In spite of this, the outline of the mandibular central incisor crown from the incisal view is said to be bilaterally symmetrical.

D M

49

PERMANENT MANDIBULAR LATERAL INCISOR

M D

1. FACIAL ASPECT- MANDIBULAR LATERAL INCISOR

a. The mandibular lateral incisor is larger than the mandibular central incisor in all dimensions.

b. The incisal edge is straight but it may appear slanted toward the distal.

c. The mesial incisal line angle is said to be a sharp 90° angle; the distal incisal line angle usually appears a little more rounded.

d. Proximal contacts are both within the incisal 1/3 of the crown and are considered to be at essentially the same level.

e. There is often more curvature in the distal crown outline; therefore, the crown is not considered symmetrical from the facial view.

f. The crest of the gingival curvature of the cervical line will be slightly distal to the mesiodistal long axis bisector.

g. The root tapers to a pointed apex. It may curve slightly to the distal or remain straight.

2. LINGUAL ASPECT- MANDIBULAR LATERAL INCISOR

a. The lingual outline is the reverse of the labial outline. b. Anatomical features are not as prominent as they are on

maxillary incisors. c. The lingual fossa is trapezoidal in shape, shallow and limited

to the incisal 1/3 of the crown. d. The cingulum is smoothly rounded and not well delineated.

D M

50

4. DISTAL ASPECT- MANDIBULAR LATERAL INCISOR

a. The distal outline of this tooth resembles the distal of the mandibular central incisor. It is not a reverse image of the mesial view of the mandibular lateral incisor. From the distal aspect the mesial marginal ridge cannot be seen protruding to the lingual as it is hidden by the outline of the distal marginal ridge.

b. The cervical line curves less incisally than on the mesial. c. The root outline and root depression are similar to that of

the distal surface of the root of a mandibular central incisor.d. The apex of the root will be in line with the faciolingual

long axis bisector.

L F

3. MESIAL ASPECT- MANDIBULAR LATERAL INCISOR

a. The incisal ridge will be lingual to the faciolingual long axis bisector of the tooth.

b. When measured, the anatomical crown is longer from the incisal ridge to the cervical line on the lingual surface. Enamel extends apically 0.5 mm more on the lingual than onthe facial surface.

c. The crest of the facial cervical ridge will be at a higher level incisally than the crest of the lingual cervical ridge.

d. The height of contour of the crown beyond the root facially and lingually will be less than 0.5 mm on either surface.

e. The cervical line curves incisally to a higher level on the mesial surface than on the distal.

f. Since the crown of this tooth is slightly “twisted” on its root and the distal end of the incisal ridge is more inclined to the lingual, a part of the distal marginal ridge can be seen beyond the lingual outline of the mesial marginal ridge. This is a distinctive characteristic of this tooth from the mesial view.

g. The mesial surface of the root will be similar in outline to that of the mandibular central incisor. A broad root depression will exist for most of the root length.

F L

DMR

51

NOTES:

1. Of all of the incisors, the mandibular lateral incisor has the strongest tendency to have two canals, one facial and one lingual.

2. Also most likely incisor to have two roots 3. Lingual fossa shallow and trapezoidal in shape 4. Both mesial and distal proximal contacts at the incisal 1/3 of the crown 5. Tooth is not bilaterally symmetrical 6. Incisal ridge lingual to the faciolingual bisector 7. Distal portion of the crown more inclined toward the lingual giving it a “twisted”

appearance. This characteristic is best seen from either a mesial or incisal view. 8. Root is ovoid, wider faciolingually and narrower mesiodistally 9. Larger tooth than the mandibular central incisor

5. INCISAL ASPECT- MANDIBULAR LATERAL INCISOR

a. The faciolingual measurement is greater than the mesiodistal. b. The mesial contact area is centered faciolingually but the distal

proximal contact will be slightly to the lingual of the faciolingual bisector.

c. The incisal ridge will be lingual to the faciolingual bisector of the crown outline in its entirety; however, the distal end of the ridge will be more toward the lingual than the mesial end.

d. The incisal ridge will be relatively straight but it is not straight across the tooth mesiodistally. It slants to the lingual at its distalend and is not parallel to the faciolingual bisector.

e. The crest of the cingulum lingually will be slightly distal to the mesiodistal bisector.

f. The crown of the mandibular lateral incisor from the incisal view is said to look “twisted” or “rotated” on its axis, not at all symmetrical.

D M

52

DENTAL ANATOMY PRINCIPAL CHARACTERISTICS OF THE

PERMANENT MANDIBULAR LATERAL INCISOR

1. INCISAL ASPECT a. Crown “twisted” (distal portion more lingual than mesial portion) b. FL (6.5 mm) > MD (5.5 mm) c. Incisal ridge lingual to the faciolingual bisector

2. FACIAL ASPECT a. Wider mesiodistally (5.5 mm) than the mandibular central

incisor (5.0 mm) b. MI line angle sharp; DI line angle more rounded

3. LINGUAL ASPECT a. Anatomical features not as prominent as maxillary incisors b. Lingual fossa shallow and trapezoidal in shape c. Cingulum smoothly rounded and not well defined

4. MESIAL ASPECT a. Because of “twisted crown,” the DMR is seen from this view b. Incisal ridge lingual to the faciolingual bisector c. DMR visible from mesial aspect

L F

53

5. DISTAL ASPECT a. Cervical ridges extend facially & lingually only 0.5 mm beyond the cervical line b. Incisal ridge is lingual to the faciolingual long axis bisector

F L

Additional Notes:

54

PERMANENT MAXILLARY CANINE

1. FACIAL ASPECT - MAXILLARY CANINE

a. Although canines have a cusp that keeps the facial outline from being a true trapezoid, the outline is still said to be a trapezoid with the shorter parallel side at the cervix.

b. The tip of the cusp may be centered or it may be slightly to the mesial of the mesiodistal long axis bisector.

c. In either case, the mesial cuspal ridge will be shorter than the distal cuspal ridge because there is a difference in the level of the mesial and distal proximal contact areas.

d. The mesial contact is said to be at the level of the junction ofthe incisal and middle 1/3 of the crown.

e. The distal contact is usually near the middle of the middle 1/3 of the crown.

f. The mesial crown outline from the contact to the cervical line is slightly convex.

g. Although the distal outline in the contact area is definitely convex (almost semicircular), there is a concave segment between the distal contact area and the cervical line.

h. The crest of the arc of the cervical line apically will usually be slightly distal to the mesiodistal long axis bisector.

i. The crown converges evenly (at the same rate, mesially and distally) from the contact areas to the cervical line. This gives the feeling that the crown is “balanced” under its root (this will contrast with the description of a mandibular canine).

j. The crest of the facial ridge (greatest facial curvature of this surface in an incisocervical direction) will curve slightly toward the mesial. The curvature mesially will be at the mid-point of the crest.

k. The crown surface mesial to the crest of the facial ridge will be convex in all respects.

l. The crown surface distal to the crest of the labial ridge is convex in the incisal ½; however, the distocervical quadrantof the surface is slightly concave. The concavity is manifest in the distal outline of the crown.

m. There may be some evidence of vertical developmental depressions between lobes particularly between the middle facial and the distal lobes.

n. The root is conical in form. It is the longest of all roots of human teeth. The root may remain straight or it may curve in its apical 1/3, usually toward the distal.

M D

55

2. LINGUAL ASPECT - MAXILLARY CANINE

a. The lingual outline will be the reverse of the facial outline.

b. Anatomical features on the maxillary canine are well developed.

c. There are two lingual fossae. They are termed the “mesiolingual fossa” and the “distolingual fossa”.

d. The two lingual fossae are separated by the lingual ridge which connects the cusp tip and the cingulum. The crest of this ridge curves with the mid-part of the curve slightly mesial to the mesiodistal long axis bisector. This makes the distolingual fossa a little larger than the narrower mesiolingual fossa.

e. The cingulum is smooth but well developed and occupies the cervical ⅓ of the lingual surface.

f. The crest of the cingulum lingually and the crest of the curve of the cervical line cervically are both slightly distal to the mesiodistal long axis bisector.

g. The root tapers lingually, i.e. the ligual root surface is more narrow than the facial.

3. MESIAL ASPECT - MAXILLARY CANINE

a. The outline of the crown from a mesial aspect is triangular.

b. The tip of the cusp may be centered faciolingually but it is usually slightly facial to the faciolingual long axis bisector. The cusp tip is never lingual.

c. The facial and lingual cervical ridges are well developed and their crests oppose one another at the same level.

d. The facial outline between the cervical ridge and cusp tip is smoothly convex.

e. The lingual outline will be that of the convex cingulum and the crest of the lingual ridge which is slightly concave. This is sometimes referred to as an “S” shapedlingual outline.

f. The outline of the mesial marginal ridge will follow somewhat the same curvature but a little to the facial of the lingual outline.

g. The cervical line on the mesial aspect will not extend as far incisally as on the incisors, but will extend incisally more on the mesial surface than on the distal surface.

D M

L F

56

g. The root from the mesial aspect remains broad and converges gradually to a relatively blunt tip that is usually facial to the faciolingual long axis bisector. Note that both the apex of the root and the cusp tip are usually facial to this line and therefore are more or less in line with one another vertically.

h. A shallow developmental depression is normally found for part of the root length.

4. DISTAL ASPECT - MAXILLARY CANINE

a. The outline is the reverse of the mesial outline. b. The distal marginal ridge crest is farther to the

lingual and its crest will more closely follow the lingual outline of the lingual ridge.

c. The cervical line curves less incisally on the distal

surface than it does on the mesial surface. d. The root depression is likely to be deeper than the

depression on the mesial surface of the root. F L

57

d. The facial outline is full and rounded in its mesial and middle thirds but there is definitely a concave area in the outline where the middle facial and distal lobes have joined.

e. The lingual outline is also fuller and continuously

convex from the mesial contact area to the crest of the cingulum than it is between the cingulum and the distal contact area. The relative thinness of the distal lobe causes a concavity in the lingual outline of this area. Therefore, the crown from this view looks wider faciolingually in its mesial half.

f. The crest of the lingual outline will be slightly distal

to the mesiodistal bisector.

5. INCISAL ASPECT - MAXILLARY CANINE

a. The incisal outline is described as diamond shaped. It measures wider faciolingually than mesiodistally. (Note that this differs from maxillary incisors).

b. From the incisal view, the cusp tip will usually be

slightly facial to the faciolingual bisector of the crown and slightly mesial to the mesiodistal bisector. However, it may be centered within the crown outline.

c. The cuspal ridges are generally in line with one another

across the tooth mesiodistally; but not necessarily straight across the tooth. The distal end of the distal cuspal ridge is likely to be a little lingual to the mesial end of the mesial cuspal ridge. (Both cuspal ridges comprise the incisal ridge.) There is some compensation in this tooth form that contributes to the curvature of the maxillary dental arch. The maxillary arch presents a wider arch than does the mandibular arch; therefore, the curving effect is less dramatic in the maxillary canine than that observed in the mandibular canine and lateral incisor.

M D

58

PRINCIPLE CHARACTERISTICS OF A PERMANENT MAXILLARY CANINE

1. INCISAL ASPECT a. diamond shaped b. cusp tip centered or slightly facial of FL bisector c. cingulum offset to the distal d. wider FL (8.0 mm) than MD (7.5 mm)

2. FACIAL ASPECT a. Cusp tip will be centered or slightly mesial to the MD long axis bisector b. Mesial cuspal ridge shorter than the distal cuspal ridge due to the relative

positioning of the proximal contacts c. The crown outline cervical to the mesial contact area is convex d. The crown outline cervical to the distal contact area is concave e. Root form is conical f. Longest root of any tooth (17.0 mm) g. Mesial contact area: Junction of middle & incisal thirds h. Distal contact area: Middle ⅓ (area of greatest convexity)

3. LINGUAL ASPECT a. Prominent mesial and distal marginal ridges b. Prominent lingual ridge and cingulum c. Mesiolingual (smaller) and distolingual (larger) fossae

59

NOTES:

1. Due to its facial positioning, the maxillary canine gives rise to “canine eminence” or prominence in the maxillary dental arch.

2. The canines are considered to be transitional teeth between anterior and posterior teeth and contain features of both.

3. Canines are extremely important teeth in esthetics and occlusal function 4. Of all the teeth (maxillary & mandibular), the maxillary canine has the longest root 5. The maxillary canine crown has asymmetrical anatomy. The distal portion of the

crown is not as well developed as the mesial portion. 6. The maxillary canine is the widest (faciolingually) of all the anterior teeth (8.0 mm). 7. The maxillary canine has the longest root of any tooth (17.0 mm) 8. The middle-facial lobe is the most developed of all the lobes and gives rise to the

facial ridge. 9. From a proximal viewpoint, the cusp tip of the maxillary canine is lined up with the

root tip. It may be centered or slightly facial of the faciolingual long axis bisector. It is never lingual.

10. The cingulum is well developed and smooth.

L F

4. MESIAL ASPECT a. Crown outline triangular b. Cusp tip centered or slightly facial (never lingual) c. Facial & Lingual cervical ridges at the same level d. Facial outline smoothly convex e. Lingual outline extending from the convex cingulum and

slightly concave crest of the lingual ridge is said to resemble an “S”

f. Cusp tip and root apex are aligned g. Shallow developmental root depression h. Cervical line slumps significantly toward the incisal

F L

5. DISTAL ASPECT a. Distal marginal ridge more lingual than mesial marginal ridge b. Distal marginal ridge follows the outline of the lingual ridge c. Root depression deeper than that found on the mesial surface d. Cervical line “slump” is not as severe

60

PERMANENT MANDIBULAR CANINE

1. FACIAL ASPECT - MANDIBULAR CANINE

a. The mandibular canine is narrower mesio-distally and the crown is longer (inciso-gingivally) than that of the maxillary canine.

b. The mesial proximal contact is at the incisal 1/3 and the distal proximal contact is at the middle 1/3 of the crown.

c. The average root length of the mandibular canine is 16.0 mm which is only 1.0 mm shorter than that of the maxillary canine (17.0 mm).

d. The cusp tip will appear less pointed than the cusp tip of the maxillary canine. The proximal contact areas are nearer the incisal outline and the cuspal ridges meet at a wide obtuse angle. The tip will be mesial to the mesiodistal long axis bisector and the mesial cuspal ridge will always be shorter than the distal cuspal ridge.

e. The mesial contact area is in the incisal 1/3 of the crown. The distal contact is within the middle 1/3 of the crown but is more incisally placed than is the distal contact of the maxillary canine.

f. The mesial outline of the crown, from contact area to cervical line is straight. There is little or no change in direction between the crown and root outlines.

g. The distal outline of the crown, from the contact area to the cervical line, reflects a concavity in the tooth surface. There is a change of direction between the crown and root outlines.

h. The cervical outline of the crown is described as the arc of a “semicircle”. The cervical crest of thearc will fall slightly distal to the mesiodistal long axis bisector.

i. The crown does not look balanced over its root but rather looks “tipped” to the distal.

M D

61

j. As was true for the maxillary canine, the crest of the facial ridge curves slightly so that the middle segment of the curve is slightly mesial to the mesiodistal long axis bisector.

k. The crown surface mesial to this crest is convex. The crown surface distal to the crest of the facial ridge is convex in its incisal ½ but slightly concave in its cervical ½. (The morphology of the facial surface of the maxillary canine was similarly described).

l. The root outline tapers evenly from the cervical line for 2/3 of the root length and usually curves distally in its apical 1/3. The root may curve mesially or remain straight. Occasionally this root may bifurcate into a facial and lingual root. This is the only anterior tooth that does bifurcate often enough that the fact is noted in textbooks.

2. LINGUAL ASPECT - MANDIBULAR CANINE

a. The lingual outline will be the reverse of the labial outline.

b. As was true when comparing the lingual anatomy of maxillary and mandibular incisors, it is noted that the anatomical features of mandibular canines (while present and identifiable) are more poorly developed when compared to those of the maxillary canine. The mesial and distal lingual fossae are shallow. The borders of each fossa are their respective marginal ridges and cuspal ridges, the lingual ridge and the cingulum.

c. The crest of the cervical line apically will be distal to the mesiodistal long axis bisector.

D M

62

3. MESIAL ASPECT - MANDIBULAR CANINE

a. As is true of the mandibular incisors, the incisal ridge (mesial and distal cuspal ridges referred to collectively) will be lingual to the faciolingual long axis bisector.

b. The cusp tip of the mandibular canine is lingual to the faciolingual long axis bisector.

c. Unlike the mandibular incisors, the facial and lingual extent of the enamel apically is at the same level and the crests of the facial and lingual cervical ridges are also at the same level across the tooth surface.

d. Like the mandibular incisors, the apex of the rootis in line with the faciolingual long axis bisector.

e. The mesial contact area is centered faciolingually and within the incisal 1/3 of the crown.

f. The facial outline from the facial cervical ridge to the cusp tip is slightly convex. The lingual outline from the cingulum to the lingual roll-over of the cusp tip is slightly concave.

g. A separate outline marking the crest of the mesial marginal ridge may also be seen from the mesial aspect.

h. The cervical line curves incisally more on the mesial surface than on the distal but not as much in respect to the total crown length as is seen on incisors.

i. The root outline usually tapers evenly to a relatively pointed apex that is centered faciolingually. As previously noted, the mandibular canine is the anterior tooth most likely to have a bifurcated root. There may be a true bifurcation into a facial and lingual root for as much as ½ the root length; or there may be a deep mesial and distal root depression in the apical ½ of the root suggesting two root canals and two apical foramina.

L F

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4. DISTAL ASPECT - MANDIBULAR CANINE

a. The distal outline will be the reverse of the mesial outline.

b. The distal contact area will be just cervical to the junction of the incisal and middle thirds of the crown.

c. The cervical line curves less toward the incisal than it did on the mesial surface.

d. The morphological characteristics of the root surface will be similar to the mesial surface of the same root.

5. INCISAL ASPECT - MANDIBULAR CANINE

a. The incisal outline measures wider faciolingually than it does mesiodistally. The general shape of the outline is similar to that of the maxillary canine, including the slight facial concavity at the junction of the middle facial and distal lobes.

b. The lingual crest of the outline of the cingulum will be slightly distal to the mesiodistal bisector.

c. The primary distinguishing characteristic of a mandibular canine from the incisal view is the location of the cusp tip and cuspal ridges. The cusp tip will always be lingual to the faciolingual bisector of the tooth.

d. As is true of the maxillary canine, the distal end of the distal cuspal ridge may be a little more lingual than the mesial end of the mesial cuspal ridge. Both cuspal ridges combine to form the incisal ridge. Most of the curve in the mandibular arch is compensated for in the directional curve of the incisal ridge of the lateral incisor; however, in some instances there will be additional evidence of compensation in the mandibular canine as well.

F L

D M

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PRINCIPLE CHARACTERISTICS OF A PERMANENT MANDIBULAR LEFT CANINE

D M

1. INCISAL ASPECT a. Narrower mesiodistally (7.0 mm) than the maxillary canine

(7.5 mm) b. Wider FL (7.5 mm) than MD (7.0 mm) c. Asymetrical diamond outline d. Cusp tip and ridges lingual to the faciolingual bisector e. Cusp tip slightly mesial to the mesiodistal bisector

M D

2. FACIAL ASPECT a. Crown is longer (IC) (11.0 mm) than the crown of the maxillary

canine (10.0 mm) b. IC crown length (11.0 mm) longest of any tooth c. Mesial outline straight, distal outline concave d. Cervical outline “arc of a semicircle” e. Crown does not look balanced over the root but tipped to the distalf. Mesial cuspal ridge shorter than the distal cuspal ridge g. Mesial contact area: Incisal ⅓ h. Distal contact area: Middle ⅓

D M

3. LINGUAL ASPECT a. Anatomical features less prominent than those of the maxillary canine b. ML & DL fossae are separated by the lingual ridge

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F L

4. MESIAL ASPECT a. Cusp tip and ridges lingual to the faciolingual bisector b. Prominent developmental root depression. Anterior tooth

most likely to have two roots, facial & lingual c. Mesial contact area centered faciolingually within the

incisal third of the crown

L

F

5. DISTAL ASPECT a. Distal contact area slightly cervical to the junction of the

incisal and middle thirds of the crown b. Prominent developmental root depression

NOTES: 1. Mandibular canine crown is slightly smaller M-D & F-L than the crown of the

maxillary canine but is longer IC. 2. When viewed from the facial aspect, cervical line is semicircular in appearance 3. Mesial cuspal ridge significantly shorter than the distal cuspal ridge 4. Mesial contour straight and continuous between crown and root, distal contour

presents a concavity in the cervical area 5. MF line angle more angular than DF line angle which is more rounded 6. Cusp tip lingual to the faciolingual long axis bisector 7. Mandibular canine is the anterior tooth most likely to have a root bifurcation one

facial & one lingual).

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PERMANENT CANINES (aka Cuspids)

I. Permanent Canines (General)

Class Traits:

1. Canines are the only teeth in the dentition possessing a single conical cusp.

2. Canines have the longest single root of all the teeth. 3. Canines are the only cusped teeth that feature a functional

lingual surface. Typically, the functional surface of a tooth is the occlusal (posterior) or the incisal (anterior) surface.

II. Permanent Maxillary Canines

1. Overall, the crown of the maxillary canine is larger than the mandibular canine (of the same dentition) however the actual crown length of the mandibular canine (measured incisocervically) is slightly longer.

2. The mesial and distal marginal ridges converge markedly toward the cervix.

3. The incisal portion of the crown (as measured from the contact areas to the tip of the cusp) occupies at least one-third of the crown height (often as much as one-half).

4. The mesial and distal marginal ridges, the lingual ridge, and the cingulum are more prominent than those of the mandibular canine.

5. A lingual pit and/or grooves are a common feature. 6. The faciolingual diameter of the crown near the cervix is greater

than that of the mandibular canine. 7. There is a marked asymmetry of the mesial and distal halves of

the crown when viewed from the incisal aspect. 8. The crown appears to be more centered over the root. 9. The cusp tip is centered over the root tip or is slightly facial to

the faciolingual long axis bisector. It is never lingual to it.

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III. Permanent Mandibular Canines

1. The crown is slightly smaller than the maxillary canine. 2. The mesial outline (when viewed from the facial aspect) is

straight from the contact area to the cervical line. There is little or no change in direction between the crown and root outlines.

3. The distal outline of the crown is concave from the contact area to the cervical line. There is a change in direction between the crown and root outlines.

