mazen doumani dental anatomy

Dr Mazen D Doumani

Master in dental sciences

Reference:

Dental anatomy: The study of the development, morphology, function, and identity of each tooth in the

human dentition. As well as: The way in wich the teeth relate to other teeth in the same dental arch and to teeth in the opposite arch.

All phases of dentistry

Dental anatomy

occlusion physiology

Esthetic

Psychological

periodontal

Dental anatomy

Occlusion

Esthetics

Phonetics

Formation of the dentition Humans have two sets of teeth in their lifetime.

First set : primary or deciduous dentition, begins

at 14th weeks in utero and is completed at about 3 years postnatally .the first teeth begin to appear in mouth at 6th month and the last one at 28th _+4month.

Second set : permanent dentition completed at 14-15

year for second permanent molar(but transition or mixed dentition from 6th -12th year because the human has decideouos and permanent teeth).

Why mixed period of dentition is a difficult time for young child ? Missing teeth

Teeth of different colors

Crowding , malposed teeth .

exfoliation

shedding

=

Maxillary teeth Mandibular teeth

Maxilla is stationary

Mandible is movable

Midline

Quadrants Upper right

Lower right

Upper left

Lower left

Anterior and Posterior teeth

anterior posterior

Occlusion The manner in wich the mandibular teeth contact the maxillary teeth

permanent

Deciduous

Function of teeth

Incisores : cutting

Canine : tearing

Premolar : tearing and grinding

Molar : grinding

Formula for human teeth Deciduous : I2\2 C1\1 M2\2 = 10

I 2\2 means incisors 2 upper , 2 lower

C2\2 means canines 1 upper ,1 lower

M2\2 means molars 2 upper , 2 lower

The total =10 in two quadrant

10 * 2 =20 tooth(milk or baby tooth)in

full mouth

Permanent :I 2\2 C 1\1 P 2\2 M 3\3

Total = 16 in two quadrant

16*2=32 in full mouth

Universal system Deciduous Permanent

Zsigmondy /palmer notation

FDI numbering system

Enamel

Cementum

Dentin

Hard Tissues

Pulpal tissue:

chamber

Root canal

Soft Tissue

PULP

Blood and Nerve supply

Cutting surfaces: - Incisal ridge or edge - Cusps

Alveolar process

Surfaces & ridges Incisor, canine : the crown of each one has 4 surfaces and a ridge

Molar ,premolar : the crown of each one has five surfaces

Facial surfaces

Buccal surface Labial surface

Lingual surface

Lingual or

palatal

Palate

The importance of the contour

Occlusal surface

INCISAL SURFACES

Mesial and distal surfaces

Mesial

distal

Cusp Is an elevation or mound on crown portion of a tooth;

making up a divisional part of the occlusal surface.

Tubercle Is a smaller elevation on some portion of the crown

produced by an extra formation of enamel

Cingulum Latin word for”girdle”

It is the lingual lobe of an anterior tooth . It makes the cervical third of the lingual surface .

Ridge Any linear elevation on the surface of of the tooth and

is named according to its location Examples: - incisal ridge - marginal ridge - buccal ridge

Marginal ridges Are rounded borders of enamel that form the mesial

and distal margins of the occlusal surfaces of molars and premolars

and the mesial and distal margins of the incisors and canine

Triangular ridges Desend from the tip of the cusp of molar and premolar

toward the central part of the occlusal surface .

How do they name? according to the cusp they belong to.

Example:buccal cusp ridge.