4. The crown appears tipped off center toward the distal. 5. The incisal portion of the crown occupies only the incisal one-

fourth or one-fifth of the crown, giving the tooth a long, narrow appearance when compared to the maxillary canine.

6. The entire lingual surface is flatter than the maxillary canine, with much less prominence of marginal ridges, lingual ridge, and cingulum.

7. There are no lingual pits or grooves. 8. The faciolingual diameter of the crown near the cervix is less

than that of the maxillary canine. 9. The mesial and distal halves of the crown, when viewed from

the incisal aspect, are more symmetrical than the maxillary canine.

10. The cusp tip is lingual to the faciolingual long axis bisector. NOTES:

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MAXILLARY FIRST PREMOLAR (aka maxillary 1st bicuspid)

1. FACIAL (BUCCAL) ASPECT - MAXILLARY FIRST PREMOLAR

a. Facial outline of the crown is a trapezoid with the shorter parallel side at the cervix.

b. The tooth is broad shouldered when viewed from this aspect with markedly convex mesial and distal contours.

c. The cusp tip is relatively pointed and will be slightly distal to the mesiodistal long axis bisector. (This is a distinctive characteristic since this is the only permanent tooth where the mesial cuspal ridge of the facial cusp is longer than the distal cuspal ridge).

d. The mesial proximal contact is slightly more cervically placed than the distal proximal contact. (This is a characteristic of both maxillary and mandibular first premolars and would be expected since the mesial contact meets the distal contact of a canine and both maxillary and mandibular canines have their distal contact areas in the middle 1/3 of the crown incisogingivally).

e. The mesial outline of the crown between the mesial contact area and the cervical line is slightly concave. This is principally due to the developmental root depression on the mesial surface that extends over the CEJ onto the crown surface better described from the mesial aspect. Although not visible from the facial aspect, this outline is said by one text to be a mirror image of the distal contour of the adjacent canine.

f. The distal outline of the crown between the contact area and the cervical line is slightly convex.

g. The apical crest of curvature of the cervical line on premolar crowns will usually be centered but may be slightly distal to the mesiodistal long axis bisector.

h. The root of this tooth is usually bifurcated into a facial and a lingual root. Since the facial root is usually wider than the lingual root, the lingual root will not always be visible from the facial aspect. However, dental charts depicting a drawing of this tooth from a facial view will usually show the apices of both roots on the drawing.

i. The apices of both the facial and lingual roots will usually be slightly distal to the mesiodistal long axis bisector.

j. There is a tendency for the facial surface of the crown to show evidence of lobe formation by having a prominent facial ridge running axially from the facial cusp that is bordered by noticeable developmental depressions mesial and distal to it.

M D

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2. LINGUAL ASPECT - MAXILLARY FIRST PREMOLAR

a. The entire tooth converges toward the lingual and the lingual cusp is shorter than the facial cusp. The outline is a reverse image of thefacial outline.

b. The lingual cusp tip is less pointed and about 1.0 mm shorter than the facial cusp.

c. The lingual cusp tip is slightly mesial to the mesiodistal long axis bisector; therefore, the mesial cuspal ridge will be shorter than the distal cuspal ridge. It is characteristic of the lingual cusps of both maxillary premolars to “swing” or “point” to the mesial.

d. The mesial and distal outlines of the lingual cusp will both be slightly convex.

e. A small amount of both the mesial and distal surfaces of the crown will be visible.

f. The fact that the tip of the facial cusp is distal and the tip of the lingual cusp is mesial to the mesiodistal long axis bisector is very significant in distinguishing between the lingual views of maxillary premolars.

3. MESIAL ASPECT - MAXILLARY FIRST PREMOLAR

a. The outline of this tooth crown is said to be trapezoidal with thelonger parallel side at the cervix and the shorter parallel side at the occlusal. (This is true for the proximal view of all maxillary posterior teeth.)

b. The greatest contour facially will be the crest of the cervical ridge at a level within the cervical 1/3 of the crown.

c. The greatest contour lingually will be the crest of the wide convex arc of the lingual outline of the crown. This will occur at the middle 1/3 of the lingual outline of the crown. Note that there is NO ridge (elevation along a line) of enamel at this level. Posterior teeth do not have cervical ridges on their lingual surfaces.

d. The faciolingual width of the occlusal table is about ½ that of the total faciolingual width of the tooth crown. This places the cusp tips well within the confines of the root trunk.

e. The facial outline of the crown is slightly convex from the facial cusp tip to the crest of the cervical ridge.

f. The lingual outline is evenly convex from the lingual cusp tip to the cervical line.

g. The occlusal outline between cusps reflects the outline of the triangular ridges which meet at a point hidden by the outline of the mesial marginal ridge. This will be slightly lingual to the faciolingual long axis bisector. Triangular ridges on maxillary premolars tend to be approximately the same length. Their slope toward the central groove is said to be steeper than for any other tooth.

D M

L F

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h. The mesial cuspal ridges of the facial and lingual cusps

converge cervically from their respective cusp tips to meet the facial and lingual segments of the mesial marginal ridge. The crest of this mesial marginal ridge is almost perpendicular to the faciolingual long axis bisector. It is divided into a facial and a lingual segment by the MESIAL MARGINAL DEVELOPMENTAL GROOVE which crosses the ridge from the occlusal surface and extends onto the mesial surface. The maxillary first premolar is the only tooth that has such a groove. This is, therefore, a distinguishing characteristic of the tooth.

i. The cervical line curves occlusally in its middle segment approximately 1 .0 mm. This occlusal curvature of the cervical line on the mesial surface of 1.0 mm or less remains generally constant on all posterior teeth, maxillary and mandibular according to Wheeler.

j. The mesial proximal contact area is located just cervical to the facial segment of the mesial marginal ridge, facial to the mesial marginal developmental groove.

k. The area of this crown cervical to the mesial contact area will be slightly concave.

l. The faciolingual measurement of the root trunk at the cervical line is about 1.0 mm less than the overall faciolingual crown measurement (0.5 mm overhang facially and 0.5 mm overhang lingually).

m. The length of the root trunk will vary but usually the apical ¼ will definitely present a facial and lingual root. This tooth may present a single root but if it does, it will almost always have two root canals and two apical foramina.

n. All forms will have a relatively deep root depression that increases in width occlusally from the point of bifurcation to the cervical line.

o. This MESIAL DEVELOPMENTAL (ROOT) DEPRESSION crosses the cervical line and extends to the level of the junction of the cervical and middle thirds of the crown. At the level of the cervical line, the tooth surface will be convex in its facial and lingual thirds and concave in its middle 1/3. After crossing the cervical line onto the crown, the depression continues to become wider faciolingually as it progresses occlusally. The entire MESIAL DEVELOPMENTAL DEPRESION is triangular in outline with the base of the triangle at the junction of the middle and cervical thirds of the crown and its apex at the root bifurcation. For this reason, this mesial developmental depression must always be of concern to the dentist during restorative and periodontal treatment procedures.

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4. DISTAL ASPECT - MAXILLARY FIRST PREMOLAR

a. The distal outline of both the crown and root will be the reverse of the mesial outline.

b. The crest of the distal marginal ridge will be more cervically positioned (relative to the MMR) and it will be uninterrupted. There is no groove crossing the distal marginal ridge.

c. The distal contact area will still be facial to the faciolingual long axis bisector but it will be slightly higher on the tooth occlusally than the mesial contact and a little wider faciolingually since it contacts a wider tooth.

d. The crown surface cervical to the level of the contact area will be smoothly convex.

e. The root depression will not likely be as broad nor as deep as seen on the mesial surface and it does not extend across the cervical line. In fact, the root trunk in the cervical 1/3 is usually convex.

f. The cervical line crosses the surface with very little or no curvature toward the occlusal (your text lists a zero for the curvature of the cervical line on the distal surface of all permanent posterior teeth).

g. Cervical ridge extends facially 0.5 mm relative to the CEJ h. The distal proximal contact is located in the middle 1/3 of the

crown occlusogingivally.

5. OCCLUSAL ASPECT - MAXILLARY FIRST PREMOLAR

a. Occlusal outline is described in your text as a hexagon with unequal sides.

b. The facial outline will show evidence of the three lobes that make up the facial half of the tooth. There will be slight indentations in the outline corresponding to the developmental depressions between the lobes.

c. The mesial contact area will be closer to the faciolingual bisectorthan the distal contact area will be. This is logical since the tooth is near the curve of the arch and the distal contact of the canine is centered faciolingually.

d. The mesiofacial and distofacial line angles are both prominent (more angular than rounded).

e. The mesial segment of the outline measures less faciolingually than the distal outline. The mesial outline is said to reflect the contour of a figure “3” (or a reverse figure “3” for the maxillary left first premolar illustrated). This is due to the presence of the MESIAL MARGINAL RIDGE DEVELOPMENTAL GROOVE.

f. The distal segment of the outline is slightly convex, and blends smoothly into the arc of the lingual segment.

g. The crest of the lingual segment lingually will be well to the mesial of the mesiodistal bisector of the crown.

F L

M D

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h. The mesiolingual and distolingual line angles are relatively round. i. The mesial and distal cuspal ridges of the facial cusp

are almost in line with one another but they do angle across the tooth surface. The mesial end of the connected cuspal ridge line will be more to the lingual than the distal end.

j. The cusp tip of the facial cusp is positioned distal to the mesiodistal bisector. The tip is about half the distance from the facial outline to the faciolingual bisector of the crown.

k. The mesial marginal ridge is crossed near its center by the mesial marginal ridge developmental groove and is divided into two segments by the groove.

l. The distal marginal ridge is longer, uninterrupted and is slightly curved.

m. The mesial marginal ridge is said to meet the mesial cuspal ridge of the facial cusp at a 90° angle while the distal marginal ridge meets the distal cuspal ridge of the facial cusp at an acute angle.

n. The mesial and distal cuspal ridges of the lingual cusp meet at the cusp tip forming a continuous curve.

o. The tip of the lingual cusp will be mesial to the mesiodistal bisector of the crown. Lingual cusps of maxillary premolars “swing” mesially. The tip of the lingual cusp will be nearer the lingual outline of the crown than the facial cusp tip is to the facial outline.

p. The mesial cuspal ridge of the lingual cusp will be shorter than its distal cuspal ridge.

q. Triangular ridges from the facial and lingual cusps meet near the center of the occlusal table but slightly lingual to the faciolingual bisector of the crown. There is the potential for them to form a true transverse ridge. Although the crests of the two triangular ridges are in line with one another, they are almost always separated by a deep central groove. The alignment of the crests of the two triangular ridges will not be parallel to the mesiodistal bisector.

r. The central groove crosses the occlusal table mesiodistally, parallel to but slightly lingual to the faciolingual bisector of the occlusal table. The central groove more or less bisects the occlusal table into facial and lingual halves. It connects the mesial and distal triangular fossae and extends over the mesial marginal ridge as the mesial marginal ridge developmental groove. It is considered to be long when compared to the central groove of the maxillary second premolar. This also

73

places the mesial and distal triangular fossae farther apart and closer to the mesial and distal occlusal outlines than the triangular fossae of the maxillary second premolar. It also means that the marginal ridges of the first premolar will be narrower mesiodistally than marginal ridges of the maxillary second premolar.

s. There is less likelihood for the maxillary first premolar to have supplemental grooves.

t. The overall effect of the shortness of the mesial surface versus the distal surface measurement and the position of the facial and lingual cusp tips cause one authority to describe the crown from this view as appearing “twisted” or “rotated” around its long axis. Another authority describes the crown appearing as though the mesial half had been “pinched” together with pliers applied facially and lingually.

NOTES: 1. The maxillary first premolar typically has two roots, one facial and one lingual. It

always has (at least) two canals. If a third canal is present, it will be in the facial root.

2. Rarely, the maxillary 1st premolar will present with 3 roots. These teeth will have

two roots situated facially (MF & DF) and one root situated lingually. 3. The lingual cusp is typically 1.0 mm shorter than the facial cusp

. 4. The mesial marginal ridge is taller than the distal marginal ridge (the DMR is

more cervical than the MMR). 5. The middle facial lobe is the most developed of the facial lobes and gives rise to

a prominent facial ridge.

6. The maxillary first premolar emerges into the oral cavity after the permanent maxillary lateral incisor but before the permanent maxillary canine.

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PRINCIPLE CHARACTERISTICS OF A MAXILLARY FIRST PREMOLAR

1. OCCLUSAL ASPECT a. Crown outline hexagonal; occlusal table trapezoidal b. The angle formed by the convergence of the MF cusp ridge and the M marginal ridge approaches a 90° angle. c. The angle formed by the convergence of the DF cusp ridge and the D marginal ridge is acute. d. M & D triangular fossae connected by central groove that extends over MMR and onto the mesial surface as the mesial marginal ridge developmental groove or “mesial marginal groove” e. F cusp is distal & L cusp is mesial to the mesiodistal bisector

2. LINGUAL ASPECT a. Lingual cusp is 1.0 mm shorter than the facial cusp b. Lingual cusp is mesial to the mesiodistal long axis bisector

3. FACIAL ASPECT a. Prominent facial ridge running axially from the cusp tip b. M & D developmental depressions border facial ridge c. Facial cusp distal of mesiodistal long axis bisector d. Broad-shouldered with markedly convex mesial & distal contours

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5. DISTAL ASPECT a. Developmental root depression does not extend over the cervical

line b. DMR more cervical than MMR c. Facial & lingual heights of curvature extend approx. 0.5 mm

beyond the cervical line

4. MESIAL ASPECT a.. Mesial developmental root depression crosses cervical line onto the crown surface. It is triangular in shape with the apex at the root bifurcation b. Mesial marginal ridge developmental groove extends over the MMR as an extension of the central groove c. Facial root slightly longer than lingual root d. Lingual cusp approx. 1.0 mm shorter than facial cusp

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MAXILLARY SECOND PREMOLAR (aka maxillary 2nd bicuspid)

1. FACIAL ASPECT - MAXILLARY SECOND PREMOLAR

a. It should be noted that the AVERAGE measurements (given in your text for all maxillary premolars Wheeler measured) suggest that maxillary first and second premolars are essentially the same in every dimension. However, when maxillary first and second premolars are compared from the same dentition, the maxillary second premolars will measure slightly smaller than the maxillary first premolars. It is important to remember that the outlines of the teeth will differ considerably from every visual aspect.

b. The facial cusp tip will usually be slightly mesial to the mesiodistal long axis bisector. The mesial cuspal ridge is shorter than the distal cuspal ridge.

c. The facial cusp tip will be more rounded (less pointed) than the facial cusp tip of the maxillary first premolar.

d. Both proximal contact areas are at a level occlusally high in the middle 1/3 of the crown and at the same level across the tooth.

e. The outlines of the crown surfaces between contact areas and cervical line are both smooth convex curves.

f. The cervical outline of the crown is also smoothly (evenly) convex.

g. The total effect of these flowing rounded curves make the outline of the crown essentially “oval” from the facial aspect.

h. There is less evidence of the lobe structure on the facial surface of the maxillary second premolar crown as the developmental depressions are less defined than they are on the maxillary first premolar.

i. The root outline converges evenly toward a relatively blunt apex which may be centered or slightly distal to the mesiodistal long axis bisector. The maxillary second premolar has a single root.

M D

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2. LINGUAL ASPECT - MAXILLARY SECOND PREMOLAR

a. The outline of the lingual surface will be a reverse image of the facial outline.

b. Occlusally the outline of both cusps will be visible. The tip of the lingual cusp will be in line with the tip of the facial cusp. It will be nearly equal in height and a little more rounded (less pointed) than the facial cusp. The cuspal ridges of the lingual cusp will not be as high occlusally as those of the facial cusp and will present the same angle of slant from the tip of the cusp.

c. The mesial, distal and cervical outlines are such that an outline of the entire lingual surface is described as being oval in appearance.

d. The lingual surface of the root is not quite as wide as the facial surface of the root.

e. The apex of the single root is relatively blunt and will usually be distal to the mesiodistal long axis bisector.

3. MESIAL ASPECT - MAXILLARY SECOND PREMOLAR

a. The outline from the mesial aspect is described as a trapezoid with the shorter parallel side at the occlusal and the longer parallel side at the cervix.

b. The facial cusp tip is more pointed than the lingual cusp tip and is located about half way between vertical lines that mark the greatest facial curvature and the faciolingual long axis bisector of the crown.

c. The lingual cusp tip is more rounded than the facial cusp tip and the tip will be closer to the vertical line marking the greatest lingual curvature than it is to the faciolingual long axis bisector.

d. The slants of the triangular ridges are not as steep as those seen on maxillary first premolar. The mesial marginal ridge is almost horizontal across the tooth and is continuous (not divided into two segments by a groove).

e. The greatest curvature facially is the crest of the cervical ridge on the cervical 1/3 of the crown outline.

f. The greatest curvature lingually will occur about the level of the middle of the middle 1/3 of the crown outline.

g. The contact area is about 1.0 mm cervical to the crest of the mesial marginal ridge and will be slightly facial to the facio-lingual long axis bisector.

h. The mesial surface between the contact area and the cervical line is evenly convex (not at all like that of the maxillary first premolar). The cervical line curves occlusally about 1.0 mm.

i. The root converges evenly to a blunt tip which is usually slightly facial to the faciolingual long axis bisector.

j. There is a longitudinal root depression that is limited to the root (it does not cross the cervical line onto the crown).

D M

L F

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4. DISTAL ASPECT - MAXILLARY SECOND PREMOLAR

a. The distal outline will be the reverse of the mesial outline. b. The surface is very similar in all respects to the mesial

surface except that the cervical line curves a little less occlusally and may even be relatively straight.

c. The root has a longitudinal depression on the distal aspect that is confined to the root.

d. Although root depressions are found on both the mesial and distal surfaces, the root does not bifurcate.

e. Distal contact area is centered faciolingually.

F L

M D

5. OCCLUSAL ASPECT - MAXILLARY SECOND PREMOLAR

a. Although the measurements of an average maxillary second premolar are essentially the same as that of the maxillary first premolar, the second premolar from the same dentition will usually measure slightly smaller.

b. The line angles of the maxillary second premolar are more rounded and there is less evidence of the lobe structure in the facial outline. The overall effect is that the crown outline is said to be “oval” however the occlusal table outline is rectangular. There is a “balanced” look about the tooth from the occlusal aspect.

c. Both facial and lingual cusp tips are slightly mesial to the mesio-distal bisector. The cusp tips are in line with each other. The facial cusp tip is farther from the facial outline than the lingual cusp tip is from the lingual outline.

d. The triangular ridges are approximately the same length and the point at which they meet will be located slightly lingual to the faciolingual bisector of the crown. Rarely will there be a true transverse ridge since the two triangular ridges will be separated bya central groove.

e. The mesial and distal cuspal ridges of the facial cusp are relatively straight and will meet at the facial cusp at an obtuse angle. They are not aligned with one another as they are on the maxillary first premolar.

f. The mesial and distal cuspal ridges of the lingual cusp present a continuous elliptical arc.

g. Mesial and distal marginal ridges converge slightly toward the lingual. They join the cuspal ridges at relatively rounded line angles but the occlusal table is said to be rectangular in outline.

h. This tooth has mesial and distal irregular triangular fossae that are nearer the center of the tooth when compared to the maxillary first premolar. Therefore, this tooth is described as having a relatively short central groove and relatively wide marginal ridges.

i. There may be several supplemental grooves extending facially and lingually along the central groove giving the occlusal table a “wrinkled” appearance.

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PRINCIPLE CHARACTERISTICS OF A

MAXILLARY SECOND PREMOLAR

1. OCCLUSAL ASPECT a. Ovoid crown outline with MMR & DMR parallel to one another b. Rounded facial line angles (compared to maxillary 1st premolar) c. Many supplemental grooves (wrinkled appearance) d. Short “pit-like” central groove

2. FACIAL ASPECT a. Trapezoidal crown outline b. Middle facial lobe most developed of three facial lobes but less prominent

than that found on the maxillary 1st premolar. c. Developmental depressions found on either side to the facial ridge more

subtle as well

3. LINGUAL ASPECT a. Crown does have lingual convergence but not as conspicuous as that found

on maxillary 1st premolar b. Lingual cusp in line with the facial cusp and very nearly the same height

4. MESIAL ASPECT a. Contact area located in the high middle 1/3 (OG) of the tooth and

facial to the faciolingual long axis bisector of the crown b. Trapezoidal crown outline with the longer parallel side at the cervical c. Developmental root depression present but does not extend over the

cervical line onto the crown

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NOTES:

1. The maxillary 2nd premolar has two cusps (facial & lingual) of nearly equal size and height

2. The distal cuspal ridges of both cusps are longer than the mesial cuspal ridges

3. This tooth typically has one root with 2 pulp canals. There is however an extreme variation in pulp morphology.

4. Overall, this is a smaller tooth than the maxillary 1st premolar 5. Root length for this tooth will be as great (14.0 mm) or occasionally

even longer than the root of the maxillary 1st premolar. 6. The facial ridge is not as prominent as that of the maxillary 1st

premolar. 7. When compared to the maxillary 1st premolar, this tooth will usually

present with more supplemental occlusal anatomy (secondary ridges and grooves).

5. DISTAL ASPECT a. Very little (if any) curvature of the cervical line occlusally b. Developmental root depression that is confined to the root c. Distal contact area is centered faciolingually.

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PERMANENT MAXILLARY PREMOLARS

I. PERMANENT PREMOLARS (GENERAL)

CLASS TRAITS:

1. Premolars generally have two cusps (facial & lingual) but may have additional cusps or cusplets.

2. Premolars in general have a single facial cusp with one or more lingual cusps. For this reason, the preferred nomenclature for these teeth is “premolar” rather than “bicuspid” which implies the tooth has two and only two cusps. Although used with decreasing frequency, the term “bicuspid” is parlance still commonly used in dental literature and offices.

II. PERMANENT MAXILLARY PREMOLARS

KEY CONSIDERATIONS:

1. There are two major cusps, facial and lingual, that are approximately equal in size and prominence however the maxillary first premolar presents a lingual cusp that is approximately 1.0 mm shorter than the facial cusp.

2. The crowns, from the occlusal aspect, are relatively much wider (2.0 mm) faciolingually than they are mesiodistally. This characteristic is true of all maxillary posterior teeth.

3. Facial profiles viewed from the proximal aspect, are only slightly inclined lingually from height of contour to cusp apex.

4. Lingual height of contour is situated approximately midway between cervical line and the cusp tip in the middle 1/3 of the crown.

5. There is, overall, a much greater morphological similarity between the two maxillary premolars than between the two mandibular premolars.

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B. TYPE TRAITS (Maxillary premolars)

FIRST PREMOLAR SECOND PREMOLAR

Facial aspect • Prominent, broad shoulders • Facial cusp tip distal of

center • Prominent facial lobes

• Narrow shoulders • Facial cusp tip mesial of

center • Facial lobes not prominent

Lingual aspect • Entire facial profile of crown visible

• Little or none of the facial profile visible.

Mesial aspect • Mesial marginal ridge

developmental groove interrupts mesial marginal ridge.

• Usually two roots, facial and lingual.

• Mesial developmental depression extends from bifurcation of root across the cervical line and well onto crown almost to contact area.

• No mesial marginal ridge developmental groove.

• Single root. • Mesial depression restricted

to root surface.

Occlusal aspect • Crown profile hexagonal. • Mesiofacial and distofacial

line angles are sharp. • Mesial and distal profiles

converge lingually. • Occlusal table outline

trapezoidal. • Facial cusp ridge has a slight

mesial cant, giving the crown a twisted appearance.

• Facial cusp wider than lingual cusp.

• Central groove long. • Supplemental grooves rare. • Facial ridge, developmental

depressions and lobes visible.

• Crown profile ovoid. • Mesiofacial and distofacial

line angles more rounded. • Little lingual convergence;

mesial and distal marginal ridges parallel.

• Occlusal table outline rectangular.

• Crown not twisted in appearance.

• Short central groove & wide marginal ridges

• Many supplemental grooves giving a “wrinkled” appearance

Cross section of root

• Outline is kidney shaped with concavity on mesial.

• One root canal at cervix, two root canals as root bifurcates

• Outline is ovoid. • One root with one or two

root canals with varied pulp morphology

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MANDIBULAR FIRST PREMOLAR (aka mandibular first bicuspid)

1. FACIAL ASPECT:

a. Nearly symmetrical bilaterally. b. Large, pointed facial cusp with mesial cuspal ridge shorter than

distal cuspal ridge (cusp tip positioned slightly mesial of mesiodistal long axis bisector).

c. Contact areas broad occlusogingivally. d. Note slight vertical developmental depressions between lobes.

2. LINGUAL ASPECT:

a. Crown and root both taper lingually. b. Occlusal table slants (slopes) cervically in a lingual direction. c. It is possible to see much of the occlusal, mesial and distal surfaces

of this tooth when viewed from the lingual aspect. d. Lingual cusp is small (almost like a cingulum at times). e. Measurement from lingual cusp tip to cervical line is approximately

2/3 the total occlusogingival crown measurement. f. Lingual cusp tip is pointed and is in line with facial cusp tip. g. The mesiolingual groove crosses between the mesial cuspal ridge of

the lingual cusp and the mesial marginal ridge. It extends gingivally at the mesiolingual line angle of the tooth.

h. Horizontal depressions are seen bilaterally on either side of the lingual ridge just occlusal to the cervical line.

3. MESIAL ASPECT:

a. Note rhomboid form of crown outline (typical of all mandibular posterior teeth).

b. Tip of facial cusp centered over root or may be slightly facial to the faciolingual long axis bisector.

c. Tip of lingual cusp in line with lingual outline of root.

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d. Greatest curvature of facial outline in cervical 1/3 identifiable as a facial cervical ridge.

e. Greatest curvature of the lingual portion of the crown outline is at the middle 1/3 (of the entire occlusocervical measurement of the crown).

f. Facial outline convex to facial cusp tip. g. Triangular ridge of facial cusp relatively long. h. Triangular ridge of lingual cusp relatively short. i. Triangular ridges meet at a point well to the lingual of the

faciolingual long axis bisector to form a transverse ridge. j. The mesial marginal ridge slants lingually and gingivally at an angle

almost parallel to the crest of the triangular ridge of the facial cusp (approximately at a 45° angle to long axis of tooth).

k. The mesiolingual groove crosses between the mesial marginal ridge and the mesial cuspal ridge of the lingual cusp.

l. The contact area is in line with tip of the facial cusp. m. The cervical line curves occlusally approximately 1.0 mm.

4. DISTAL ASPECT:

a. Reverse of the mesial outline (with certain exceptions) b. Cervical line shows less curvature (or none) c. Distal marginal ridge is usually a little higher, curved and more

horizontal than the mesial marginal ridge. d. There is no groove crossing between the distal cuspal ridge of the

lingual cusp and the distal marginal ridge. e. The contact area is centered both faciolingually and

occlusogingivally.

5. OCCLUSAL ASPECT:

a. Outline said to be diamond shaped. b. Occlusal table said to be triangular with the base at the cuspal ridges

of the facial cusp and the apex at tip of the lingual cusp. c. Facial cusp triangular ridge long. d. Lingual cusp triangular ridge short. e. Facial and lingual triangular ridges meet to form a transverse ridge. f. Mesial fossa presents a linear mesial groove that becomes

continuous with the mesiolingual groove. This groove crosses between the mesial marginal ridge and the mesial cuspal ridge of the lingual cusp onto the lingual surface near the line angle.

g. The distal fossa usually presents a “comma” shaped curved groove.

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PRINCIPLE CHARACTERISTICS OF A MANDIBULAR FIRST PREMOLAR

1. OCCLUSAL ASPECT a. Diamond shaped crown outline b. Triangular shaped occlusal table c. Facial & lingual triangular ridges form a transverse ridge d. Mesial developmental groove continues onto the lingual surface at the ML line

angle as the mesiolingual developmental groove.

2. FACIAL (BUCCAL) ASPECT a. Characteristic mesial bulge b. Large pointed cusp slightly mesial to the mesiodistal long axis bisector

3. LINGUAL ASPECT a. Crown has characteristic lingual conversion b. Occlusal table slants cervically in a lingual direction c. Lingual cusp small (almost cingulum-like) d. Mesiolingual groove at about the area of the mesiolingual line angle

4. MESIAL ASPECT a. Characteristic rhomboid crown outline b. Tip of facial root centered over the root c. Greatest curvature of facial outline at cervical third of crown (cervical ridge) d. Greatest curvature of lingual outline at middle third of entire occlusocervical

measurement of the crown

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NOTES:

1. The mandibular 1st premolar is viewed as a transitional tooth resembling the mandibular canine but with two cusps. The facial cusp is much larger than the lingual cusp which may even resemble a cingulum.

2. The occlusal table slopes cervically in a lingual direction. It is the only

posterior tooth with this trait. 3. When viewed from the facial aspect, the tooth has near symmetrical mesial

& distal profiles. However, there is a prominent mesial “bulge”. 4. The mesiolingual groove produces a slight concavity at about the

mesiolingual line angle of the tooth. 5. The occlusal crown outline is diamond shaped. The occlusal table is

triangular.

6. There is a prominent transverse ridge from the facial cusp tip to the lingual cusp.

7. The MMR is less distinct than the DMR and slopes lingually at or about a

45° angle (approximates the DMR of the abutting mandibular canine).

5. DISTAL ASPECT a. DMR higher and more horizontal than MMR b. Contact area centered faciolingually and occlusogingivally

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MANDIBULAR SECOND PREMOLAR (aka mandibular second bicuspid)

Drawings of Mandibular Second Premolar (3 cusp variety):

1. FACIAL ASPECT:

a. Facial cusp shorter and blunter than the facial cusp of mandibular first premolar.

b. Contacts are broad occlusogingivally and are located nearer the occlusal outline than the contacts of the mandibular first premolar.

c. Crown does not converge as much toward the cervix as does the mandibular 1st premolar.

d. Mesial cuspal ridge of the facial cusp is shorter than distal cuspal ridge. (Cusp tip is located slightly to the mesial of the mesio-distal long axis bisector.)

e. The distal cuspal ridge presents a characteristic notch.

2. LINGUAL ASPECT:

a. Has two lingual cusps (3-cusp variety) separated by a lingual groove. Mesiolingual cusp is approximately 1½ mm shorter than facial cusp. Distolingual cusp is approximately 2.0 mm shorter than facial cusp.

b. The mesiolingual cusp is usually slightly wider than the distolingual cusp.

c. The lingual surface below the cuspal ridges is spheroidal. d. The lingual surface at the cervical line is almost as wide as the surface at

the cervical line on the facial surface (crown does not converge as much toward the lingual as does the crown of the mandibular first premolar).

3. MESIAL ASPECT

a. Facial outline crests in the cervical 1/3 as a cervical ridge. b. Greatest lingual curvature is located rather high (occlusally) in the

middle 1/3. c. Facial cusp tip is slightly facial to the center of the root measured

faciolingually. d. The mesiolingual cusp tip is very near the lingual outline and more or

less in line with the lingual outline of the root. e. The mesial marginal ridge is relatively high (occlusally) and much more

nearly horizontal than was observed on the mandibular first premolar. f. The cervical line curves occlusally about 1.0 mm.

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4. DISTAL ASPECT

a. The distal surface outline is the reverse of the mesial outline. b. The distal marginal ridge is slightly lower than the mesial marginal

ridge thus allowing more of the occlusal surface to be visible. c. Since the distolingual cusp is ½ mm shorter than the mesiolingual cusp,

the outline of the shorter cusp is superimposed over the outline of the taller mesiolingual cusp.

d. The cervical line curves less toward the occlusal and is often almost flat. e. Lingual height of contour described to be at the occlusal ⅓

5. OCCLUSAL ASPECT

a. Contact areas are located slightly facial to the faciolingual bisector and are fairly wide faciolingually.

b. The facial outline is fairly rounded and may not present the usual three lobe appearance.

c. The occlusal crown outline form is described as being “nearly square”. There is no dramatic lingual convergence as seen on the mandibular first premolar. The lingual mesiodistal measurement may actually be wider than the facial mesiodistal measurement. This is the only mandibular tooth (3-cusp variety only) that has the potential to exhibit “lingual divergence”.

d. The lingual outline is fairly straight presenting a slight indentation in the lingual groove area.

e. There are three distinct cusps (listed according to size: facial, mesiolingual and distolingual).

f. The facial cusp tip is located slightly to the facial of the faciolingual bisector and slightly mesial to the mesiodistal bisector.

g. The tips of the lingual cusps are located quite near the lingual outline. h. The mesiolingual cusp is slightly wider than the distolingual cusp. i. Cuspal ridges extend mesially and distally from the cusp tips to join relatively

straight almost parallel marginal ridges. j. None of the triangular ridges meet to form transverse ridges. k. There is a central fossa that is generally located midway between the facial

and lingual outlines of the occlusal table (3-cusp variety only). l. From the central pit in the central fossa radiate the lingual, mesial and distal

grooves, forming a “Y” shaped pattern. m. The mesial and distal grooves end respectively in their mesial and distal

triangular fossa.

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PRINCIPLE CHARACTERISTICS OF A MANDIBULAR SECOND PREMOLAR

2. FACIAL ASPECT a. Occlusocervical crown dimension is greater than the mesiodistal crown

dimension b. Crown outline form described as trapezoidal or pentagonal c. Tendency for distal curvature of root tip

3. LINGUAL ASPECT a. Of the two lingual cusps, the ML is the larger occupying 2/3 of the

mesiodistal crown dimension b. Less lingual convergence than found on mandibular 1st premolar c. 3-cusp variety likely to have lingual divergence

4. MESIAL ASPECT a. Crown outline rhomboidal b. MMR horizontally positioned at a rt. angle to the faciolingual long-

axis bisector of the tooth c. Facial cusp tip slightly facial to the FL long axis bisector d. ML cusp in line with the lingual outline of the root e. Mesial contact area oval shaped (FL direction) and is facial to the

faciolingual long axis bisector f. Lingual height of contour located at the occlusal ⅓

5. DISTAL ASPECT a. 3-cusp variety: all 3 cusps are visible from this aspect b. DMR cervical to MMR showing more of the occlusal surface c. Distal contact area ovoid (FL direction) and is facial to the

faciolingual long axis bisector d. Lingual height of contour located at the occlusal ⅓

1. OCCLUSAL ASPECT a. May present with two or three cusps. 2-cusp variety may have “H” or “U” shaped grove pattern; 3-cusp variety will have a “Y” shaped occlusal groove pattern b. No transverse ridges extending between facial and lingual cusps c. 3-cusp variety only mandibular tooth to exhibit lingual divergence

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MANDIBULAR SECOND PREMOLAR: 2-CUSP VARIETY

1. Crown outline described as round or oval 2. Occlusal groove pattern resembles a “U” or an “H” 3. Has a central developmental groove connecting the mesial and distal fossae 4. Has a transverse ridge connecting the facial and lingual cusps 5. Occlusal crown outline will exhibit lingual convergence unlike the 3-cusp variety mandibular 2nd premolar which may exhibit lingual divergence

PERMANENT MANDIBULAR PREMOLARS (general traits)

1. Have a single, well-developed facial cusp, however the lingual cusp or

cusps may vary in size and development and are never as well developed as the facial cusp.

2. The crowns, from the occlusal aspect, are more nearly the same diameter faciolingually and mesiodistally (the faciolingual measurement is greater than mesiodistal measurement by only 1.0 mm or less).

3. Facial profiles, viewed from the proximal aspect, are significantly inclined lingually from the height of contour (cervical ridge) to the tip of the facial cusp.

4. Lingual height of contour is situated more occlusally much nearer the tip(s) of the lingual cusp(s). This is still considered to be the middle third of the crown when compared to the crown’s overall occlusocervical measurement. However some text books reference the lingual height of contour as being in the occlusal 1/3 of the crown because it is referencing an OC measurement from the tip(s) of the lingual cusp(s) to the cervical line.

5. The mandibular first premolar and the 3-cusp variety mandibular second premolar do not share a great deal of morphological similarity. The mandibular 1st premolar and the 2-cusp variety mandibular 2nd premolar demonstrate significant lingual convergence. The 3-cusp variety mandibular 2nd premolar may demonstrate lingual divergence, that is to say the mesiodistal measurement of the lingual surface may be greater than that of the facial surface.

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TYPE TRAITS (Mandibular premolars)

FIRST PREMOLAR SECOND PREMOLAR

1. Facial aspect • Crown not as bilaterally symmetrical

• Crown bilaterally symmetrical

2. Lingual aspect

• Entire facial profile visible

• Almost entire occlusal surface visible

• Lingual cusp much smaller and lower than facial cusp

• None of facial profile visible

• Little if any of occlusal surface visible

• Facial and lingual cusps almost equal in height

3. Mesial aspect

• Occlusal plane tilted lingually

• Transverse ridge links tips of the facial and lingual cusps

• Mesial marginal ridge inclines cervically about 45°

• Mesiolingual groove

• Occlusal plane horizontal

• No transverse ridge (except 2-cusp variety)

• Mesial marginal ridge is horizontal

• Lingual groove separating lingual cusps (3-cusp variety)

4. Occlusal aspect • Occlusal crown outline

diamond shaped • Mesial and distal

profiles converge lingually

• Occlusal table triangular in outline

• Facial cusp more than twice the size of lingual cusp

• Mesial marginal ridge shorter and less prominent than distal marginal ridge

• Absence of Y pattern formed by grooves

• No pit

• Occlusal crown outline square or oval

• Mesial and distal profiles straight and parallel

• Occlusal table square in outline

• Facial and lingual cusps nearly equal in size

• Mesial and distal marginal ridges about same length and prominence

• Main grooves form Y pattern (3-cusp)

• Central pit

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PERMANENT MAXILLARY FIRST MOLAR

1. OCCLUSAL ASPECT – MAXILLARY FIRST MOLAR

a. Average mesiodistal diameter - 10.0 mm b. Average faciolingual diameter – 11.0 mm c. Somewhat rhomboidal crown outline. d. Crown wider mesially than distally (distal convergence)

and wider lingually than facially (unique feature of this tooth).

e. Four well developed cusps. One minor fifth cusp (Carabelli’s) on the lingual of and augmenting the mesiolingual cusp.

f. Cusp size: very large mesiolingual cusp followed in size bymesiofacial, distolingual, distofacial and fifth (Carabelli’s) in that order. The maxillary first molar has a well developed distolingual cusp.

g. Mesial contact area is facial to the faciolingual bisector. Distal contact area is centered faciolingually.

h. The oblique ridge (characteristic of all maxillary molars) extends from the tip of the mesiolingual cusp diagonally across the tooth to the tip of the distofacial cusp. The oblique ridge is produced by the meeting of (1) the triangular ridge of the distofacial cusp and (2) the distal cuspal ridge of the mesiolingual cusp. The low point of the ridge (where the two ridges meet) is at the same level as themesial and distal marginal ridges.

i. Each major cusp has a triangular ridge that extends from the cusp tip down into the central portion of the occlusal surface

j. Each cusp has cuspal ridges that extend laterally (mesially and distally) from the tip of the cusp.

k. The mesial marginal ridge and distal marginal ridge mark the mesial and distal margins of the occlusal table. They are confluent with the mesial and distal cusp ridges of the major mesial and distal cusps. Each marginal ridge typically has a marginal groove, a supplemental groove emanating from the pit in their respective triangular fossae (see “1.m” below). l. There are two major fossae located on either side of the

mid-point of the oblique ridge. They are named the central fossa (in the center of the occlusal surface) and the distal fossa (on the distal side of the oblique ridge)

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m. There are two minor fossae located toward the center of the tooth from the mid-points of the marginal ridges. These are named the mesial triangular fossa and the distal triangular fossa. There are four fossae on the occlusal surface of the maxillary first molar, 2 major & 2 minor.

n. The central groove runs from the central pit in the central fossa to the mesial pit in the mesial triangular fossa. The facial groove runs from the central pit straight to and then onto the facial surface of the tooth. The distal oblique groove runs from the pit in the distal triangular fossa through the distal fossa and continues diagonally toward the lingual surface where it meets and becomes continuous with the lingual groove. The lingual groove crosses over onto the lingual surface of the crown separating the mesiolingual and distolingual cusps. It terminates near the center of the lingual surface in a lingual fossa or pit. Sometimes, there is a groove which crosses the oblique ridge. This groove, when present, is called the transverse groove of the oblique ridge. There are usually shallow, short supplemental grooves running toward the corners of the tooth from the mesial and distal triangular fossae.

2. FACIAL ASPECT – MAXILLARY FIRST MOLAR

a. The crown outline of facial surface is trapezoidal. b. Typically, maxillary molar facial cusps are taller than

lingual cusps and mesial cusps are taller than distal cusps. The MF & DF cusps of the maxillary 1st molar are very nearly the same height. On occasion, the DF cusp will even be taller than the MF cusp.

c. Facial cusps are more pointed than lingual cusps. d. Cuspal ridges of the mesiofacial cusp meet at an obtuse

angle. e. The cuspal ridges of the distofacial cusp meet at a 90° or

right angle making it a sharper cusp than the MF cusp. f. Usually the crown is longer in the mesial half, but

occasionally the distofacial cusp will be as tall as or taller than the mesiofacial cusp.

g. The facial groove extends occlusocervically between the mesiofacial and distofacial cusps to a point near the center of the facial surface.

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h. The facial surface shows a slight depression extending laterally (both mesially and distally) from the cervical limit of the facial groove. This depression is just occlusal to and parallel to the cervical ridge.

i. The facial surface demonstrates vertical facial ridges extending cervically from the cusp tip of each facial cusp. The cervical ridge runs mesiodistally just above the cervical line but only in the mesial two-thirds of the cervical third of the crown.

j. The cervical line curves apically and may come to a definite point near the center, in alignment with the furcation between the mesiofacial and disto-facial roots.

k. The mesiofacial root extends in a mesial direction for two-thirds of its length. It then curves slightly to the distal. Its apex is said to be in alignment with the tip of the mesiofacial cusp.

l. The distofacial root is generally straighter and slightly shorter than the mesiofacial root. Its apex is usually in line with the distal outline of the crown.

m. The root trunk (the root portion that extends from the cervical line to where it bifurcates) on the facial aspect of the tooth averages 4 mm in length. There is a broad concave area between the roots extending from the cervical line into the furcation area.

n. The lingual (or palatal) root may also be seen from the facial view of this tooth. It is the longest of the three roots by about 1.0 mm. Its apex is in line with the facial groove when viewed from this aspect.

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3. LINGUAL ASPECT – MAXILLARY FIRST MOLAR

a. Usually, only the lingual cusps will be seen from this aspect since they are larger and block the facial cusps from view unless the tooth is tipped slightly.

b. The mesiolingual cusp is very wide mesiodistally and is said to occupy about three-fifths of the total mesio-distal measurement of the crown. Its cuspal ridges meet at a rather wide obtuse angle at the cusp tip. Its mesial cuspal ridge meets the relatively straight mesial outline of the crown at a 90° right angle.

c. The distolingual cusp is well developed. It takes up the remaining two-fifths of the total mesiodistal width of the crown. Its tip is so rounded that it is sometimes described as spheroidal. The occlusal outline of this cusp joins the distal outline of the crown in an arc that is almost that of a semicircle.

d. The fifth (or Carabelli’s) cusp is located on the lingual aspect of the mesiolingual cusp. Its cuspal ridges are parallel to, and about 2.0 mm cervical to the occlusal outline of the mesiolingual cusp. Sometimes this cusp can be so well developed that the cusp angle will be 90°, i.e sharper and less obtuse than the mesiolingual cusp. Other times this cusp will be hardly distinguishable at all. As with all cusps, the fifth cusp is considered to have four cuspal ridges, albeit at times they may be difficult to define.

e. The lingual groove begins at the lingual border of the occlusal table as an extension of the distal oblique groove. From this origin between the mesiolingual and distolingual cusps, it slants cervically and diagonally across the lingual surface until it reaches a position near the center of the mesiodistal width of thesurface then it turns more parallel with the long axis of the tooth. It ends in a fossa (sometimes a pit) near the center of the lingual surface.

f. All three roots will be visible from a lingual view. Theapex of the lingual (palatal) root will be in line with the occlusal end of the lingual groove as it crosses between the mesiolingual and distolingual cusps to join the distal oblique groove.

g. There is a shallow developmental depression in the middle one third of the lingual (palatal) root that extends occlusally on the root and across the cervical line onto the cervical third of the crown.