Comparison between transverse and oblique ridges

Fossa An irregular depression or concavity

Ligual fossae: are on lingual surface of incisors

Triangular fossa Located adjacent to the marginal ridges on the

occlusal surfaces of posterior teeth. Two types of triangular fossae are mesial and distal

Central fossae Are on the occlusal surfaces of molars ,they formed by

the convergence of ridges terminating at a central point in the bottom of the depression where there is a junction of grooves

sulcus is a long depression or valley in the surface of a tooth

between ridges and cusps, the inclines of which meet at an angle. A sulcus has a developmental groove at the junction of its inclines

developmental groove a shallow groove or line between the primary parts of

the crown or root

Buccal and lingual grooves

supplemental groove A less destinct, shallow linear depression on the

surface of a tooth, but it is supplemental to adevelopmental groove, and does not mark the junction of primary parts

MLCR, mesiolingual cusp ridge; LDG, lingual developmental groove; DLCR, distolingual cusp ridge; DTF, distal triangular fossa (outlined area); DCR, distal cusp ridge; DBDG, distobuccal developmental groove; DBCR, distobuccal cusp ridge; MTF, mesial triangular fossa (outlined area); SG, a supplemental groove.

Pits Small pinoint depressions located at the junctions of

developmental groove or terminals of those grooves.

Lobe One of the primary sections of formation in the

development of the crown .

Cusps and mamelons are representative of lobes .

Mamelon:one of three tubercles on the cutting edge of a newly erupted incisor tooth.

Roots

Division into thirds

Line angle Is formed by the junction of two surfaces and derives

its name from the combination of the two surfaces that join

Point angles Is formed by the junction of three surfaces and derives

its name from the combination of the three surfaces that join

Measurement of tooth dimensions

Clinical and anatomical crown

Malformations Include disturbances in:

1- form .

2- color.

3- arrangement.

4- structure(enamel hypoplasia).

Summary of schematic outlines Triangles:

six anterior teeth , maxillary and mandibular

A-mesial aspect

B-distal aspect

Summary of schematic outlines

trapezoids:

I. Trapezoids with longest uneven side toward occlusal or incisal surface:

A. All anterior teeth , maxillary and mandibular 1-labial aspect 2-lingual aspect

B. All posterior teeth 1- buccal aspect 2- lingual aspect

Summary of schematic outlines

trapezoids:

II. Trapezoids with shortest uneven side toward occlusal or incisal surface:

A. All maxillary posterior teeth

1-mesial aspect

2- distal aspect

Summary of schematic outlines

rhomboids:

All mandibular posterior teeth

1-mesial aspect

2- distal aspect

Interproximal form Proximal contacts of approximating teeth in the arch

protect the soft tissue(gingiva) between the teeth and referred to as interproximal space

Interdental papilla

Interproximal form Normally the gingiva covers part of cervical third of

the crown and fills the interproximal spaces.

The gingival line follows the curvature but not necessarily the level of the cervical line .

Interproximal form The cervical line is a stable anatomical demarcation.

The level of gingival line is variable.

Absence of bone over the root of the tooth is called dehisence(clift) or fenestration(window).

Interproximal form Cervicoenamel ridge

It is also called cervical ridge.

It is curvature on the crown at the cervical third above the cervical lin.

This ridge shouldn’t be overcontoured or undercontoured in full-crown restorations.

Root form Root form(shape and length) is associated with:

- overall form

- work Of the tooth

Root form Mesial view of the anterior tooth will show that the incisal

ridge or cusp is centered over the root

The measurment from cusp tip to cusp tip buccolingually is much less than the buccolingual diameter of the root base

Contact area A part of mesial or distal surface wich contacts the

neighbouring tooth.

point

line

area

diastema is a space that exists between two adjacent teeth in the

same arch that is not the result of a missing tooth.

It is most commonly seen between the maxillary right and left central incisors, but can occur between any teeth

Embrasures(spillways) when two teeth in the same arch in contact ,their

curvature adjacent to the contact area form spillway space called embrasures.

Significance of Embrasure form Serves as a spillway for food material during

mastication

Prevents food from being forced through the contact area and injuring the periodontal tissues.

Also, Enhances the self-cleansing process of the tooth by exposing the surfaces to oral fluids, mechanical cleansing, and friction from the tongue, lips, and cheeks

Overlap of the teeth

Curvatures of the Occlusal Plane

Curve of Spee Curve of Wilson