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4. MESIAL ASPECT - MAXILLARY FIRST MOLAR

a. The crown outline from the mesial view is trapezoidal with the shorter parallel side at the occlusal and the longer parallel side at the cervix.

b. The greatest curvature of the facial outline is within the cervical third of the crown.

c. The greatest curvature of the lingual outline is near the middle third of the crown.

d. Since the ML cusp is taller than the DL cusp and the MF cusp is taller than the DF cusp and the mesial marginal ridge is higher than the distal marginal ridge, little if any of the occlusal anatomy is visible from this view.

e. The lingual outline of the crown will reflect the position of the fifth (Carabelli’s) cusp by showing a slight indentation about 2.0 mm cervical to the mesiolingual cusp tip.

f. The cervical line curves occlusally about 1.0 mm. The crest of this curvature will reach its highest position occlusally at a point slightly facial to the faciolingual long axis bisector.

g. Only two of the three roots of this tooth are visible from the mesial view since the mesiofacial root is much wider faciolingually and slightly longer than the distofacial root.

h. The root trunk is shorter on the mesial aspect than on the facial, however the mesial surface shows a similar concavity between the trifurcation area and the cervicalline.

i. The mesiofacial root is broad and flattened on its mesial aspect. Its width faciolingually from facial outline to the area of furcation is approximately two- thirds of the cervical measurement of the crown.

j. The mesiofacial root presents a relatively wide but shallow depression for almost its entire length. This root depression extends occlusally across the root trunkarea and cervical line onto the cervical one-third of the crown.

k. The facial outline of the mesiofacial root often extends facially in its middle one-third a little beyond the greatest projection of the crown and then curves lingually to a relatively blunt apex that is more or less in line with the tip of the mesiofacial cusp. The lingual outline is relatively straight to the area of trifurcation.

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l. The lingual (palatal) root is the longest of the three roots. It is said to be banana shaped. From the mesial view the facial outline of this root is concave while the lingual outline is convex. The lingual outline of this root in its middle and even its apical third may extend lingually beyond the greatest lingual projection of the crown.

5. DISTAL ASPECT - MAXILLARY FIRST MOLAR a. From the distal view the crown outline is also

trapezoidal. The greatest facial curvature of the outline will crest in its cervical third; lingually the greatest curvature will crest in middle third of the crown length.

b. Since the crown of this tooth is shorter in its distal half, it is possible to see quite a bit of the occlusal anatomy from the distal aspect. The occlusal outlines of the mesiofacial and mesiolingual cusps will be seen extending occlusally beyond the outlines of the shorter distofacial and distolingual cusps.

c. Like all molars, the crown of this tooth is narrower in its distal half. Most of this convergence to the distal takes place because the facial cervical ridge flattens out in the distal half of the tooth. It is therefore possible to see much of the facial surface when viewing the tooth from the distal aspect.

d. The cervical line across the distal surface is relatively straight and presents little or no curve occlusally.

e. All three roots will be visible from a distal view. f. The distofacial root is narrower at its base than the

other roots and is normally the shortest of the three roots. It continues to be relatively narrow facio-lingually and its outline will be superimposed over the outline of the wider mesiofacial root. The distal surface of the root trunk is likely to show a shallow root depression that extends occlusally to the cervical line. The distofacial portion of the depression (above the DF root) will extend occlusally over the cervical line onto the cervical ⅓ of the crown surface. The outline of the lingual (palatal) root will be similar to that seen from a mesial view (banana shaped).

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g. The distal surface of the root trunk is generally smoothly rounded and convex. There is a small, shallow depression in the root trunk over the distofacial root that extends across the cervical line onto the cervical third of the crown surface. However, there is little or no depression between the furcation area and the cervical line as was described on the facial and mesial aspects.

h. The root trunk on the distal aspect is longer than its measurement on the facial aspect by about 1.0 mm. Its total length will average about 5.0 mm.

NOTES:

1. Primary Cusp Triangle: Formed by the three major cusps (mesiofacial, distofacial and mesiolingual). Characteristic of all maxillary molars.

2. The permanent maxillary 1st molar measures a wider lingual surface

mesiodistally than it does on its facial surface. This makes this permanent tooth unique (along with the 3-cusp variety mandibular 2nd premolar) in that it does not exhibit lingual convergence.

3. Anomalies: Mulberry molar is a developmental anomaly associated with

congenital syphilis and Hutchinson’s Incisor. Otherwise there are few as this tooth is very consistent in its size and form as it develops.

4. MF root has a 50% probability of having two root canals. If it does, one

will be facial and one will be lingual.

5. Root lengths: L > MF > DF

6. Facial & lingual heights of contour extend approx. 0.5 mm beyond the cervical line.

7. Facial roots are wider in a faciolingual direction; lingual root is wider in a

mesiodistal direction

8. Root Depressions: On all three roots (always on widest surface). The mesial, distal and lingual root depressions cross the CEJ onto crown surface. The facial root (trunk) depression does not cross onto the facial surface.

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DENTAL ANATOMY PRINCIPLE CHARACTERISTICS OF A

PERMANENT MAXILLARY RIGHT FIRST MOLAR

1. OCCLUSAL ASPECT a. Rhomboidal crown outline; ML & DF line angles obtuse b. Crown dimension wider lingually than facially c. Mesial contact facial to the FL bisector; distal contact is centered d. Two major fossae: central & distal; two minor: M & D triangular fossae e. Central groove runs from central pit (central fossa) to mesial pit (MTF) f. Primary cusp triangle (all maxillary molars): MF, DF, ML cusps

2. BUCCAL ASPECT a. Facial cusps more pointed than lingual cusps b. Facial groove separates MF & DF cusps c. M & D cuspal ridges of MF cusp meet at an obtuse angle; M & D cuspal

ridges of DF cusp meet at a 90° angle d. MF root is the 2nd longest root supporting the 2nd largest cusp e. MF root tip lines up with MF cusp; DF root tip lines up with DF cusp f. L root tip lines up with F groove

3. LINGUAL ASPECT a. ML cusp the largest of all cusps and occupies 60% of the MD measurement b. DL cusp well-developed and occupies remaining 40% of MD measurement c. 5th (Carabelli) is on the lingual surface of and augments the ML cusp d. Lingual (extension of distal oblique) groove separates the ML & DL cusps e. Developmental root depression that crosses over the cervical line onto the

lingual surface of the crown

4. MESIAL ASPECT a. Trapezoidal crown outline b. MF root is broad faciolingually and occupies ⅔ of the FL measurement c. Developmental root depression extends over the cervical line onto the crown d. Facial ht. of curvature at cervical ⅓ (cervical ridge); lingual ht. of curvature

in middle ⅓ of crown e. 5th (Carabelli) cusp approx 2.0 mm cervical to ML cusp tip

5. DISTAL ASPECT a. Measurement of crown is narrower & shorter than on mesial b. Cervical ridge flattens and is not evident on distal half of crown c. Shallow developmental root depression that crosses over the cervical line

onto the crown surface

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PERMANENT MAXILLARY SECOND MOLAR

1. OCCLUSAL ASPECT - MAXILLARY SECOND MOLAR

a. Average mesiodistal diameter - 9.0 mm. b. Average faciolingual diameter - 11.0 mm. c. Crown outline from this view will usually be that of a

rhomboid. The mesiolingual line angle and distofacial line angle are obtuse. The distofacial line angle and mesiolingual line angle are obtuse. This rhomboidal form presents four well developed functional cusps on its occlusal surface.

d. The central groove extends mesially from the central pit in the central fossa to the mesial pit in the mesial triangular fossa.

e. The distal oblique groove extends from the distal pit in the distal triangular fossa in a lingual direction parallel to the oblique ridge. It continues onto the lingual surface as the lingual groove.

f. The maxillary 2nd molar has similar occlusal anatomy to the maxillary 1st molar with the following exceptions:

1. Rarely has fifth or Carabelli’s Cusp. 2. The distolingual cusp is smaller. In some specimens, it

is quite small giving this tooth a “heart shaped” appearance which is more characteristic of a third molar crown. The primary cusp triangle characteristic of all maxillary molars is identifiable since it does not include the distolingual cusp.

3. This “heart” type is still considered to have four cusps although at least one textbook considers this tooth to have only three functional cusps.

4. When the distolingual cusp is small in size, the oblique ridge and the distal marginal ridge often become difficult to distinguish as separate landmarks.

5. In some specimens, the triangular ridge of the distofacial cusp and the distal cuspal ridge of the mesiolingual cusp do not exactly meet and the transverse groove of the oblique ridge is quite deep.

6. When compared to the first molar, the maxillary secondmolar usually has more secondary grooves.

g. The mesial contact area is located facial to the faciolingual bisector. The distal contact area is centered faciolingually.

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2. FACIAL ASPECT - MAXILLARY SECOND MOLAR

The permanent maxillary second molar from the facial view is similar to the first molar with the following exceptions:

1. The difference in cusp height of the two facial cuspsis greater. The distofacial cusp of this tooth is always shorter than the mesiofacial cusp. The maxillary second molar is positioned in the arch such that the facial cusp tips maintain the convex arc of the Curve of Spee.

2. The facial groove is shorter. 3. The lateral depression described for the first molar

is not present or is very shallow on the second. 4. The root trunk is longer than that of the 1st molar. 5. The overall root lengths (as measured from the

cervical line to the apices of the root tips) may be as long or even longer than the roots of the maxillary 1st molar. The actual roots (as measured from the bifurcation to the root tip apices) are shorter and less divergent. In fact, in a few instances they will be very close together or even fused. They are much more likely to curve distally.

3. LINGUAL ASPECT - MAXILLARY SECOND MOLAR

The permanent maxillary second molar is similar in outline and anatomical morphology to the maxillary first molar with the following exceptions:

1. The mesiolingual cusp is more nearly centered. 2. The distolingual cusp is shorter and much less

developed. 3. Very rarely is there a fifth (Carabelli’s) cusp. 4. No root depression extending onto the crown is

described. 5. Roots curve to the distal so that the lingual

(palatal) root apex is in line with the distolingual cusp.

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NOTES:

1. Root lengths: L > MF > DF 2. Roots are less divergent than those of the maxillary 1st molar 3. Developmental depressions on roots are limited 4. Facial roots wider faciolingually; lingual root wider mesiodistally 5. More supplemental grooves and wrinkled occlusal anatomy than

maxillary 1st molar 6. Develops from four lobes unless 5th cusp present which is very rare

4. MESIAL ASPECT - MAXILLARY SECOND MOLAR

The mesial view of a permanent maxillary second molar is similar to that of the first molar with the following exceptions:

1. There is no fifth (Carabelli’s) cusp 2. The roots, though similar in number, shape

and distribution are closer together and are never wider in total faciolingual measurementthan the crown. They are described as being “within the confines of the crown”.

3. No root depression area is described extending onto the crown. The root depressions found on the mesiofacial root surface are confined to the root.

5. DISTAL ASPECT - MAXILLARY SECOND MOLAR

This view of the permanent maxillary second molar is also similar to that of the first molar with these exceptions:

1. More of the occlusal anatomy is visible because the distal cusps are significantly shorter than the mesial cusps.

2. All three roots are visible but they are shorter and less divergent.

3. There is no developmental depression extending from the root trunk onto the distal portion of the crown.

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PRINCIPLE CHARACTERISTICS OF A MAXILLARY RIGHT SECOND MOLAR

1. OCCLUSAL ASPECT a. Four cusps: ML > MF > DF > DL b. Wrinkled occlusal anatomy due to more supplemental grooves c. Rhomboid crown outline d. Primary cusp triangle e. DL cusp may be quite small

2. BUCCAL ASPECT a. MF cusp taller than DF cusp (Curve of Spee) b. Short facial groove c. Roots have a distal cant and remain within the confines of the crown outline

3. LINGUAL ASPECT a. 5th (Carabelli) cusp rarely seen b. DL cusp may be quite small c. Root depression does not cross CEJ onto crown surface

4. MESIAL ASPECT a. Root depression on MF root confined to the root b. Roots confined within the outline of the crown c. M contact area facial of central groove

5. DISTAL ASPECT a. All four cusps are visible b. All three roots are visible c. D contact area centered faciolingually

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PERMANENT MAXILLARY THIRD MOLAR

1. OCCLUSAL ASPECT- MAXILLARY THIRD MOLAR

a. Average mesiodistal crown diameter - 8.0 mm. b. Average faciolingual crown diameter - 10.0 mm. c. Generally, this tooth has the greatest variation in morphology

of any tooth in the permanent dentition. d. From the occlusal view, the crown outline is described as

heart shaped. e. The occlusal anatomy is similar to that of other maxillary

molars. This is particularly true of the Primary Cusp Triangle (Trigon) area. The distolingual cusp and distal marginal ridge will be dissimilar in the following ways:

1. The distolingual cusp will be shorter and narrower (mesiodistally).

2. The distal outline will be more rounded. 3. It is often difficult to distinguish definite, separate

cuspal and triangular ridges on the distolingual cusp. 4. Often, the distolingual cusp is seen as only a minor

elevation or “Talon”. 5. Often, the distal marginal ridge is hardly discernible. 6. Likewise, definite lingual, distal oblique and

distolingual grooves are hard to distinguish. 7. Often, this whole area of the crown becomes a single

convex roll of enamel from the crest of the oblique ridge onto the distal surface.

2. FACIAL ASPECT - MAXILLARY THIRD MOLAR

The maxillary third molar from the facial view is very similar to that view of the permanent second maxillary molar with the following (expected) exceptions:

1. Crown length is shorter. 2. There is more evidence of the Curve of Spee. 3. Mesiofacial cusp width mesiodistally is

proportionately wider when compared to the width of distofacial cusp.

4. Root structure will vary from tooth to tooth. Rootsare the same in name, number and arrangement but they are usually more curved to the distal, closer together and are often fused.

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3. LINGUAL ASPECT - MAXILLARY THIRD MOLAR

The maxillary third molar from the lingual view is also similar to that view of a permanent maxillary second molar with some exceptions:

1. The mesiolingual cusp tip is more centered mesiodistally.

2. The mesiolingual cusp dominates the mesiodistal width of the crown.

3. Often the distolingual cusp is so short, narrow and rounded that the lingual groove is evident as a mere fold in the enamel and the cusp seems to have little height at all.

4. Difference in root curvature and divergence as described above.

4. MESIAL ASPECT - MAXILLARY THIRD MOLAR

The maxillary third molar from the mesial view is probably more like the mesial view of the permanent maxillary second molar than from any other visual aspect of the tooth. There are hardly any exceptions or differences other than the fact that roots may be closer together or even fused.

5. DISTAL ASPECT - MAXILLARY THIRD MOLAR

The same statement concerning similarities to a permanent maxillary second molar may be made when the distal view is considered. Perhaps a little more of the facial and occlusal surfaces are in sight because the crown converges proportionately more so than does the second molar crown (toward the distal in both mesiodistal and occlusogingival measurements). All three roots are usually discernible although they may be fused.

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DENTAL ANATOMY PRINCIPLE CHARACTERISTICS OF A MAXILLARY RIGHT THIRD MOLAR

1. OCCLUSAL ASPECT a. Type I: 3 cusps, heart shaped, vestigial or no distolingual cusp b. Type II: 4 cusps, rhomboid shaped (less common than Type I) c. Shallow central groove d. Many supplemental grooves

2. BUCCAL ASPECT a. Shortest OC crown height of all the maxillary molars b. DF cusp shorter than MF cusp, i.e. more evidence of the Curve of Spee c. MF cusp wider than DF cusp d. Roots vary but will have a distal cant, are close together and often fused

3. LINGUAL ASPECT a. ML cusp is centered mesiodistally b. ML cusp dominates the lingual width of the crown c. Depending on Type, DL cusp may be present, vestigial or absent d. Roots close together and often fused

4. MESIAL ASPECT a. Most resembles maxillary 2nd molar from this aspect b. Any developmental root depressions will not cross cervical line onto the

crown surface

5. DISTAL ASPECT a. Significant distal convergence both in a mesiodistal and occlusocervical

direction b. From this aspect, more of the occlusal and facial surfaces can been seen

than were visible on the maxillary 2nd molar.

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PERMANENT MAXILLARY MOLARS

I. Permanent Molars (General)

Class Traits:

1. Molars have the largest occlusal surfaces of any teeth in the arch. 2. Molars have 3 to 5 major cusps. 3. Molars are the only teeth that have at least two facial cusps. 4. Molars have multiple large roots (usually two or three).

II. Permanent Maxillary Molars

Arch Traits:

1. There are generally three roots, two facial and one lingual. 2. As a general rule, mesial cusps will be taller than distal cusps and facial cusps

will be taller than lingual cusps. The DF cusp of the maxillary 1st molar may be as long as or sometimes even longer than the MF cusp.

3. The mesiolingual cusp as the supporting or centric cusp will be the largest cusp in size. The second largest cusp is typically the mesiofacial cusp. The third largest cusp of the permanent maxillary 1st molar is the distolingual cusp followed by the distofacial cusp. The maxillary 2nd and 3rd molars third largest cusp is the DF cusp as the DL cusp is much smaller in size and can sometimes be only a minor elevation (talon).

4. The mesiofacial, distofacial and mesiolingual cusps are arranged in a tricuspate triangular pattern (trigon) more commonly termed the “primary cusp triangle”.

5. Generally there are these three major cusps (primary cusp triangle) and a fourth cusp (distolingual) of lesser size. As noted above, an exception may be the maxillary 1st molar. Wheeler describes the distolingual cusp as being the third largest of the five cusps. Nevertheless, the MF, DF and ML cusps constitute the primary cusp triangle of the maxillary first molar.

6. These crowns are always wider faciolingually than mesiodistally. 7. The distofacial and mesiolingual cusps are, with few exceptions, connected by

the oblique ridge. III. Maxillary Third Molars

1. Extremely variant in size and can be very small 2. Have more rounded features than do the other maxillary molars 3. Roots have a distal cant and are often fused 4. Are frequently missing 5. Type I: Three cusps (no DL cusp) and heart shaped occlusal crown outline 6. Type II: Four cusps and rhomboid shaped occlusal crown outline 7. An oblique ridge is said to be present in both Type I and Type II maxillary third

molars although in Type I it may be difficult to differentiate it from the distal marginal ridge.

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Type traits (Maxillary molars) First Molar Second Molar Third Molar Facial aspect

a. Widest (FL) of the three molars

b. Facial cusps equal in height.

c. Apex of MF root directly in line with tip of MF cusp.

a. Intermediate in width

b. DF cusp slightly shorter than MF

c. MF root apex in line with center of crown.

a. Smallest b. DF cusp much

shorter than MF. c. Roots show

pronounced distal inclination and are often fused

Lingual aspect

a. DL cusp largest of the three molars.

a. DL cusp smaller in width and height.

a. DL cusp usually vestigial or missing.

Mesial aspect

a. Lingual root wide mesiodistally.

b. MF and lingual roots project beyond crown profiles.

a. Lingual root narrower.

b. MF and lingual roots much less divergent.

a. Lingual root narrowest.

b. MF and lingual roots often fused.

Occlusal aspect

a. Crown outline

square to rhomboidal.

b. Oblique ridge prominent.

c. Large talon (distolingual cusp).

a. Rhomboidal form more pronounced in crown outline. b. Oblique ridge

smaller. c. Medium talon

(DL cusp)

a. Heart shaped (I)

or rhomboid (II) crown outline.

b. Oblique ridge barely discern-able or absent.

c. Talon vestigial.

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DENTAL ANATOMY LABORATORY PERMANENT MANDIBULAR FIRST MOLAR

n. There are four major developmental grooves. The central groove runs irregularly mesio-distally across the occlusal surface from the

1. OCCLUSAL ASPECT - MANDIBULAR FIRST MOLAR

a. Average mesiodistal diameter - 11.0 mm. b. Average faciolingual diameter - 10.5 mm. c. Occlusal crown outline said to be hexagonal (Wheeler)

or pentagonal (Kraus) d. Faciolingual measurement is greatest in mesial half of

crown (because of cervical ridge). e. Tooth converges toward lingual. The facial half of the

crown is much wider than lingual half. f. Mesial contact area is located slightly facial to the

faciolingual bisector and about 1.0 mm cervical to mesial marginal ridge.

g. Distal contact area is also located facial to the faciolingual bisector and about 1 .0 mm cervical to the distal cuspal ridge of the distal cusp.

h. Crown has five cusps. Three cusps are located on the facial half of the crown and two cusps are located on the lingual half.

i. The most distally located cusp on the facial half is located far enough around on the corner of the crown to be called the distal cusp.

j. The other cusps are named according to their general location as mesiofacial, distofacial, mesiolingual and distolingual.

k. In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.

l. In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.

m. There is one major fossa - the central fossa and two minor fossae - the mesial triangular fossa and the distal triangular fossa.

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mesial pit in the mesial triangular fossa through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from the central groove in a distofacial direction at the deepest part of the sulcus between the distofacial and distal cusps.

n. The mesiofacial groove and the distofacial groove extend over onto the facial surface of the crown.

o. The groove pattern of this tooth is described by various authors as shaped like a “W” or “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central groove (depending on the perspective of the viewer). The “Y” comparison considers the paths of the mesiofacial, distofacial and lingual grooves and that segment of the central groove between them. It ignores the mesial and distal extensions of the central groove.

p. Note that each cusp has a definite triangular ridge, but also note that none of them meet. This produces an occlusal surface that has no transverse ridges.

2. FACIAL ASPECT - MANDIBULAR FIRST MOLAR

a. Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.

b. All cusps are visible since the lingual cusps are taller than facial cusps.

c. As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more rounded.

d. The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total mesiodistal width of the facial surface because most

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of the cusp is lingual to the distofacial line angle placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed than either the mesiofacial or distofacial cusp.

e. There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.

f. The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary restorations.

g. The facial cervical ridge occupies the area cervical to the lateral depression described above for approximately the mesial 2/3 of the mesiodistal width of the tooth.

h. The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its length.

i. The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.

j. The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or slightly convex.

k. The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown surface of the tooth.

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l. The two roots are positioned mesially and distally.

The roots of the mandibular first molar are usually longer and more divergent than those of the mandibular second or third molar.

m. The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The distal outline of the root is concave.

n. The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally in its apical 1/3 but it may be straight or even curve slightly to the mesial.

o. Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots have root depressions on their mesial and distal aspects that are not seen from this view.

e. It should be noted that the anatomical crown length is the same when measured facially or lingually although the lingual cusps are taller. The cervical line is positioned occlusally approx.

3. LINGUAL ASPECT - MANDIBULAR FIRST MOLAR

a. From a lingual view the two taller more pointed lingual cusps will be seen. Since this tooth converges toward the lingual, a part of the outline of the distal cusp will be visible as well.

b. The mesiolingual cusp will usually be somewhat taller and a little wider than the distolingual cusp.

c. The lingual developmental groove extends a short distance onto this surface separating the two cusps but rarely if ever is deep enough to require restoration (i.e., not fissured).

d. The lingual surface of each cusp (lobe) is generally spheroidal in the occlusal half. The cervical half of the entire lingual surface is relatively smooth and flat.

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1.0 mm more so on the lingual surface than on the facial surface. Therefore, the root trunk measure-ment will also be 1 mm longer (average 4.0 mm) from cervical line to bifurcation on the lingual aspect of the tooth. It can also be said that when measured on the lingual, the total root length is greater because the roots are measured from the cervical line to the apex.

f. The surface of the root trunk is comparatively flatter than on the facial aspect. The developmental depression is deep at the bifurcation; however it quickly becomes progressively more shallow and fades out entirely before it reaches the cervical line.

4. MESIAL ASPECT - MANDIBULAR FIRST MOLAR

a. The crown outline from the mesial view is rhomboidal.

b. The greatest curvature of the facial outline is at the cervical third of the crown and is termed the cervical ridge. The crest is somewhat higher occlusally when compared to the cervical ridges found on maxillary molars but it is still in the cervical one-third.

c. The greatest curvature of the lingual outline is higher (occlusally) in the middle third of the crown.

d. Since mesial cusps are taller than the distal cusps of the tooth, only the mesiofacial and mesiolingual cusps will be visible from this view.

e. The fact that anatomical crown length measures the same facially and lingually is because of a slant in the level of the cervical line (it is higher occlusally at its lingual end). This also accounts for a longer root measurement along its lingual outline from the cervical line to apex.

f. The cervical line curves occlusally about 1.0 mm near the center of its mesial segment.

g. Only the mesial root is visible since it is wider faciolingually than the distal root and is usually a little longer.

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h. The mesial root apex is located directly below the mesiofacial cusp slightly facial to the faciolingual long axis bisector of the crown. This also contributes to a shorter, straighter facial root outline compared to a longer more slanted lingual outline.

i. The mesial root presents a rather wide develop-mental root depression extending the full length of the root. A similar depression will be found on the distal side of this same root as well. From both mesial and distal aspects, this root is convex at its facial and lingual borders with this broad concavity in between.

5. DISTAL ASPECT -MANDIBULAR FIRST MOLAR

a. From the distal view the crown outline is also rhomboidal.

b. It has already been noted that the distal cusp is located far enough around the distofacial line angle of the tooth to be considered partly on the distal surface. It is also obvious from the occlusal view that the facial surface converges to the lingual as it nears the distofacial line angle.

c. Therefore, from a distal view, the outline of the distal cusp will be seen superimposed on the distofacial cusp. Also, part of the facial surface of the crown will be visible.

d. The cervical line across the distal surface is relatively straight with little or no curve occlusally.

e. Both the mesial and distal roots will be visible from this view.

f. The distal root is narrower and shorter and the apex is more pointed than the mesial root; therefore, the outline of the mesial root will be evident beyond the outline of the distal root along at least one border.

g. There may be longitudinal root depressions on the mesial and distal aspects of the distal root. However, they are narrower faciolingually and not as deep as thosefound on the mesial root.

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NOTES:

1. Two roots (mesial & distal) that are wider in a faciolingual direction 2. Five cusps (three facial and two lingual) 3. MF groove separates the MF & DF cusps; DF groove separates the DF

and distal cusps 4. MF grooves terminates at the facial (buccal) pit 5. Mesial surface of the crown is concave in the cervical third and highly

convex at the upper two-thirds; the distal surface is convex throughout 6. Facial surface wider mesiodistally than the lingual surface (lingual

convergence) 7. Lingual groove separates two lingual cusps 8. Both mesial marginal ridge (longer) and distal marginal ridge (shorter) are

interrupted by developmental grooves 9. Crown outline is pentagonal (Wheeler describes it as hexagonal) 10. Three occlusal fossae: Central with central pit; extending from this pit are

the mesiofacial and lingual grooves and through it runs the central groove. The MTF and the DTF contain their respective mesial and distal pits which are termini for the central groove. The distofacial groove originates from the central groove, distal to the central pit.

11. Mesial and distal roots are joined at a common root trunk; both roots curve slightly to the distal and are blunt. The mesial root is the broadest (FL) of any root in the arch.

12. The mesial root is slightly larger than the distal root and has a distinct developmental root depression on its mesial and distal surfaces. This root has two pulp canals, one facial and one lingual.

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PERMANENT MANDIBULAR SECOND MOLAR

1. OCCLUSAL ASPECT - MANDIBULAR SECOND MOLAR

a. Average measurements: 1. Average mesiodistal diameter - 10.5 mm 2. Average buccolingual diameter - 10.0 mm 3. Average cervicoocclusal length of crown - 7.0 mm

b. All mandibular molars are wider in their mesiodistal

dimension. c. Greatest faciolingual measurement is usually in the

mesial half of crown. This is because the cervical ridge isusually more prominent on the mesiofacial lobe.

d. Although the crown outline is said to be rectangular, the crown tends to converge toward the distal. The distal outline is rather rounded (semi-circular) compared with a more square mesial outline.

e. The crown has four well developed cusps: two facial and two lingual. All four are of nearly equal size. The tips of the facial cusps (especially the mesiofacial cusp) are usually located farther lingually from the facial outline than is true of the tips of the lingual cusps in relation to the lingual outline.

f. The central groove crosses the occlusal surface mesiodistally slightly lingual to the faciolingual bisector. The facial groove and the lingual groove cross the central groove at right angles dividing the occlusal surface into mesial and distal halves. These three major grooves present a groove structure which is said to be a “+” or “cross” design. One author calls this a 4+ arrangement because there are 4 cusps of approximately equal size with a “+” sign dividing them.

g. There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual as well as a distofacial & distolingual groove at the proximal ends of the central groove. Also, there are often many supplemental grooves associated with the occlusal surface of this tooth.

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h. The central pit forms where the facial, lingual and central grooves meet and this is within the central fossa. The terminal ends of the central groove are in the mesial triangular fossa and the distal triangular fossa and each end has its respective mesial and distal pit.

i. Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that extends toward the central fossa. On most specimens the triangular ridges meet in such a way as to form two transverse ridges.

j. The mesial border of the occlusal table is the mesial marginal ridge and the distal border is the distal marginal ridge. The occlusal table is said to be rectangular.

g. The two roots are termed the mesial and distal roots. They vary greatly in length and divergence, but generally it may be said that (1) the mesial root will be longer than the distal root, (2) the roots are usually closer together than those of the first molar, (3) the roots may be fused together for all or part of their length; (4) the roots incline distally

2. FACIAL ASPECT - MANDIBULAR SECOND MOLAR

a. The crown is narrower mesiodistally and shorter occlusocervically than that of a mandibular first molar.

b. All four cusps will be visible since the lingual cusps are taller than facial cusps. Mesial cusps will be a little taller than distal cusps.

c. Lingual cusps are sharper and more pointed than facial cusps which are flatter and more rounded.

d. There is only one facial groove. It is simply called the facial (or “buccal”) groove. It separates the mesiofacial and distofacial cusps and extends only a short distance onto the facial surface. There is rarely a facial (buccal) pit at the termination of this groove.

e. The two facial cusps are about equal in mesiodistal width.

f. The cervical ridge is more prominent on the mesial half of the crown surface.

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more than those of the first molar, and (5) the root trunk will be shorter than that of the first molar.

3. LINGUAL ASPECT - MANDIBULAR SECOND MOLAR

a. The lingual convergence of the mandibular second molar is considerably less than that of the first molar; the lingual width measurement of the mandibular second molar may actually be wider than the lingual width measurement of the mandibular first molar of the same dentition.

b. Very little of the mesial or distal surfaces will be seen from a lingual view.

c. As was noted on the mandibular first molar, the crown length when measured from cusp tip to cervical line is about the same on both the facial and lingual surfaces. With the lingual cusps being taller, this is because the cervical line is higher (occlusally) on the lingual surface thereby producing equal measurements. This also makes the measurement of the length of both the root trunk and the total root length greater on the lingual aspect as measured from the cervical line.

4. MESIAL ASPECT - MANDIBULAR SECOND MOLAR

a. The greatest facial curvature is in the cervical one-third and is termed the cervical ridge.

b. The greatest lingual curvature is in the middle one-third.

c. The tips of the facial cusps are nearer the faciolingual long axis bisector than are the tips of the lingual cusps.

d. The facial cusps are shorter and more rounded. e. The lingual cusps are longer and more pointed. f. The mesial root is very similar in shape to the

mesial root of the mandibular first molar. The root depression and surface contour is also the same.

M D

F L

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NOTES:

1. Two roots, one mesial and one distal 2. Roots are wider in a faciolingual direction 3. Smaller than the mandibular 1st molar with four cusps (no distal cusp). 4. Only one facial groove separating the mesiofacial & distofacial cusps 5. Crown outline rectangular as is the occlusal table 6. Central pit located in the central fossa. The central groove, facial

groove and lingual groove all radiate from the central pit and form a characteristic “+” sign.

7. Central groove terminates mesially at the mesial pit, located in the MTF and distally at the distal pit located in the DTF.

8. There are no developmental grooves interrupting the marginal ridges 9. Roots are more distally inclined and closer together than the roots of

the mandibular 1st molar. 10. Mesial contact area with mandibular 1st molar: Middle ⅓ of the crown,

occlusocervically and faciolingually. 11. Distal contact area: Because the molars become progressively shorter

from the first to the third, the centers of the contact areas also drop cervically. A line bisecting the contact areas of the second and third molars is located approximately at the center of the middle thirds of the crowns. (Wheeler)

5. DISTAL ASPECT - MANDIBULAR SECOND MOLAR

a. The distal view of a mandibular second molar differs primarily from that view of a mandibular first molar in that the second molar has no distal cusp.

b. Otherwise, the contours of the crown and roots will be very similar. The lack of curvature in and the slanted position of the cervical line can be described the same as it was for the mandibular first molar.

c. The distal surface of the crown of the mandibular second molar is likely to be more rounded (convex) than that of the mandibular first molar. This often places the distal contact area (with the third molar) almost centered, both faciolingually and occlusocervically.

L F

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PRINCIPLE CHARACTERISTICS OF A

MANDIBULAR LEFT SECOND MOLAR

1. OCCLUSAL ASPECT a. Greatest faciolingual measurement at mesial half of crown because of

cervical ridge b. Four cusps of near equal size separated by “+” developmental grooves c. Three fossae: Central, MTF and DTF

2. BUCCAL ASPECT a. All four cusps visible (lingual cusps taller than facial cusps) b. Facial groove separates MF & DF cusps c. Cervical ridge is more prominent on mesial half of crown surface

3. LINGUAL ASPECT a. Taller more pointed lingual cusps b. Lingual convergence not a pronounced as that of mandibular 1st molar

4. MESIAL ASPECT a. Cervical ridge greatest facial curvature b. Greatest lingual curvature at middle third c. Facial cusps shorter and more rounded

5. DISTAL ASPECT a. Distal root slightly shorter than mesial root b. Distal contact centered occlusocervically and faciolingually

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PERMANENT MANDIBULAR THIRD MOLAR

1. OCCLUSAL ASPECT - MANDIBULAR THIRD MOLAR

a. Average mesiodistal crown diameter - 10 mm. b. Average faciolingual crown diameter - 9.5 mm. c. This tooth varies greatly in morphology and is second only

to the maxillary third molar in this respect. d. Most mandibular third molars crowns conform to the

characteristics of a mandibular second molar in the number and arrangement of the four cusps (Type I). They also present a “4+” groove pattern. Other mandibular third molars (Type II) will have five cusps and a groove pattern similar to a mandibular first molar. Both types will usually have a more rounded and narrower distal outline than either a mandibular first or second molar.

e. The occlusal anatomy often presents many supplemental grooves radiating from the basic developmental grooves.

f. Mesial conatact area: Center of the middle 1/3

2. FACIAL ASPECT - MANDIBULAR THIRD MOLAR

a. The crown from the facial aspect will present either two facial cusps (similar in relative size and placement to those of the mandibular second molar) or three cusps (similar in relative size and placement to those of the mandibular first molar).

b. Facial and lingual cusps are likely to be more nearly the same height on third molars.

c. Facial (buccal) grooves are not likely to be deep or fissured.

d. The typical third molar will have two roots (mesial and distal). These will usually be shorter and curved more toward the distal with a higher degree of inclination relative to the occlusal plane. The roots may be separated or fused for all or part of their length.

e. Mesial contact area: Center of the middle 1/3

M D

D M

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3. LINGUAL ASPECT - MANDIBULAR THIRD MOLAR

From the lingual aspect it will be noted that the lingual cusps are likely to be more pointed than facial cusps. Otherwise, this surface presents a relatively smooth and convex contour.

4. MESIAL ASPECT - MANDIBULAR THIRD MOLAR

a. The mesial view resembles that of the mandibular second molar except that the facial and lingual cusps are more nearly the same height. Accordingly, the cervical line crosses the surface more horizontally.

b. The roots are shorter; therefore, the facial and lingual outlines converge at a faster rate toward the apex. The root apex is more pointed.

5. DISTAL ASPECT - MANDIBULAR THIRD MOLAR

The anatomical appearance from the distal aspect will be somewhat similar to the distal view of either a mandibular second molar or a mandibular first molar except for the size and length of the root. Also, variations will occur depending on whether the tooth has four or five cusps.

F L

M D

L F

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6. SPECIAL NOTATIONS REGARDING THIRD MOLARS

a. Third molars, because of their late development

and position in the dental arch, often become trapped in the bone or have their normal eruption pathway impeded by other teeth. The general term for this situation is “impaction”. Because of this, the pressure on the developing tooth follicle may lead to rather bizarre variations in the third molar’s shape and size.

b. It is not uncommon to see a disproportion in the size of third molar crowns and the sizes of their roots. When crowns and/or roots are so out of proportion as to be considered malformed, it is more likely to see a mandibular third molar with an exceptionally large crown associated with very small, short, and fused roots while on the other hand, a maxillary third molar under similar circumstances will present an exceptionally small crown that will have normal size, well developed, and divergent roots.

NOTES:

1. Mandibular third molars are highly variable in their morphology 2. They may resemble mandibular 1st or 2nd molars but are usually

much shorter and more bulbous 3. Crown outline and occlusal table are ovoid 4. Roots are short, sometimes fused and distally inclined 5. Because the molars become progressively shorter from the first to

the third, the centers of the contact areas also drop cervically. A line bisecting the contact areas of the second and third molars is located approximately at the center of the middle thirds of the crowns. (Wheeler)

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PRINCIPLE CHARACTERISTICS OF A MANDIBULAR LEFT THIRD MOLAR

OCCLUSAL ASPECT a. Ovoid shape b. Type I: “4+” groove pattern c. Type II: 5 cusps resembling mandibular 1st molar

BUCCAL ASPECT a. Single facial groove b. Cusps equal in height c. Short, distally inclined roots

LINGUAL ASPECT a. Lingual surface relatively smooth with a convex contour b. Short, distally inclined roots

MESIAL ASPECT a. Facial & lingual cusps essentially the same height b. Short root with facial & lingual aspects rapidly converging

toward the apex

DISTAL ASPECT a. Facial & lingual cusps essentially the same height b. Short root with facial & lingual aspects rapidly converging

toward the apex

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NUMBER OF ROOTS – PERMANENT DENTITION One Maxillary and mandibular central incisors Maxillary and mandibular lateral incisors Maxillary and mandibular canines Sometimes maxillary first premolar Maxillary second premolar Mandibular first and second premolars Sometimes maxillary and mandibular third molars (when fused) Two Usually maxillary first premolar Sometimes maxillary third molars Mandibular first and second molars Generally mandibular third molars (when not fused) Three Maxillary first and second molars Generally maxillary third molars Sometimes mandibular third molars which can have up to eight terminal roots.

NUMBER OF CUSPS – PERMANENT DENTITION One cusp Maxillary and mandibular canines Usually mandibular first premolar has only one functioning cusp Two cusps Maxillary first and second premolars Mandibular first premolar Sometimes mandibular second premolar (2-cusp variety) Three cusps Sometimes mandibular second premolar (3-cusp variety) Sometimes maxillary third molars Four cusps Maxillary and mandibular second molars Sometimes maxillary and mandibular third molars Five cusps Maxillary* and mandibular first molars Sometimes maxillary second molars* Sometimes mandibular third molars *The fifth cusp, which is also known as the cusp of Carabelli or perhaps more properly as Carabelli’s tubercle, is found on the lingual surface in the mesial portion of the permanent maxillary 1st molar augmenting the mesiolingual cusp. It is rarely but sometimes found on the permanent maxillary 2nd molar as well. NOTE: The permanent tooth with the greatest overall average length is the maxillary canine.

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DENTAL ANATOMY Compendium of Key Points

Charles J. Arcoria, D.D.S., M.B.A.

1. The formula for the primary dentition per maxillary/mandibular quadrant: i 2/2; c 1/1; m 2/2

2. The formula for the permanent dentition per maxillary/mandibular quadrant:

I 2/2; C 1/1; P 2/2; M 3/3

3. Contact areas: A. Anterior teeth (incisocervically):

Maxillary Mesial Distal Central incisor Incisal ⅓ Junction of Incisal & Middle ⅓ Lateral incisor Junction of Incisal & Middle ⅓ Middle ⅓ Canine Junction of Incisal & Middle ⅓ Middle ⅓ Mandibular Central incisor Incisal ⅓ Incisal ⅓ Lateral incisor Incisal ⅓ Incisal ⅓ Canine Incisal ⅓ Middle ⅓

Maxillary anterior teeth: IJ JM JM Mandibular anterior teeth: II II IM B. Posterior teeth (occlusocervically):

1. As a generality, the proximal contact areas of all posterior teeth are positioned in the middle ⅓ of the crown occlusocervically. The mesial contact area is typically positioned more occlusally than the distal. The contact areas are ovoid, slightly wider in a faciolingual dimension.

2. EXCEPTIONS: (a) The mesial contact area of the mandibular 1st premolar is

positioned more cervically (sloped MMR) than the distal. (b) The contact areas on the mesial surfaces of maxillary &

mandibular molars are located at the junction of the occlusal & middle ⅓

C. Faciolingual: All teeth have faciolingual proximal contact areas located in the middle ⅓ of the crown however the posterior teeth tend to have theirs positioned slightly more toward the facial.

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4. Heights of Contour: A. All teeth generally have facial heights of contour at the cervical ⅓ of

the crown although the mandibular molars are more correctly described as being at the junction of the cervical and middle ⅓.

B. Facial heights of contour are also termed “cervical ridges” and extend in a mesiodistal direction parallel to the cervical line (CEJ).

C. Facial heights of contour are most prominent on mandibular posterior teeth. They are least prominent on mandibular anterior teeth.

D. Anterior teeth have lingual heights of contour at the cervical ⅓ of the crown, also termed “cervical ridges”

E. Posterior teeth have lingual heights of contour at the middle ⅓ of the crown. EXCEPTION: Mandibular 2nd premolar- the lingual ht. of contour is said to be at the occlusal ⅓ (due to the diminished lingual crown height and cusp size).

5. CEJ (cementoenamel junction aka the cervical line): A. Dips incisally/occlusally on the proximal surfaces of teeth. B. Dips more so on anterior teeth than posterior teeth. C. Dips more so on the mesial proximal surface than on the distal. D. Dips more so on maxillary teeth than on mandibular. E. Based on the above criteria, the most severe curvature would be found on the mesial surface of the maxillary central incisor and the least would be on the distal surface of the mandibular 3rd molar. 6. Embrasures:

A. There are 4 V-shaped spaces (embrasures) around every tooth contact area: occlusal (incisal), lingual, gingival and facial.

B. Lingual embrasures are wider than facial embrasures on all permanent teeth because of faciolingual convergence (generally teeth are wider facially than they are lingually). There are three exceptions: (1) the maxillary 1st molar and (2) the 3-cusp variety mandibular 2nd premolar because the lingual calibration on these two teeth is greater than it is on the facial. (3) The mandibular central incisors are the other exception where the facial and lingual embrasures are described as being the same size.

C. Incisal embrasure: (1) largest is between maxillary lateral incisor & canine (2) 2nd largest: between mandibular lateral incisor & canine (3) 3rd: between maxillary central & lateral incisors (4) 4th: between maxillary central incisors (5) 5th: between mandibular central & lateral incisors (6) 6th (smallest) incisal embrasure is between the mandibular

central incisors. D. Largest overall occlusal embrasure: between maxillary canine and 1st

premolar.

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7. Calcification & Eruption dates: A. Primary teeth:

(1) show first evidence of calcification in utero during the 2nd trimester (~14 weeks).

(2) calcification of crowns complete by 11 months (maxillary 2nd molars)

(3) mandibular teeth usually erupt before their maxillary counterparts

(4) mandibular central incisors first to erupt (10 months), maxillary 2nd molars are last (29 months)

(5) all roots have completed formation by 39 months (maxillary canines)

(6) see Calcification and Eruption charts (pp. 26-27) for chronologies

B. Permanent teeth:

(1) 1st molars are the first permanent teeth to initiate calcification and do so after birth.

(2) mandibular teeth usually erupt before their maxillary counterparts except the maxillary 2nd premolar which may erupt at the same time or before the mandibular 1st premolar

(3) 1st molars are the first permanent teeth to erupt (6 yrs. of age). This initiates the “mixed dentition” phase of development.

(4) mandibular central incisors are the first succedaneous permanent teeth to erupt (6-7 yrs. of age)

(5) maxillary canines are the last succedaneous permanent teeth to erupt

(6) 3rd molars last teeth to initiate calcification (9 yrs.), also last to complete crown formation and erupt

(7) see Calcification & Eruption charts (p. 23) for chronologies 8. Geometric Forms of Teeth:

A. Facial or Lingual view: All teeth TRAPEZOIDAL with the shorter parallel side oriented cervically (gingivally).

B. Proximal view: (1) Anterior teeth: TRIANGULAR with the apex oriented incisally (2) Maxillary posterior teeth: TRAPEZOIDAL with the shorter

parallel side oriented occlusally (3) Mandibular posterior teeth: RHOMBOIDAL

9. Anterior teeth incisal edge orientation (proximal view): A. Maxillary:

(1) Incisors: centered over the long-axis bisector of the tooth (2) Canines: cusp tip is centered over or slightly facial to the long

axis bisector of the tooth (never lingual)

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B. Mandibular: (1) Incisors: lingual to the long-axis bisector of the tooth (2) Canines: lingual to the long-axis bisector of the tooth

10. Teeth with one facial cusp: the mesial cusp ridge is slightly shorter than the distal cusp ridge. EXCEPTIONS: (1) maxillary 1st premolar and (2) primary maxillary canine.

11. Crowns of teeth when measured occlusocervically tend to get shorter from

the canine to the 3rd molar.

12. Developmental lobes: All teeth develop from 4 lobes. EXCEPTIONS: (1) permanent maxillary 1st molar, (2) permanent mandibular 1st molar, and (3) 3-cusp mandibular 2nd premolar (all exceptions develop from 5 lobes).

13. Generally, the mesial portion of a tooth is better developed and measures

more occlusocervically as well as cervicoapically than does the distal portion

14. When comparing like classifications of teeth (i.e. molars or premolars) the more posterior the tooth, there is the likelihood for it to have more supplemental anatomy, sometimes termed “tertiary anatomy” (supplemental ridges, grooves, etc.).

15. The largest cusp on molars will be the mesial supporting cusp (maxillary:

ML; mandibular: MF

16. Roots, canals and pulps: A. The roots of all teeth are inclined distally. B. If a single root has two canals, they will be oriented one facial and one

lingual C. Teeth erupt with as many pulp horns as they have cusps. The pulp

chamber follows the overall outline of the crown so its widest portion will correlate to the widest portion of the crown.

D. Single molar roots with more than one canal: (1) Maxillary 1st molar (MF root) (2) Mandibular 1st molar ( M root) (3) Mandibular 2nd molar (M root) (4) Distal roots of Mandibular 1st (31.6%) & 2nd (14.9%) molars

E. Single anterior roots with tendencies for more than one canal: (1) Mandibular canine (most likely anterior tooth); has M & D root

depressions and is also the anterior tooth most likely to have a bifurcated root

(2) Mandibular lateral incisor (next most likely, has M & D root depressions)

(3) Mandibular central incisor (rarely & least likely, has M & D root depressions)

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(4) NOTE: Maxillary anterior teeth do not have multiple canals F. Maxillary premolars:

(1) 1st: Two canals (always) and two roots (usually); F & L, rarely 3 but if so, MF, DF & L

(2) 2nd: Variant pulp morphology can have 2 canals and occasionally 2 roots.

G. Premolar most likely to have one root and one canal: Mandibular 2nd

H. Only tooth with a pulp wider mesiodistally than faciolingually: maxillary central incisor I. Maxillary central & lateral incisors: Significant faciolingual taper, hence the pulp chambers are triangular when viewed incisally in cross section.

17. Individual Tooth Morphology Unique Characteristics:

A. Maxillary Central Incisor (1) M-D crown dimension greatest of any anterior tooth (2) M curvature of cervical line toward the incisal greatest of any

tooth (3) Incisal ridge centered labiolingually

B. Maxillary Lateral Incisor (1) M-D crown dimension smallest of any maxillary tooth (2) Tooth with most developmental anomalies (exempting 3rd

molars) (3) Most cervically located contact area of any incisor (centered

distal contact area) (4) M-D (6.5 mm) and F-L (6.0 mm) dimensions closer than any

other anterior tooth (5) Incisal ridge centered labiolingually

C. Mandibular Central Incisor (1) Crown dimensions smallest of any tooth (2) Bilaterally symmetric crown (3) Proximoincisal line angles sharpest of any tooth (shared with

MI line angle of maxillary lateral incisor) (4) Proximal contact areas at the same level (incisal ⅓) (5) Incisal edge lingual to faciolingual bisector (shared with all

mandibular anterior teeth) (6) Unique characteristics shared with mandibular lateral incisor:

(a) fewest facial developmental depressions, lines & grooves (b) smoothest lingual surface contours (c) least developed cingulum

D. Mandibular Lateral Incisor (1) Crown “twisted” on root; seen from two views:

(a) Mesial: can see lingual portion of DMR (b) Incisal: from mesial → distal, incisal ridge curves lingually

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(2) Shared unique characteristics with mandibular central incisor: See C-5 and C-6 above

(3) MI line angle sharp; DI less so

E. Maxillary Canine (1) Greatest (along with mandibular canine) overall tooth length (2) Longest root length of any tooth (3) F-L dimensions greatest of any anterior tooth (4) Distal bulge (pinched or stretched distally) (5) Cusp tip centered with or facial to faciolingual bisector (never

lingual) (6) Greatest cervical prominence of any anterior tooth (7) Facial ridge prominence greatest of any anterior tooth (8) Distal contact area centered F-L and C-I

F. Mandibular Canine (1) Greatest (along with maxillary canine) overall tooth length (2) Longest root length of any mandibular tooth (3) I-C crown length greatest of any tooth (4) Mesial crown & root surfaces aligned in a straight line (5) From proximal view: facial crown and root curvature “C”

shaped (6) Cusp tip/incisal edge lingual to faciolingual bisector (shared

with all mandibular anterior teeth (7) ML & DL fossae each have distinct boundaries with the lingual

ridge being common to both and the cingulum being the most cervical boundary of each

G. Maxillary 1st Premolar

(1) Only premolar with mesial cusp ridge longer than distal cusp ridge (facial cusp)

(2) Mesial marginal ridge (developmental) groove (3) Mesial crown concavity (4) Mesial root depression (5) L cusp 1.0 mm shorter than F cusp (6) Deep central developmental groove

H. Maxillary 2nd Premolar (1) More bilaterally symmetrical than any other posterior tooth (2) Cusp heights closer than any other premolar (3) M and D fossae closer to one another than any other posterior

tooth

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I. Mandibular 1st Premolar (1) Presence of ML groove (unique, only tooth to have this

developmental groove) (2) F-L crown dimension smallest of any posterior tooth and the

same as the mandibular canine (7.5 mm) (3) FL (7.5 mm) – MD (7.0 mm) crown dimensions closer than any

other mandibular tooth hence occlusal crown form is said to be diamond shaped

(4) M contact area cervical to D contact area (5) Sloped occlusal surface visible from lingual aspect (6) M marginal ridge slopes lingually (45°) and is cervical to D

marginal ridge (7) L cusp is small, non-functional and almost cingulum-like

J. Mandibular 2nd Premolar (1) Two varieties:

(a) 2-cusp: “U” or “H” occlusal groove pattern (b) 3-cusp: “Y” occlusal groove pattern & more common

(2) 3-cusp only premolar with multiple lingual cusps and develops from five lobes

(3) 3-cusp only premolar with a lingual groove (4) 3-cusp only premolar with a central fossa (5) 3-cusp premolar and maxillary 1st molar only permanent teeth

where the lingual calibration measures greater than facial, i.e. the crown does not taper faciolingually

(6) 3-cusp premolar L height of contour in occlusal ⅓ of crown (7) 3-cusp premolar most likely premolar to be congenitally missing

K. Maxillary 1st Molar (1) This tooth and the 3-cusp variety mandibular 2nd premolar are

the only permanent teeth where the mesiodistal lingual calibration is greater than on the facial

(2) 5th cusp (Carabelli) augments lingual surface of the ML cusp (3) Oblique ridge (all maxillary molars) formed by the distal cusp

ridge of the ML cusp and the triangular ridge of the DF cusp (4) Primary cusp triangle (all maxillary molars): MF, DF & ML

cusps (5) Centered distal contact area

L. Maxillary 2nd Molar (1) 4 primary cusps, rarely a 5th cusp (2) Diminished DL cusp size, primary cusp triangle remains (3) Centered distal contact area (4) Oblique ridge (all maxillary molars)

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M. Maxillary 3rd Molar (1) Smallest OC crown dimension of any tooth (2) Shortest root(s) of any maxillary tooth (3) More distal inclination of roots of any maxillary tooth (4) Primary cusp triangle present (heart shaped crown) or may

have vestige of DL cusp (talon) (5) Multiple supplemental ridges & grooves (6) Oblique ridge (all maxillary molars)

N. Mandibular 1st Molar (1) Largest M-D crown dimension of any tooth (11.0 mm) (2) Largest F-L crown dimension of any mandibular tooth (10.5

mm) (3) Largest O-C crown dimension of any mandibular molar (4) Longest root length of any molar (14.0 mm) (5) Greatest mesiodistal root separation of any tooth (6) M root has greatest F-L dimension of any root (7) Only tooth with two facial developmental grooves

O. Mandibular 2nd Molar (1) Characteristic MF crown prominence (2) Characteristic “+” shaped occlusal groove pattern (3) All cusps of “near” equal size (4) Centered distal proximal contact (along with maxillary lateral

incisor, canine, 1st molar and 2nd molar)

P. Mandibular 3rd molar (1) Smallest OC crown dimension of any mandibular tooth (2) More bulbous crown form than any other mandibular tooth (3) More distal root inclination than any other mandibular tooth (4) Shortest root(s) of any mandibular teeth (5) Multiple supplemental ridges & grooves

18. Widest, narrowest, tallest, longest, etc;

A. Widest tooth mesiodistally: mandibular 1st molar B. Widest primary tooth mesiodistally: mandibular 2nd molar C. Widest anterior tooth mesiodistally: maxillary central incisor D. Widest tooth faciolingually: maxillary 1st molar E. Widest primary tooth faciolingually: maxillary 2nd molar F. Widest anterior tooth faciolingually: maxillary canine G. Only tooth with a pulp chamber wider mesiodistally than faciolingually:

maxillary central incisor H. Only teeth to measure wider lingually than facially:

(1) primary maxillary 2nd molar (2) permanent maxillary 1st molar (3) 3-cusp variety mandibular 2nd premolar

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19. Longest teeth (from cusp tip to root tip): (1) maxillary canine & (2) mandibular canine (both 27.0 mm)

20. Longest root (CEJ to apex): maxillary canine (17.0 mm)

21. Tallest crown incisogingivally:

(1) mandibular canine (11.0 mm) > (2) maxillary central incisor (10.5 mm) > (3) maxillary canine (10.0 mm)

22. Anomalies:

A. Maxillary lateral incisor (other than the 3rd molars, most common permanent tooth to have anomalies)

(1) dens in dente (2) congenitally missing (2nd most common tooth) (3) microdontia (4) peg lateral (5) supernumerary

B. Mesiodens: most common incident of a supernumerary tooth (between maxillary central incisors)

C. Mandibular 2nd premolar: most likely premolar to be congenitally missing

D. 3rd molars: most common teeth to be congenitally missing or malformed.

23. Tooth with the smallest anatomical crown: mandibular central incisor 24. Anterior tooth with the most symmetrical anatomical crown: mandibular central

incisor

25. Posterior tooth with the most symmetrical anatomical crown: maxillary 2nd premolar

26. Tooth with the narrowest M-D measurement: mandibular central incisor

27. Tooth with the best developed lingual anatomy: maxillary lateral incisor

28. Only tooth with a linguogingival groove: maxillary lateral incisor

29. Only tooth with a mesiolingual groove: mandibular 1st premolar

30. Only tooth with a mesial marginal developmental groove: maxillary 1st premolar (maxillary molars may have supplemental marginal grooves)

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31. Smallest facial embrasure in the mouth or the smallest lingual embrasure in the mouth is between the two mandibular central incisors. It should be noted that they are essentially of equal size.

32. Concrescence: The cementum of two proximal teeth is fused together. When

seen, usually associated with 2nd & 3rd molars as well as anterior teeth.

33. Impacted teeth: Most frequently seen in (1) 3rd molars, (2) maxillary canines and (3) mandibular 2nd premolars

Intraoral Exam on Student Partners

The goal of this introductory exercise is to gain familiarity with basic structures

and landmarks within the oral cavity. Label the provided diagram for reference. Students should pair up as assigned. Perhaps you will make a new friend. As you proceed with the exercise, please make sure that everyone has an opportunity to benefit from being both the “doctor” and the “patient”.

It is important to observe guidelines for infection control and patient con-sideration when performing the examination. Wash your hands and put on latex gloves for the exam. Use a sterile exam package for the examination.

The doctor should stand for this exam, while the patient should be seated.

Even with the mouth closed, the vermilion border of the lips and the labial

commissures may be observed.

When the patient opens their mouth, identify the maxillary (upper) and the mandibular (lower) dental arches.

Identify the right side and the left side of both arches. Note that this refers to the

patient’s right or left side, not the observer’s. Identify the midline of both arches. This is an imaginary line between the central incisor teeth and it divides each arch into a left quadrant and a right quadrant.

Label on the diagram the four quadrants of the oral cavity. (maxillary right

quadrant, mandibular left quadrant, etc.) Identify the incisor teeth. (Centrals and laterals) Identify the canine teeth. Identify the premolar teeth (sometimes referred to as bicuspids) Identify the molar teeth. How many of each type of teeth are present in the complete adult dentition? Incisors_____ Canines_____ Premolars_____ Molars_____

On the diagram provided, place an “X” through any missing teeth. Sketch in any restorations (completed dental procedures), which are present.

The vestibule is the space adjacent to the cheeks near the roots of the teeth that surrounds the maxillary and mandibular arches. Essentially this space is formed where the cheeks meet the maxilla or mandible. Located within the vestibule are the frena (pl) (sing. = frenum). They are muscle attachments that also aid in facial expression. Find them near the midline and near the premolars.

L-1

Notice the mucosa that lines the oral cavity. This is a moist and slippery tissue as

compared to the vermillion border of the lips. On the mucosa that lines the patient’s cheek, notice the opening of the parotid

salivary duct located near the maxillary molars. What are some possible advantages and disadvantages of salivary flow? Also located on the buccal mucosa is a demarcation called the linea alba (white line). This whitish line parallels the plane of the biting surfaces of the molars and premolars. Had you noticed this prior to today? Do you have any ideas as to how this line originated?

The mucosa gives way to gingiva (gum tissue) along the lateral portions of the mandible and the maxilla. Take note of the mucogingival junction that demarcates these two distinctive types of tissue. What is the major change in the tissue that is responsible for this obvious change in color?

Located on the gingiva near each tooth is a more subtle line or depression called the free gingival groove. What does it delineate?

The gingiva located immediately adjacent to the teeth has special names reflective of its location. Can you differentiate between marginal and interdental gingiva?

Just behind the mandibular molars notice the retromolar pad. This is soft, depressible tissue.

Now looking towards the throat, attempt to locate the palatine tonsils. There

may be great variation in the amount of this tissue that is present. Your patient has possibly had this tissue removed. Do you know the function of this tissue?

The “roof” of the mouth is referred to as the palate. Near the maxillary central incisors is a landmark called the incisive papilla. Behind this are several rough folds of tissue called rugae. The rugae are important because the tongue moves across this area during the pronunciation of many different syllables. Near the back end of the palate is a curious structure called the uvula. Do you know the function of this structure?

In the “floor” of the mouth, find the sublingual caruncle which is the opening for the mandibular salivary duct. It is located in the midline behind the mandibular incisors. Be careful when viewing this structure as you might get “gleeked”.

Finally, take a closer look at the tongue. The tongue shows a great deal of variation from one person to the next. Notice that it fills whatever space is available. Perhaps the tongue is scalloped and conforms to the shapes of the teeth surrounding it. This powerful muscle can be deeply fissured, or may be quite smooth.

This concludes today’s tour of the oral cavity!

L-2

L-3

L-4

Linea Alba

L-5

L-6

L-7

Lecture Seat No. _________

Name: ______________________________________

IN

1. SHAW–1: Large wax dr wax from its source to th homogenous conflux. 2. SHAW-2: Small wax dro 3. SHAW-4: Spatula/Carvits source to the carving. T carving tool for certain a strokes. 4. SHAW-7: Double-ended The larger end, once he 5. PKT-4: Double ended c “bow” to allow access fo

il d t h

Begin to develop

throughout your profesinstructor demonstrate tapply wax as well as cargive you much more coninstruments exactly whe

Suggested Exercis 1. Write your name in wax 2. Create three standard

geometric forms (squarcircle, triangle) in wax.

Try using different colo of wax. 3. Be creative with the waxes. Draw a picture, write a poem, etc. Extr credit for 3 – dimension forms!

KNOW YOUR WAXING INSTRUMENTS

opper. Double-ended (one end slightly larger). Once heated, used to carry e carving. Also used to coalesce wax from multiple applications into a

pper. Same as above, only with smaller amounts of wax.

er. Once heated, one end can be used to carry larger amounts of wax from

he pointed end of the spatula allows this instrument to also be used as a pplications. The other end is designed to carve the wax in gentle pulling

spatula. The smaller end is very similar to the spatula end of the SHAW-4. ated, can carry larger amounts of wax from its source to the carving.

arver. Each end is set at 90 degrees to the other. One end has a noticeable r unique applications. This carving instrument has sharper edges and will

k th l h dl d d li t l

goodsional o you tve youtrol wi

re you

es

e, rs

a al

LABORATORY EXERCISE #1

TRODUCTORY WAXING EXERCISE

IMPORTANT

hand skills and techniques early that will serve you now andcareer. The first skill to learn is the finger-rest. Have your he proper way to stabilize your hands as you heat, transfer andr wax patterns. These skills will soon become automatic to you,th your hands, and provide you an easier means of placing yourwant them to go.

Excellent Good Needs minor improvement

Unacceptable

Creativity

Enthusiasm

Finish and Polish

Neatness of project

Project complete & on time

FINAL GRADE: Pass Fail

INSTRUCTOR _________________________

L-8

Name __________________________________ Lecture Seat No. __________

LABORATORY EXERCISE #2 Stone Casts

Identify the following Morphological Characteristics on the stone casts provided. Using an

identifying characteristic color, mark the crests of ridges, the depths of grooves or outline of a specific area. The same color may be used to identify more than one non-related characteristic (i.e., red may be used to identify one of the grooves as well as one of the ridges or one of the line angles.) A. On the teeth in the maxillary right and mandibular left quadrants identify the

following negative anatomical characteristics: Name of Morphological Characteristic Sample of Color Used 1. CENTRAL fossa ________________________

2. MESIAL TRIANGULAR fossa ________________________

3. DISTAL TRIANGULAR fossa ________________________

4. MESIAL LINGUAL fossa ________________________

5. DISTAL LINGUAL fossa ________________________

6. LINGUAL fossa ________________________

7. CENTRAL groove ________________________

8. FACIAL (Buccal) groove ________________________

9. LINGUAL groove ________________________ B. On the teeth in the maxillary left and mandibular right quadrants identify the

following positive anatomical characteristics: Name of Morphological Characteristic Sample of Color Used 1. Tip of each CUSP ________________________

2. Each INCISAL RIDGE and EDGE ________________________

3. Each MESIAL CUSPAL RIDGE ________________________

4. Each DISTAL CUSPAL RIDGE ________________________

5. Each MESIAL MARGINAL RIDGE ________________________

6. Each DISTAL MARGINAL RIDGE ________________________

7. Each TRIANGULAR RIDGE ________________________

8. Each CERVICAL RIDGE ________________________

9. Each BUCCAL (Facial) RIDGE ________________________

10. Each LINGUAL RIDGE ________________________

11. Each LABIAL (Facial) RIDGE ________________________

12. Each CINGULUM ________________________

13. Each TRANSVERSE RIDGE ________________________

14. Each OBLIQUE RIDGE ________________________

L-9

Instructor: _________ Grade:_________

Name __________________________________ Lecture Seat No. __________

L-10

C. As briefly as possible answer the following questions:

1. Which teeth have a central fossa?

2. Which teeth have mesial and distal triangular fossae?

3. Which teeth have mesial and distal lingual fossae?

4. Which teeth have a single lingual fossa? 5. Which teeth have lingual grooves?

6. Which teeth have facial (buccal) grooves?

7. Which teeth have central grooves?

8. Which teeth have incisal ridges? What is an incisal edge?

9. Which teeth have cuspal ridges?

10. Which teeth have facial ridges?

11. Which teeth have lingual ridges?

12. Which teeth have marginal ridges?

13. Which teeth have triangular ridges?

14. Which teeth have transverse ridges?

15. Which teeth have oblique ridges?

16. What are the boundaries of an occlusal table?

17. Which teeth have an occlusal table?

18. What are the boundaries of the lingual fossa on an incisor? 19. What are the boundaries of the distal lingual fossa on a canine?

20. Which teeth have a cingulum (pl = cinguli)?

21. Which teeth have a cervical ridge? Which teeth have more than one cervical

ridge? Where are they located?

Lecture Seat # __________________

1. Incisal Anatomy a. Incisal ridge (edge):

(1) Distal portion tapers or slants cervically from mesial to distal

(2) Distal portion also curves lingually, i.e. the distal end of the ridge is more lingual than the mesial. This view gives the crown a “twisted” or “rotated” appearance

b. Line angles (1) MI is more square (2) DI is slightly rounded

c. M & D proximal contacts are within incisal 1/3 of crown 2. Facial (Labial) Anatomy

a. Incisal edge has a subtle slope from M-D b. Developmental depressions (denoting formative lobes) are faint but present c. Line angles: see above d. Proximal contacts are both within the incisal 1/3 of the crown 3. Lingual Anatomy a. Marginal ridges: subtle but present b. Lingual fossa: shallow & limited to incisal 1/3 c. Cingulum smoothly rounded and not prominent or well defined 4. Mesial:

a. Incisal ridge lingual to faciolingual long-axis bisector b. Part of the distal marginal ridge is visible because of its lingual twist

5. Distal: a. Incisal ridge well lingual to faciolingual long-axis bisector b. Mesial marginal ridge is not visible

F L

L-11

F L F

D

M D

F M D

L

D

Laboratory Project: PJ-01

Tooth # 26- Cut-Out

Lecture Seat # _________________

1. O

2. T

3. M

4. M

Laboratory Project: PJ-02Tooth #12- Cut-Out

M D

L F L

F

M D

L

M M

F L

cclusal Anatomy a. Crown outline is “hexagonal” b. MF & DF line angles are relatively square c. Line angles “mirror” line angles of abutting teeth d. ML & DL line angles more rounded e. Central groove: crosses occlusal table mesiodistally parallel to but slightly lingual to the crown’s faciolingual bisecting line. f. Central groove connects M & D triangular fossae g. Crest of lingual ridge well mesial of M-D bisector h. Facial cusp: 1) is distal to M-D bisector, i.e mesial cuspal ridge is longer than the distal cuspal ridge 2) The mesial end of the mesial cuspal ridge is more lingual than the distal end of the distal cuspal ridge.i. Lingual cusp: 1) Is mesial to the M-D bisector, i.e the mesial cuspal ridge is shorter than the distal cuspal ridge 2) Cuspal ridges meet at cusp tip as a continuous curve

riangular Ridges a. From facial cusp & lingual cusp meet near center of occlusal table but slightly lingual of a FL bisector of the crown b. Although separated by a deep central groove, potential for a true transverse ridge to form arginal Ridges:

a. Mesial: 1) Meets the mesial cuspal ridge of the facial cusp at at a near 90 degree angle 2) Mesial marginal developmental groove crosses ridge at its center 3) Crest is almost perpendicular to the faciolingual long axis bisector b. Distal: 1) Longer than mesial and uninterrupted by a groove 2) Meets the distal cuspal ridge of the facial cusp at an acute angle

esial Aspect: a. Crown outline is trapezoidal b. Can see height of contour: 1) Facial: cervical 1/3 (cervical ridge) 2) Lingual: middle 1/3

c. Mesial marginal developmental groove is evident as it crosses thru the mesial marginal ridge d. The cervical line curves occlusally in its middle segment approx.1.0 mm. e. Proximal Contact: located just cervical to the mesial segment of the mesial marginal ridge, facial to the mesial marginal developmental groove. f. Mesial developmental root depression: 1) Crosses the cervical line and extends to the level of the junction of the cervical & middle thirds of the crown. 2) At the level of the cervical line, the tooth surface will be convex in its facial and lingual thirds and concave in its middle third.

L-12

Lecture Seat # ____________________

Laboratory Project: PJ-04Tooth #19- Cut-Out

1. Occlusal Anatomy a. Cusps:

1) MB (largest), DB, ML (tallest), DL (2nd tallest) 2) Distal cusp: smallest cusp and is located at or slightly lingual to the DB line angle 3) Buccal cusps are more rounded, lingual cusps more pointed

b. Triangular ridges: each cusp has one but none meet, i.e. no transverse ridges c. Cuspal ridges: flow into the marginal ridges at the perimeters d. Fossae:

1) Central 2) Mesial triangular 3) Distal triangular

e. Developmental grooves: 1) Central

2) Mesiobuccal 3) Distobuccal 4) Lingual

f. Crown converges lingually, i.e. buccal half is wider than lingual half g. Contact areas: both mesial & distal located buccal to a line bisecting the crown into buccal & lingual halves.

1) Mesial: 1 mm cervical to the marginal ridge

2) Distal: 1 mm cervical to the distal cuspal ridge of the distal cusp

3) Line angles “mirror” line angles of abutting tooth

2. Buccal aspect:

a. Trapezoidal with parallel sides at occlusal & cervical b. All cusps visible (lingual cusps taller) c. MB cusp widest of the buccal cusps and its cuspal ridges meet at very obtuse (almost flat) angle. d. DB cusp almost as wide as MB cusp & cuspal ridges meet at a more significant angle e. Distal cusp is the smallest and although rounded, is more pointed than the other buccal cusps. f. Two buccal grooves: MB & DB (longer of two) g. Cervical ridge at the cervical third of the buccal surface of the crown (mesial 2/3 only)

3

4

5

L-13

. Lingual Aspect:

a. ML cusp slightly taller & wider than DL cusp b. Lingual developmental groove visible c. Height of curvature will be at the middle 1/3

. Mesial aspect:

a. Crown outline is rhomboidal b. Can see the height of contour:

1) Buccal- cervical 1/3 (cervical ridge) 2) Lingual- middle 1/3

c. Proximal contacts: 1 mm cervical to the marginal ridge on the buccal ½ of the crown

. Distal aspect: a. Crown outline is rhomboidal b. Distal cusp position may be slightly lingual to

the DF line angle, i.e., the distal contact is 1 mm below the distal cuspal ridge of the distal cusp.

M D D M

M D

L F L

B

D M L

B L

Laboratory Project: PJ-03 Tooth #20- Cut-Out

1. CONTACT AREAS Both are broad and buccal to the faciolingual bisector (a plane bisecting the buccal & lingual halves of the crown)

2. Occlusal table:

a. outline is “square” with a slight lingual convergence (Wheeler). (Note: some textbooks describe the 3-cusp variety mandibular 2nd premolar as having a slight lingual divergence)

b. line angles, although rounded, demonstrate a definitive change in direction and will “mirror” the line angles of the abutting teeth.

3. Three distinct cusps in order of size:

a. Buccal (mesial cuspal ridge shorter than distal) cusp tip is slightly buccal to the facio- lingual bisector

b. ML: slightly wider than DL cusp c. DL: approx. 2 mm. shorter than buccal cusp d. Tips of lingual cusps near lingual outline 4. Cuspal ridges run laterally from cusp tips to join

relatively straight (almost parallel) marginal ridges 5. Triangular Ridges: none meet 6. Central Fossa:

a. Lingual, mesial and distal developmental grooves radiate forming a “Y” as they separate the 3 cusps

b. Lingual groove separates ML & DL cusps c. Mesial & distal grooves end in their

respective mesial & distal triangular fossaed. Central pit is where all 3 grooves converge

7. Triangular fossae:

a. Each has their respective marginal ridge as the base of a triangle

b. Mesial & distal grooves end at pits in their respective triangular fossa

B L

L-14

B D M

L

M M

L F L

M D

Laboratory Project: PJ-06

Tooth #10 Full Wax-Up

M

F

F L 1. Proximal Views: a. Facial outline relatively convex

compared to the central incisor b. Cervical ridge prominent on the lingual

but understated on the facial c. Triangular crown outline with the

incisal ridge centered over the root 2. Facial View:

a. This tooth is narrower mesiodistally relative to its incisal-gingival length giving it an oblong appearance

b. Developmental depressions delineate the facial lobes

c. Mesioincisal line angle is rounded but relatively square compared to DI

d. Distoincisal line angle is distinctly rounded compared to MI line angle

e. From mesial to distal, the incisal ridge slopes cervically

f. Distal contact area located slightly more cervical (middle 1/3) than the mesial contact area (junction of middle & incisal thirds)

g. Mesial and distal outlines mildly convex

3. Lingual Anatomy:

a. Prominent marginal ridges b. Triangular shaped lingual fossa that is

relatively deep & “cup-shaped” c. Convex cingulum

4. Incisal View:

a. Crown is wider M-D than it is F-L b. Labial outline is more continuously

convex than that of the central incisor c. Outline converges sharply toward the

lingual

L-15

M M D

M D

L F L

L

Lab -01

Occlusal

Fac

oratory Project/Practical: PJ-05 & PCAnatomical Features & Drawing Exercise (PJ-05)Morphological Characteristics Practical (PC-01)

Laboratory Practical: PC-07

Tooth Identification Practical

1. Anatomical Features and Drawing Exercise

Dental Anatomy Laboratory – PJ-04 Begin on August 24, 2011 Finish on September 14, 2011 Instructions and Guidelines: 1. Understanding detailed anatomical features 2. Drawing from memory 3. “Master” diagram on the left; “Cut-out” on the right 4. Vector lines 5. Use #2 pencil with an eraser 6. Restore missing anatomical features 7. Accuracy & Precision 8. Pay attention to details 9. Evaluation 2. Dental Anatomy Morphological Characteristics Practical: Administered on September 7,, 2200011 This is a practical exam ••There are 50 slides each with a question relating to an associated model or photograph. •There will be 5 multiple choice answers, choose your best answer.

3. Tooth Identification Practical Wednesday, December 7, 2011 Instructions: 1. Each question has 5 possible answers 2. Pick the BEST answer, for each question 3. Each question is displayed for only 60 seconds 4. There are 40 questions on the examination 5. All photos display the crown at the top of the screen and root oriented below it 6. Place tooth # charting diagram on paper and use it to answer questions 7. Each view is standardized on the screen as follows:

MesialDistal

ial

Lingual

L-16

Lecture Seat # ______________

Laboratory Project #PJ-07 Tooth #11- Full Wax-Up

1. Facial aspect: a. Distal cuspal ridge longer than mesial cuspal ridge b. Developmental depressions define facial lobes c. Concavity cervical to distal contact is a distinct feature of this tooth d. Mesial contour, by comparison, is straighter than the distal contour which is more rounded e. Proximal contacts:

1) Mesial: at the junction of the middle & incisal thirds 2) Distal: near the middle 1/3 of crown (more cervical than mesial)

2. Mesial aspect: a. Crown outline is triangular b. Tip of the cusp centered faciolingually or slightly facial (never lingual) c. Facial & lingual cervical ridges are well developed & crests oppose one another at the same level in the cervical 1/3 of the crown. 3. Distal aspect: Very similar to the mesial aspect except the distal marginal ridge is slightly more lingual and the distal contact (middle 1/3) area is more cervical than the mesial contact area (junction of incisal & middle thirds). 4. Lingual aspect: a. Marginal ridges are well developed b. Lingual ridge extends from the cusp tip to the cingulum dividing the lingual fossa into ML & DL fossae c. Cingulum is well developed and occupies the cervical 1/3 of the lingual surface 5. Incisal aspect: a. Incisal outline measures wider faciolingually than it does mesiodistally (opposite of maxillary incisors) b. Line angles “mirror” abutting teeth

L-17

F L

M M

M D

L

Notes:

F

L

M D

F L

Lecture Seat # _________________

Laboratory Project: PJ-088Tooth #12- Full Wax-up

M D

L F L

F

M D

L

M M

F L

1. Occlusal Anatomy a. Crown outline is “hexagonal” b. MF & DF line angles are relatively square c. Line angles “mirror” line angles of abutting teeth d. ML & DL line angles more rounded e. Central groove: crosses occlusal table mesiodistally parallel to but slightly lingual to the faciolingual bisector of the crown. f. Central groove connects M & D triangular fossae g. Crest of lingual ridge well mesial of M-D bisector h. Facial cusp: 1) is distal to M-D bisector, i.e mesial cuspal ridge is longer than the distal cuspal ridge 2) The mesial end of the mesial cuspal ridge is more lingual than the distal end of the distal cuspal ridge.i. Lingual cusp: 1) is mesial to the M-D bisector, i.e the mesial cuspal ridge is shorter than the distal cuspal ridge 2) Cuspal ridges meet at cusp tip as a continuous curve

3) Lingual cusp is 1.0 mm lower than the facial cusp 2. Triangular Ridges

a. From facial cusp & lingual cusp meet near center of occlusal table but slightly lingual to the FL bisector of the crown b. Although separated by a deep central groove, there is potential for a true transverse ridge

3. Marginal Ridges:

a. Mesial: 1) meets the mesial cuspal ridge of the facial cusp at at a near 90 degree angle

2) Mesial marginal developmental groove crosses ridge at its center 3) Crest is almost perpendicular to the faciolingual long axis bisector b. Distal: 1) Longer than mesial and uninterrupted by a groove 2) Meets the distal cuspal ridge of the facial cusp at an acute angle 4. Mesial Aspect:

a. Crown outline is trapezoidal b. Can see height of contour: 1) Facial: cervical 1/3 (cervical ridge) 2) Lingual: middle 1/3

c. Mesial marginal developmental groove is evident as it crosses thru the mesial marginal ridge d. The cervical line curves occlusally in its middle segment approx. 1.0 mm. e. Proximal Contact: located just cervical to the mesial segment of the mesial marginal ridge, facial to the mesial marginal developmental groove. f. Mesial developmental root depression: 1) Crosses the cervical line and extends to the level of the junction of the cervical & middle thirds of the crown. 2) At the level of the cervical line, the tooth surface will be convex in its facial and lingual thirds and concave in its middle third.

L-18

Lecture Seat # _________________

LABORATORY PRACTICAL: PC-03 Tooth #5- Full Crown Wax-Up

1. Occlusal Anatomy a. Crown outline is “hexagonal” b. MF & DF line angles are relatively square c. Line angles “mirror” line angles of abutting teeth d. ML & DL line angles more rounded e. Central groove: crosses occlusal table mesiodistally

parallel to but slightly lingual to the crown’s faciolingual bisector.

f. Central groove connects M & D triangular fossae g. Crest of lingual ridge well mesial of the M-D bisector h. Facial cusp:

1) is distal to M-D bisector, i.e the mesial cuspal ridge is longer than the distal cuspal ridge

2) The mesial end of the mesial cuspal ridge is more lingual than the distal end of the distal cuspal ridge.i. Lingual cusp: 1) Is mesial to the M-D bisector, i.e the mesial cuspal ridge is shorter than the distal cuspal ridge 2) Cuspal ridges meet at cusp tip as a continuous curve

2. Triangular Ridges

a. From facial cusp & lingual cusp meet near center of occlusal table but slightly lingual of a FL bisector of the crown b. Although separated by a deep central groove, there is potential for a true transverse ridge to form

3. Marginal Ridges:

a. Mesial: 1) Meets the mesial cuspal ridge of the facial cusp at at a near 90 degree angle

2) Mesial marginal developmental groove crosses ridge at its center 3) Crest is almost perpendicular to the faciolingual long-axis bisector b. Distal: 1) Longer than mesial and uninterrupted by a groove 2) Meets the distal cuspal ridge of the facial cusp at an acute angle 4. Mesial Aspect:

a. Crown outline is trapezoidal b. Can see height of contour: 1) Facial: cervical 1/3 (cervical ridge) 2) Lingual: middle 1/3 c. Mesial marginal developmental groove is evident as it crosses thru the mesial marginal ridge

F

D M

L

D D

F L

d e

L-19

F L F

M D

. The cervical line curves occlusally in its

middle segment approx.1.0 mm. . Proximal Contact: located just cervical to

the mesial segment of the mesial marginal ridge, facial to the mesial marginal developmental groove. f. Mesial developmental root depression: 1) Crosses the cervical line and extends to the level of the junction of the cervical & middle thirds of the crown. 2) At the level of the cervical line, the tooth surface will be convex in its facial and lingual thirds and concave in its middle third.

R

M D

L M L

F

M D

L

M M

F L

A. Contact Areas 1) Mesial contact is located facial to the central groove 2) Distal contact is centered 3) Both contact areas are 2-3 mm wide FL and 1 mm wide occlusogingivally B. Line Angles & Embrasures 1) MF & DF line angles are relatively “squared” 2) ML & DL line angles are “rounded” C. Cusp Placement & Size 1) Occlusal table width is comparable to the maxillary first premolar 2) Facial cusp tip is located mesial to the mesiodistal bisector of the crown 3) Lingual cusp tip is also located mesial to the mesiodistal bisector 4) Cusps are very nearly equal in height D. Marginal ridges 1) Marginal ridges are parallel relative to those of the maxillary first premolar 2) Marginal ridges approximate the same height as adjacent teeth 3) Marginal ridges are wide relative to the maxillary first premolar E. General 1) The occlusal outline of this tooth is ovoid 2) The central groove is short relative to the first premolar 3) The occlusal surface has a wrinkled appearance due to a number of supplemental grooves 4) Triangular ridges are essentially of equal length and are separated by a the central groove

Laboratory Project: PJ-099 Tooth #13- Full Crown Wax-Up etain for Dental Materials Casting

Spring Semester

L-20

Lecture Seat # ____________________

Laboratory Project: PJ-05b

Tooth #29- Full Wax-Up

1. Occlusal Anatomy a. Overall crown outline is pentagonal although the occlusal table is said to be square b. Cusps: (three-cusp variety)

1) Buccal (largest) located mesial to the mesio- distal bisector of the crown & over the buccal half of the tooth 2) ML: slightly wider than the DL cusp 3) DL: smallest of the three cusps 4) Both lingual cusps located near lingual outline

c. Triangular ridges: each cusp has one but none meet, i.e. no transverse ridges d. Cuspal ridges: run laterally from cusp tips to join straight (almost parallel) marginal ridges e. Fossae:

1) Central 2) Mesial triangular 3) Distal triangular

f. Developmental grooves: 1) Lingual }

2) Mesial } 3) Distal } 4) M & D grooves end in their respective triangular fossae

g. Contact areas: 1) are fairly wide buccolingually 2) both mesial & distal contact areas are located buccal to the faciolingual long axis bisector of the tooth

h. Line angles “mirror” line angles of abutting teeth 2. Buccal aspect:

a. Buccal cusp tip shorter than that of 1st premolar b. Contacts broad occlusogingivally c. Mesial cuspal ridge shorter than distal cuspal ridge, i.e. buccal cusp is located slightly mesial d. Height of contour (cervical ridge) located at the cervical 1/3 of the buccal surface

3. Lingual aspect: a. ML cusp: approx. 1 ½ mm. shorter than the buccal cusp & slightly wider than the DL cusp

b. DL cusp: approx. 2 mm. shorter than buccal cusp c. Lingual surface below the cuspal ridges is spherical

d. Height of contour is at the middle 1/3 of lingual surface

Radiate from within the central fossa to form a “Y”

L-21

B L B

M D

D D

B M D

L

B L

4. Mesial aspect:

a. Can see the height of contour: 1) Buccal- cervical 1/3 (cervical ridge) 2) Lingual- middle 1/3

b. Proximal contacts: cervical to the marginal ridge on the buccal ½ of the crown c. Buccal cusp tip slightly buccal to the faciolingual long axis bisector of the root

d. Marginal ridge relatively high (occlusally) and nearly horizontal 5. Distal aspect:

a. Distal marginal ridge slightly lower (more cervical) that mesial marginal ridge b. The DL cusp is superimposed on the ML cusp since the DL cusp is shorter c. Proximal contact is on the buccal ½ of the crown

6. Occlusion a. Buccal cusp occludes on the opposing mesial marginal ridge of tooth #4 b. Lingual cusp of #4 occludes with the distal marginal ridge of this tooth (#29)

Laboratory Project: PJ-10 Tooth #14-Full Crown Wax-Up

Retain for Dental Materials Casting Spring Semester

L-22

M D

L B L

B

M D

L

M M

B L

F. Embrasures/Line Angles 1) Facial line angles relatively square 2) Lingual line angles more “rounded” 3) Each line angle & embrasure “mirrors” those of its abutting tooth G. Cusp Placement & Size

1) Width of occlusal table- maxillary molar crowns are wider bucco-lingually than they are mesiodistally

2) ML cusp tip occludes in the opposing central fossa of the mandibular 1st molar

3) DL cusp tip occludes on the opposing mandibular 1st molar distal

marginal ridge 4) Facial cusps are positioned in the facial grooves of the mandibular first molar

5) Mesial cusps are wider mesio-distally than the distal cusps

6) MB, DB, ML cusps form the “primary cusp triangle”

A. Buccal Aspect: 1) Crown outline is trapezoidal 2) Buccal cusps more pointed than lingual cusps 3) Buccal groove extends facially between MB &

DB cusps B. Lingual Aspect:

1) Lingual cusps slightly longer than buccal cusps2) ML cusp very wide mesiodistally (3/5 of the

mesiodistal measurement of the crown) 3) 5th cusp (Carabelli’s) located on the lingual

aspect of the mesiolingual cusp 4) Lingual groove separates ML & DL cusps

C. Mesial Aspect:

1) Crown outline is trapezoidal 2) Cervical ridge visible on facial (cervical 1/3) 3) Greatest lingual curvature at middle 1/3 4) Contact is located buccal to the central groove

& is 2-3 mm wide buccolingually, 1 mm wide occlusocervically

D. Distal Aspect:

1) Crown outline is trapezoidal 2) Greatest buccal & lingual curvatures are the

same as stated above 3) Buccolingual dimension of the crown is slightly

smaller than that of mesial (true of all molars) 4) Contact area is centered, 2-3 mm wide bucco-

lingually & 1 mm wide occlusocervically E. Occlusal Aspect:

1) Outline is somewhat rhomboidal; ML and DF line angles are obtuse

2) Crown is wider mesially than it is distally 3) Crown is wider lingually than it is buccally 4) Four well-developed cusps. One minor 5th cusp5) Cusp sizes: ML>MB>DL>DB>5th (Wheeler) 6) Each major cusp has a triangular ridge; those of

the mesial cusps often form a transverse ridge 7) Oblique Ridge: Distal cuspal ridge of the ML

cusp meets the triangular ridge of the DB cusp 8) The low point of the oblique ridge is the same

height as the mesial and distal marginal ridges 9) The marginal ridges should be the same height

as those of each adjacent crown 10) There are two major fossae (central & distal)

and two minor fossae (mesial triangular & distal triangular).

Lecture Seat # ____________________

Laboratory Project: PJ-11 Tooth #30- Full Wax-Up

D M M D

M

B

B L

1. Occlusal Anatomy a. Cusps:

1) MB (largest), DB, ML (tallest), DL (2nd tallest), and D (smallest) 2) Distal cusp: smallest cusp and is located at or slightly lingual to the DB line angle 3) Buccal cusps are more rounded, lingual cusps more pointed

b. Triangular ridges: each cusp has one but none meet, i.e. no transverse ridges c. Cuspal ridges: flow into the marginal ridges at the perimeters d. Fossae:

1) Central 2) Mesial triangular 3) Distal triangular

e. Developmental grooves: 1) Central

2) Mesiobuccal 3) Distobuccal 4) Lingual

f. Crown converges lingually, i.e. buccal half is wider than lingual half g. Contact areas: both mesial & distal located buccal to the faciolingual bisector (a line bisecting the crown into buccal & lingual halves)

1) Mesial: 1 mm cervical to the marginal ridge

2) Distal: 1 mm cervical to the distal cuspal ridge of the distal cusp

3) Line angles “mirror” line angles of abutting teeth

2. Buccal aspect:

a. Trapezoidal with parallel sides at occlusal & cervical b. All cusps visible (lingual cusps taller) c. MB cusp widest of the buccal cusps and its cuspal ridges meet at nearly a flat angle. d. DB cusp almost as wide as MB cusp & cuspal ridges meet at a more significant angle e. Distal cusp is the smallest and although rounded, is more pointed than the other buccal cusps. f. Two buccal grooves: MB & DB (longer of two) g. Cervical ridge at the cervical third of the buccal surface of the crown (mesial 2/3 only)

3. Lingual Aspa. ML cus

b. Linguac. Height

4. Mesial aspea. Crown ob. Can see

1) Bucc2) Lingu

c. Proximamargina

5. Distal aspec

a. Crown ob. Distal cu

the DF limm belocusp.

L-23

B M D

L

D

L B

ect: p slightly taller & wider than DL cuspl developmental groove visible of curvature will be at the middle 1/3

ct: utline is rhomboidal the height of contour: al- cervical 1/3 (cervical ridge) al- middle 1/3 l contacts: 1 mm cervical to the l ridge on the buccal ½ of the crown

t: utline is rhomboidal sp position may be slightly lingual to ne angle, i.e., the distal contact is 1 w the distal cuspal ridge of the distal

D

B L B

B D M

L

D D

B L

F. Embrasures/Line Angles 1) Facial line angles relatively square 2) Lingual line angles more “rounded” 3) Each line angle & embrasure “mirrors” those of its abutting tooth G. Cusp Placement & Size

1) Width of occlusal table- maxillary molar crowns are wider bucco-lingually than they are mesiodistally

2) ML cusp tip occludes in the opposing central fossa of the mandibular 1st molar

3) DL cusp tip occludes on the opposing mandibular 1st molar distal

marginal ridge 4) Facial cusps are positioned in the facial grooves of the mandibular first molar

5) Mesial cusps are wider mesio-distally than the distal cusps

6) MB, DB, ML cusps form the “primary cusp triangle”

A. Buccal Aspect: 1) Crown outline is trapezoidal 2) Buccal cusps more pointed than lingual cusps 3) Buccal groove extends facially between MB &

DB cusps B. Lingual Aspect:

1) Lingual cusps slightly longer than buccal cusps2) ML cusp very wide mesiodistally (3/5 of the

mesiodistal measurement of the crown) 3) 5th cusp (Carabelli’s) located on the lingual

aspect of the mesiolingual cusp 4) Lingual groove separates ML & DL cusps

C. Mesial Aspect:

1) Crown outline is trapezoidal 2) Cervical ridge visible on facial (cervical 1/3) 3) Greatest lingual curvature at middle 1/3 4) Contact is located buccal to the central groove

& is 2-3 mm wide buccolingually, 1 mm wide occlusocervically

D. Distal Aspect:

1) Crown outline is trapezoidal 2) Greatest buccal & lingual curvatures are the

same as stated above 3) Buccolingual dimension of the crown is slightly

smaller than that of mesial (true of all molars) 4) Contact area is centered, 2-3 mm wide bucco-

lingually & 1 mm wide occlusocervically E. Occlusal Aspect:

1) Outline is somewhat rhomboidal 2) Crown is wider mesially than it is distally 3) Crown is wider lingually than it is bucally 4) Four well-developed cusps. One minor 5th cusp5) Cusp sizes: ML>MB>DL>DB>5th (Wheeler) 6) Each major cusp has a triangular ridge; those of

the mesial cusps often form a transverse ridge 7) Oblique Ridge: Distal cusp ridge of the ML cusp

meets the triangular ridge of the DB cusp 8) The low point of the oblique ridge is the same

height as the mesial and distal marginal ridges 9) The marginal ridges should be the same height

as those of each adjacent crown 10) There are two major fossae (central & distal)

and two minor fossae (mesial triangular & distal triangular).

L-24

M

LABORATORY PRACTICAL: PC-05

Tooth #3-Full Crown Wax-Up

Lecture Seat # ____________________

LABORATORY PRACTICAL: PC-06Tooth #19- Full Crown Wax-up

1. Occlusal Anatomy a. Cusps:

1) MB (largest), DB, ML (tallest), DL (2nd tallest), and D (smallest) 2) Distal cusp: smallest cusp and is located at or slightly lingual to the DB line angle 3) Buccal cusps are more rounded, lingual cusps more pointed

b. Triangular ridges: each cusp has one but none meet, i.e. no transverse ridges c. Cuspal ridges: flow into the marginal ridges at the perimeters d. Fossae:

1) Central 2) Mesial triangular 3) Distal triangular

e. Developmental grooves: 1) Central

2) Mesiobuccal 3) Distobuccal 4) Lingual

f. Crown converges lingually, i.e. buccal half is wider than lingual half g. Contact areas: both mesial & distal located buccal to the faciolingual bisector (a line bisecting the crown into buccal & lingual halves)

1) Mesial: 1 mm cervical to the marginal ridge

2) Distal: 1 mm cervical to the distal cuspal ridge of the distal cusp

3) Line angles “mirror” line angles of abutting teeth

2. Buccal aspect:

a. Trapezoidal with parallel sides at occlusal & cervical b. All cusps visible (lingual cusps taller) c. MB cusp widest of the buccal cusps and its cuspal ridges meet at nearly a flat angle. d. DB cusp almost as wide as MB cusp & cuspal ridges meet at a more significant angle e. Distal cusp is the smallest and although rounded, is more pointed than the other buccal cusps. f. Two buccal grooves: MB & DB (longer of two) g. Cervical ridge at the cervical third of the buccal surface of the crown (mesial 2/3 only)

3

4

5

L-25

M D D M

M D

L F L

B

D M L

B L

. Lingual Aspect:

a. ML cusp slightly taller & wider than DL cusp b. Lingual developmental groove visible c. Height of curvature will be at the middle 1/3

. Mesial aspect:

a. Crown outline is rhomboidal b. Can see the height of contour:

1) Buccal- cervical 1/3 (cervical ridge) 2) Lingual- middle 1/3

c. Proximal contacts: 1 mm cervical to the marginal ridge on the buccal ½ of the crown

. Distal aspect: a. Crown outline is rhomboidal b. Distal cusp position may be slightly lingual to

the DF line angle, i.e., the distal contact is 1 mm below the distal cuspal ridge of the distal cusp.

Lecture Seat # ____________________

Laboratory Project: PJ-1212Tooth #31- Full Crown Wax-up

B L B

D M M D

B M D

L

D

B L

M

1. Occlusal Anatomy a. Cusps:

1) Four: MB, DB, ML, & DL 2) All are of relative equal size

b. Triangular ridges: each cusp has one 1) MB & ML meet to form a transverse ridge 2) DB & DL meet to form a transverse ridge

c. Cuspal ridges: flow into the marginal ridges at the perimeters d. Fossae:

1) Central 2) Mesial triangular 3) Distal triangular

e. Developmental grooves: 1) Central: runs mesiodistally, slightly lingual to the faciolingual bisector

2) Buccal 3) Lingual NOTE: Both B & L grooves cross the central groove at right angles dividing occlusal surface into mesial and distal halves forming a “+” sign

f. Supplemental grooves: 1) Usually many 2) MB, ML, DB, DL at respective ends of the

central groove & within their triangular fossae g. Although the occlusal surface of the crown is said to be rectangular, there is a slight distal convergence

h. Crown slightly wider M-D than B-L 1) Greatest B-L meas. in mesial ½ of crown

2) Cervical ridge prominent only on MB lobe i. Line angles “mirror” the line angles of the abutting teeth

2. Buccal aspect:

a. All cusps are visible (lingual cusps are modestly taller) b. MB cusp slightly taller than DB c. Buccal groove separates the two buccal cusps d. Both buccal cusps have equal width mesiodistally e. Cervical ridge is evident on the cervical 1/3 of the buccal surface but more prominent on the mesial ½ f. Mesial & Distal walls taper from the contact areas toward the CEJ

3. Lingual aspect: a. Although there is a lingual convergence of the mesial & distal walls, it is very slight, i.e. little (if any) of the mesial or distal surface can be seen b. Both lingual cusps are modestly taller than the buccal cusps c. Lingual developmental groove separates the ML & DL cusps d. Height of curvature is at the middle 1/3

L-26

4. Mesial aspect:

a. Crown outline is rhomboidal b. Can see the height of contour:

1) Buccal- cervical 1/3 (cervical ridge) 2) Lingual- middle 1/3

c. Proximal contact: Middle 1/3 (occlusocervically) and buccal of center (central groove)

d. Buccal cusps closer to the faciolingual bisector line than are the lingual cusps.

e. Buccal cusps are modestly shorter and more rounded, lingual more pointed

5. Distal aspect:

a. Crown narrower distally than it is mesially (distal convergence)

b. Contact area (with 3rd molar) more in thecenter

6. Occlusion:

a. MB cusp: Opposing mesial marginal ridge of tooth #2

b. DB cusp: Opposing central fossa of tooth #2

DENTAL ANATOMY 6543 – Tooth #26 Cut-Out Teeth Laboratory Project Quality Assessment Form Student Name:

Last First Lab Seat # Lec Seat # Tooth #

26 Project # PJ-01 Finish Date:

/ / Grading Instructor: Grade:

Anterior Anatomical Waxing Standard Instructions: 1) Students will study all categories below and place a check mark next to each after understanding the specific criteria, 2) Instructor will indicate a status for the applicable categories (A, G, or E), 3) Instructor will signify approval of the 5 Item Category Summaries by signing and dating, and 4) Instructor will place a P (Pass) of F (Fail) grade in the upper box at end of exercise.

1 CONTACTS & HEIGHT Applicable to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Mesial Incisal Angle Height

B Distal Incisal Angle Height

C Incisal Ridge/Edge Angulation

D Incisal Ridge/Edge Thickness

E Facial Incisal Edge Contour

F Lingual Incisal Edge Contour Contacts & Height Summary

2 FACIAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Facial Crown Outline

B Mesial Facial Line Angle

C Distal Facial Line Angle

D Facial Incisal Edge Contour

E Incisal Ridge/Edge Angulation

F Width at Contact Areas Facial Surface Summary

3 LINGUAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Lingual Incisal Edge

B Mesial Marginal Ridge

C Distal Marginal Ridge

D Lingual Fossa Lingual Surface Summary

4 PROXIMAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Mesial Surface Contour

B Distal Surface Contour

C Mesial Incisal Angle

D Distal Incisal Angle Proximal Surface Summary

5 WAXING SKILLS Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Marginal Adaptation

B Smoothness of Wax

C Polish of wax-up

D Neatness of Project Waxing Skills Summary

Additional Instructor Comments:

DENTAL ANATOMY 6543 – Tooth #12 Cut-out Teeth Laboratory Project Quality Assessment Form Student Name:

Last First Lab Seat # Lecture Seat # Tooth #

12 Project # PJ-02 Finish Date:

/ / Grading Instructor: Grade:

Posterior Anatomical Waxing Standard Instructions: 1) Students will study all categories below and place a check mark next to each after understanding the specific criteria, 2) Instructor will indicate a status for the applicable categories (A, G, or E), 3) Instructor will signify approval of the 4 Item Category Summaries by signing and dating, and 4) Instructor will place a P (Pass) of F (Fail) grade in the upper box at end of exercise.

1 CONTACTS & HEIGHT Applicable to Project?

Instructor Comments, Approval & Date

Acceptable

Good

Excellent

A Mesial Proximal Contact B Mesial Marginal Ridge Contacts & Height Summary

2 MESIAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Marginal Ridge Height B Marginal Groove Placement C Proximal Contact Placement D Root Surface Depression E Cervical Line Placement F Mesial Lingual Surface Contour G Facial Lingual Surface Contour Facial Surface Summary

3 OCCLUSAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Mesial Marginal Ridge Outline B Triangular Ridge Height C Triangular Ridge Width D Central Groove Placement E Mesial Marginal Ridge Groove F Mesial Triangular Fossa G Distal Triangular Fossa H Presence of Secondary Anatomy I Depth of Developmental Pits &

Groove

Lingual Surface Summary

4 WAXING SKILLS Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Marginal Adaptation B Smoothness of Wax C Polish of wax-up D Neatness of Project Waxing Skills Summary

Additional Instructor Comments:

DENTAL ANATOMY 6543 – Posterior Cut-out Teeth Laboratory Project Quality Assessment Form Student Name:

Last First Lab Seat # Lecture Seat # Tooth #

19 Project # PJ- Finish Date:

/ / Grading Instructor: Grade:

Posterior Anatomical Waxing Standard Instructions: 1) Students will check categories applicable to this project, 2) Instructor will indicate a status for the applicable categories (A, G, or E), 3) Instructor will signify approval of the 6 Item Category Summaries by signing and dating, 4) Instructor will place a P (Pass) of F (Fail) grade in the upper box, and 4) an unacceptable proximal contact will ALWAYS result in a failing grade.

1 CONTACTS & HEIGHT Applicable to Project?

Instructor Comments, Approval & Date

Acceptable

Good

Excellent

A Mesial Proximal Contact B Distal Proximal Contact C Cusp Tip Heights & Placements D Marginal Ridge Heights E Cuspal Ridge Placements F Mesial & Distal Occlusal Embrasure Contacts & Height Summary

2 FACIAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Facial Crown Outline B Cusp Tip Placement(s) C Mesial & Distal Facial Line Angles D Mesial & Distal Facial Embrasures E Facial Cervical Ridge F Facial Ridge G Developmental Groove Placement(s) Facial Surface Summary

3 LINGUAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Lingual Crown Outline B Cusp Tip Placement(s) C Mesial & Distal Lingual Embrasures D Lingual Height of Contour E Lingual Ridge(s) Lingual Surface Summary

4 OCCLUSAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Triangular Ridge Placement(s) B Developmental Groove Placements C Presence of Secondary Anatomy D Depth of Developmental Pit(s) & Groove(s) E Occlusal Crown Outline Occlusal Surface Summary

5 PROXIMAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Mesial & Distal Contact Contours B Cervical Interproximal Forms C Mesial & Distal Cervical Embrasures D Proximal Crown Outline Proximal Surface Summary

6 WAXING SKILLS Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Marginal Adaptation B Smoothness of Wax C Polish of wax-up D Neatness of Project Waxing Skills Summary

Additional Instructor Comments:

DENTAL ANATOMY 6543 – Anterior Typodont Teeth Laboratory Project Quality Assessment Form Student Name:

Last First Lab Seat # Lecture Seat # Tooth #

Project # PJ- Finish Date: / /

Grading Instructor: Grade:

Anterior Anatomical Waxing Standard Instructions: 1) Students will check categories applicable to this project, 2) Instructor will indicate a status for the applicable categories (A, G, or E), 3) Instructor will signify approval of the 5 Item Category Summaries by signing and dating, 4) Instructor will place a P (Pass) of F (Fail) grade in the upper box, and 4) an unacceptable proximal contact will ALWAYS result in a failing grade.

1 CONTACTS & HEIGHT Applicable to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Mesial Proximal Contact B Distal Proximal Contact C Incisal Ridge/Edge Height D Incisal Ridge/Edge Anatomy E Cusp Tip Placement F Cuspal Ridges G Mesial Incisal Embrasure H Distal Incisal Embrasure Contacts & Height Summary

2 FACIAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Facial Crown Form & Anatomy B Mesial Facial Line Angle C Distal Facial Line Angle D Mesial Facial Embrasure E Distal Facial Embrasure F Facial Cervical Ridge G Developmental Depressions H Facial Ridge Facial Surface Summary

3 LINGUAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Lingual Crown Form & Anatomy B Mesial Marginal Ridge C Distal Marginal Ridge D Lingual Fossa(e) E Lingual Ridge F Cingulum G Mesial Lingual Embrasure H Distal Lingual Embrasure I Lingual Cervical Ridge Lingual Surface Summary

4 PROXIMAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Mesial Contact Contour B Distal Contact Contour C Cervical Interproximal Form D Mesial Cervical Embrasure E Distal Cervical Embrasure Proximal Surface Summary

5 WAXING SKILLS Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Marginal Adaptation B Smoothness of Wax C Polish of wax-up D Neatness of Project Waxing Skills Summary

Additional Instructor Comments:

DENTAL ANATOMY 6543 – Anterior Typodont Teeth Laboratory Practical Quality Assessment Form Student Name:

Last First Lab Seat # Lecture Seat # Tooth #

Practical # PC- Finish Date: / /

Grading Instructor: Grade:

Anterior Anatomical Waxing Standard Instructions: 1) Students will check categories applicable to this project, 2) Student will evaluate their pattern for each category, 3) Instructor will check 1 of 3 evaluation points (Unacceptable, Acceptable, or Excellent) for each item and deduct points, if indicated, 4) Instructor will add up deductions for each of the categories then subtract total from 100 and place this numerical grade in the upper box, and 5) an unacceptable proximal contact will ALWAYS result in a failing grade.

1 CONTACTS & HEIGHT Potential Point

Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Mesial Proximal Contact 2 B Distal Proximal Contact 2 C Incisal Ridge/Edge Height 2 D Incisal Ridge/Edge Anatomy 2 E Cusp Tip Placement 1 F Cuspal Ridges 1 G Mesial Incisal Embrasure 1 H Distal Incisal Embrasure 1 Contacts & Height Summary 12

2 FACIAL SURFACE Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Facial Crown Form/Anatomy 2 B Mesial Facial Line Angle 2 C Distal Facial Line Angle 2 D Mesial Facial Embrasure 2 E Distal Facial Embrasure 2 F Facial Cervical Ridge 1 G Developmental Depressions 1 H Facial Ridge 1 Facial Surface Summary 13

3 LINGUAL SURFACE Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Lingual Crown Form/Anatomy 1 B Mesial Marginal Ridge 2 C Distal Marginal Ridge 2 D Lingual Fossa(e) 1 E Lingual Ridge 1 F Cingulum 1 G Mesial Lingual Embrasure 2 H Distal Lingual Embrasure 2 I Lingual Cervical Ridge 1 Lingual Surface Summary 13

4 PROXIMAL SURFACE Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Mesial Contact Contour 1 B Distal Contact Contour 1 C Cervical Interproximal Form 2 D Mesial Cervical Embrasure 1 E Distal Cervical Embrasure 1 Proximal Surface Summary 6

5 WAXING SKILLS Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Marginal Adaptation 2 B Smoothness of Wax 2 C Polish of wax-up 1 D Neatness of Project 1 Waxing Skills Summary 6

Additional Instructor Comments:

DENTAL ANATOMY 6543 – Posterior Typodont Teeth Laboratory Project Quality Assessment Form Student Name:

Last First Lab Seat # Lecture Seat # Tooth #

Project # PJ- Finish Date: / /

Grading Instructor: Grade:

Posterior Anatomical Waxing Standard Instructions: 1) Students will check categories applicable to this project, 2) Instructor will indicate a status for the applicable categories (A, G, or E), 3) Instructor will signify approval of the 6 Item Category Summaries by signing and dating, 4) Instructor will place a P (Pass) of F (Fail) grade in the upper box, and 4) an unacceptable proximal contact will ALWAYS result in a failing grade.

1 CONTACTS & HEIGHT Applicable to Project?

Instructor Comments, Approval & Date

Acceptable

Good

Excellent

A Mesial Proximal Contact B Distal Proximal Contact C Cusp Tip Heights & Placements D Marginal Ridge Heights E Cuspal Ridge Placements F Mesial & Distal Occlusal Embrasure Contacts & Height Summary

2 FACIAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Facial Crown Outline B Cusp Tip Placement(s) C Mesial & Distal Facial Line Angles D Mesial & Distal Facial Embrasures E Facial Cervical Ridge F Facial Ridge G Developmental Groove Placement(s) Facial Surface Summary

3 LINGUAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Lingual Crown Outline B Cusp Tip Placement(s) C Mesial & Distal Facial Embrasures D Lingual Height of Contour E Lingual Ridge(s) Lingual Surface Summary

4 OCCLUSAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Triangular Ridge Placement(s) B Developmental Groove Placements C Presence of Secondary Anatomy D Depth of Developmental Pit(s) & Groove(s) E Occlusal Crown Outline Occlusal Surface Summary

5 PROXIMAL SURFACE Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Mesial & Distal Contact Contours B Cervical Interproximal Forms C Mesial & Distal Cervical Embrasures D Proximal Crown Outline Proximal Surface Summary

6 WAXING SKILLS Applicable

to Project?

Instructor Comments, Approval & Date Acceptable

Good

Excellent

A Marginal Adaptation B Smoothness of Wax C Polish of wax-up D Neatness of Project Waxing Skills Summary

Additional Instructor Comments:

DENTAL ANATOMY 6543 – Posterior Typodont Teeth Laboratory Practical Quality Assessment Form Student Name:

Last First Lab Seat # Lecture Seat # Tooth #

Practical # PC- Finish Date: / /

Grading Instructor: Grade:

Posterior Anatomical Waxing Standard Instructions: 1) Students will check categories applicable to this project, 2) Student will evaluate their pattern for each category, 3) Instructor will check 1 of 3 evaluation points (Unacceptable, Acceptable, or Excellent) for each item and deduct points, if indicated, 4) Instructor will add up deductions for each of the categories then subtract total from 100 and place this numerical grade in the upper box, and 5) an unacceptable proximal contact will ALWAYS result in a failing grade.

1 CONTACTS & HEIGHT Potential Point

Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Mesial Proximal Contact 2 B Distal Proximal Contact 2 C Cusp Tip Heights & Placements 2 D Marginal Ridge Heights 2 E Cuspal Ridge Placements 2 F Mesial & Distal Occlusal Embrasure 2 Contacts & Height Summary 12

2 FACIAL SURFACE Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Facial Crown Outline 2 B Cusp Tip Placement(s) 2 C Mesial & Distal Facial Line Angles 2 D Mesial & Distal Facial Embrasures 2 E Facial Cervical Ridge 2 F Facial Ridge 1 G Developmental Groove Placement(s) 1 Facial Surface Summary 12

3 LINGUAL SURFACE Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Lingual Crown Outline 1 B Cusp Tip Placement(s) 2 C Mesial & Distal Facial Embrasures 2 D Lingual Height of Contour 1 E Lingual Ridge(s) 1 Lingual Surface Summary 7

4 OCCLUSAL SURFACE Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Triangular Ridge Placement(s) 2 B Developmental Groove Placements 2 C Presence of Secondary Anatomy 2 D Depth of Developmental Pit(s) & Groove(s) 1 E Occlusal Crown Outline 1 Occlusal Surface Summary 8

5 PROXIMAL SURFACE Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Mesial & Distal Contact Contours 1 B Cervical Interproximal Forms 1 C Mesial & Distal Cervical Embrasures 2 D Proximal Crown Outline 1 Proximal Surface Summary 5

6 WAXING SKILLS Potential

Point Deductions

Deductions?

Unacceptable?

Acceptable?

Excellent?

Student Evaluation & Comments

A Marginal Adaptation 2 B Smoothness of Wax 2 C Polish of wax-up 1 D Neatness of Project 1 Waxing Skills Summary 6

Additional Instructor Comments: