selection of teeth/ orthodontics training courses

SELECTION OF TEETHSELECTION OF TEETHINDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

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INTRODUCTIONINTRODUCTION

The selection of teeth for complete The selection of teeth for complete dentures is best understood if the anterior dentures is best understood if the anterior teeth are considered seperately from teeth are considered seperately from posterior teeth.posterior teeth.

The teeth are selected so as to rehabilitate The teeth are selected so as to rehabilitate the occlusion.the occlusion.


• Teeth should fulfill the following needs :

a. Function well

b. Allow the patient to speak normally

c. Esthetically pleasing

d. Does not abuse the tissues over residual ridges



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•Anterior teeth are primarily selected to satisfy esthetic harmony, whereas the posterior teeth are primarily selected to satisfy masticatory requirements.

•Size, shape, form, colour and arrangement of teeth should be associated with size, shape, and form of the face.

•Physical features, age and sex of individuals should also be considered


MOLD AND SHADE MOLD AND SHADE IDENTIFICATIONIDENTIFICATION

(anterior teeth)(anterior teeth)• Mold guides, mold selectors and shade

guides assist proper selection of complete dentures

• Dentsply international inc. has TRUBYTE Dentsply international inc. has TRUBYTE bioform mold numbering systems which bioform mold numbering systems which uses two no’s and one letter on lower left uses two no’s and one letter on lower left of tooth mounting card of tooth mounting card


•Lincoln dental supply company suggested a system, LOGIC CODING SYSTEM in which the universal coded no’s would be provided for shade and mold of artificial teeth.

•Meyerson tooth corporation identifies mold with number and letters.


Posterior teethPosterior teeth

Posterior teeth are often identified by Posterior teeth are often identified by name of the particular tooth form.name of the particular tooth form.

Specific molds and shades are identified Specific molds and shades are identified by no’s that represent combined mesio-by no’s that represent combined mesio-distal width of 4 posterior teeth and letters distal width of 4 posterior teeth and letters to indicate occlusogingival height of tooth.to indicate occlusogingival height of tooth.


SELECTION OF ANTERIOR SELECTION OF ANTERIOR TEETHTEETH

It is the area of the prosthetic care in It is the area of the prosthetic care in which patient should be given a primary which patient should be given a primary responsibility to determine esthetic responsibility to determine esthetic outcome like..outcome like..

Find out what the patient’s teeth were likeSelect the colour of teeth firstSelect size of teeth secondSelect mold of teeth third


Guides for selecting size of anterior Guides for selecting size of anterior teethteeth

Size of the face Size of the face Size of the maxillary archSize of the maxillary arch Incisal papilla and canine eminences or Incisal papilla and canine eminences or

buccal frenumbuccal frenumMaxillomandibular relationsMaxillomandibular relationsContour of the residual ridgesContour of the residual ridgesVertical distance between ridges Vertical distance between ridges Lips Lips


Size of the faceSize of the faceThe average width of maxillary central The average width of maxillary central

incisor is estimated to be 1/16incisor is estimated to be 1/16 thth of width of of width of face between zygomaface between zygoma

The maxillary lateral incisors vary more in The maxillary lateral incisors vary more in size, form and colour thus allowing size, form and colour thus allowing freedom in selecting teeth from standard freedom in selecting teeth from standard molds molds

TRUBYTE tooth indicator determines size TRUBYTE tooth indicator determines size of maxillary central incisorsof maxillary central incisors


Size of maxil lary archSize of maxil lary archMold selector is used to make Mold selector is used to make

measurements of maxillary castsmeasurements of maxillary castsMeasurements are made from crest of Measurements are made from crest of

incisal papilla to hamular notches & from incisal papilla to hamular notches & from one hamular notch to oppositeone hamular notch to opposite

The combined length of three legs of The combined length of three legs of triangle in mm is used on selectortriangle in mm is used on selector

Excessive loss of bone influence size Excessive loss of bone influence size mostly lengthmostly length


Incisive papil la and canine Incisive papil la and canine eminenceeminence

If Canine eminences are discernible, a line If Canine eminences are discernible, a line can be placed on the cast distal can be placed on the cast distal termination of eminencetermination of eminence

If not discernible, attachment of buccal If not discernible, attachment of buccal frenum can be used.frenum can be used.

Another method to locate distal of canine Another method to locate distal of canine eminence is to use occlusal rim. Patient is eminence is to use occlusal rim. Patient is asked to relax with lip touching after asked to relax with lip touching after placing rim placing rim


A pointed instument passed on the line A pointed instument passed on the line parallel to pupils of eye & diatance is parallel to pupils of eye & diatance is measured between the marks following measured between the marks following the contour of arch measured in mm.the contour of arch measured in mm.


Maxil lomandibular relationsMaxil lomandibular relations

Any disproportion in size of mandibular & Any disproportion in size of mandibular & maxillary arches influence length, width & maxillary arches influence length, width & position of teeth position of teeth

In protruded mandibles, face is longer thus In protruded mandibles, face is longer thus requires longer teethrequires longer teeth

In retruded mandible the mandibular In retruded mandible the mandibular anterior teeth are smalleranterior teeth are smaller


Contour of residual r idgesContour of residual r idgesArtificial teeth should be placed to follow Artificial teeth should be placed to follow

the contour of residual ridges that existed the contour of residual ridges that existed when natural teeth where presentwhen natural teeth where present

Resorption of the maxillaResorption of the maxillaAnteriorAnterior - vertical & palatal direction- vertical & palatal directionposteriorposterior - vertical & medial direction - vertical & medial direction

Resorption of the mandibleResorption of the mandibleAnteriorAnterior - vertical & lingual direction- vertical & lingual directionposteriorposterior - vertical & slightly lingual- vertical & slightly lingual


Vertical distance between the Vertical distance between the ridgesridges

The length of teeth is determined by The length of teeth is determined by available space between existing ridgesavailable space between existing ridges

Denture bases that simulate oral mucosa Denture bases that simulate oral mucosa are referred to as characterized, are referred to as characterized, personalised or natural appearingpersonalised or natural appearing


The l ipsThe l ips

When lips are relaxed & apart, labial When lips are relaxed & apart, labial surfaces of maxillary anterior teeth support surfaces of maxillary anterior teeth support the upper lipthe upper lip

When teeth are in occlusion & lips are When teeth are in occlusion & lips are together, the labial, incisal third of together, the labial, incisal third of maxillary anterior teeth supports the maxillary anterior teeth supports the superior border of lower lipsuperior border of lower lip


In speech, the incisal edges of maxillary In speech, the incisal edges of maxillary anterior teeth contact the lower lip at the anterior teeth contact the lower lip at the junction of moist & dry surface of junction of moist & dry surface of vermillion border & can be best vermillion border & can be best demonstrated when letter “F” as in “fifty demonstrated when letter “F” as in “fifty five” is pronouncedfive” is pronounced

The properly contoured maxillary occlusal The properly contoured maxillary occlusal rims will include this position as incisal rims will include this position as incisal edge position & will aid in determining edge position & will aid in determining length of teethlength of teeth


FORM OF ANTERIOR TEETHFORM OF ANTERIOR TEETH

FORM AND CONTOUR OF FACEFORM AND CONTOUR OF FACE

SEXSEX

AGEAGE


Form and contour of faceForm and contour of face

The form of tooth should conform to the The form of tooth should conform to the contour of face as considered from labial, contour of face as considered from labial, mesial, distal & incisal aspectsmesial, distal & incisal aspects

Tooth viewed from frontal aspect should Tooth viewed from frontal aspect should conform general outline of face whereas conform general outline of face whereas viewed from mesial or distal should viewed from mesial or distal should conform to the contour of profile conform to the contour of profile


Indicator may be used to establish facial Indicator may be used to establish facial outline as follows ;outline as follows ;a)a) Place the tooth indicator on the Place the tooth indicator on the patient’s face allowing the nose to come patient’s face allowing the nose to come through the center of trianglethrough the center of triangleb)b) Centre pupils of eye & all the indicator Centre pupils of eye & all the indicator with center line coinciding medial line of with center line coinciding medial line of faceface

In square form the sides of face will In square form the sides of face will follow vertical lines of indicatorfollow vertical lines of indicator

In tapering face, sides of face from In tapering face, sides of face from forehead to the angle of jaw will taper at forehead to the angle of jaw will taper at an inward diagonal.an inward diagonal.www.indiandentalacademy.comwww.indiandentalacademy.com

To determine facial profile, observe To determine facial profile, observe relative straightness or curvature of profile relative straightness or curvature of profile by checking forehead, base of nose & by checking forehead, base of nose & point of chin.point of chin.

If these points are in a line, profile is If these points are in a line, profile is straight.straight.

If these points are recessive profile is If these points are recessive profile is curved curved


SEXSEX

Curved facial features are associated with Curved facial features are associated with feminity & square with masculinityfeminity & square with masculinity

Form of teeth vary as features varyForm of teeth vary as features vary


AGEAGE

Lips lose their curves and cupids bow and Lips lose their curves and cupids bow and teeth wear at the incisal edges & teeth wear at the incisal edges & interproximal surfaces.interproximal surfaces.


Colour or shade of anterior Colour or shade of anterior teethteeth

Colour is the sensation resulting from Colour is the sensation resulting from stimulation of retina of eye by light wawes stimulation of retina of eye by light wawes of certain lengthof certain length

Shade is degree of darkness of a colour Shade is degree of darkness of a colour with reference to its mixture with blackwith reference to its mixture with black

Two principal colours yellow & grey are Two principal colours yellow & grey are evident.evident.

Yellow is evident in gingival third & grey in Yellow is evident in gingival third & grey in incisal thirdincisal third


The position of patient & source of light The position of patient & source of light are important factors in colour selectionare important factors in colour selection

Teeth should be observed from different Teeth should be observed from different angles to make certain that shadows do angles to make certain that shadows do not influence colournot influence colour

Patients mouth should not be opened too Patients mouth should not be opened too widewide

White light is suitableWhite light is suitable


If proper shade is hard to establish the If proper shade is hard to establish the tooth & shade guide shoud be viewed tooth & shade guide shoud be viewed from a distance of 6 to 8 feetfrom a distance of 6 to 8 feet

Harmony should be there between colour Harmony should be there between colour of teeth & colour of skin, hair & eyesof teeth & colour of skin, hair & eyes

If teeth are allowed to remain in guide If teeth are allowed to remain in guide holder held to one side of nose of patient holder held to one side of nose of patient the that is in harmony wii be recognisedthe that is in harmony wii be recognised


Posterior teeth selectionPosterior teeth selection

Selection of posterior teeth is made in Selection of posterior teeth is made in such a way so that it fulfills the followng such a way so that it fulfills the followng requirements:requirements:

1. Permits the tongue & cheeks to function 1. Permits the tongue & cheeks to function effectively during speech and msticationeffectively during speech and mstication

2. More acceptable esthetically2. More acceptable esthetically 3. Make it easy for patients to get adapted 3. Make it easy for patients to get adapted

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4. Fulfills requirement neutral zone, which is 4. Fulfills requirement neutral zone, which is a space resulting from the removal of a space resulting from the removal of posterior teeth & loss of bone from posterior teeth & loss of bone from residual ridgesresidual ridges


Shade Shade

The shade of posterior teeth should The shade of posterior teeth should harmonize with the shade of anterior teethharmonize with the shade of anterior teeth

It is advisable to select slightly lighter It is advisable to select slightly lighter shade for the premolars if they are shade for the premolars if they are arranged estheticallyarranged esthetically


Size and numberSize and numberThe size & number of posterior teete are The size & number of posterior teete are

closely related to usageclosely related to usageThe buccogingival dimension of artificial The buccogingival dimension of artificial

teeth should be less than that of natural teeth should be less than that of natural teeth to reduce size of food tableteeth to reduce size of food table

The anterioposterior dimensions of The anterioposterior dimensions of posteriors are determined by edentulous posteriors are determined by edentulous area between distal of mandibular cuspids area between distal of mandibular cuspids & ascending area of mandible& ascending area of mandible


Form Form

The proximal, lingual & buccal surfaces The proximal, lingual & buccal surfaces should be contoured like natural teethshould be contoured like natural teeth

When eccentric jaw movements When eccentric jaw movements occurs,either cusp or monoplane teeth occurs,either cusp or monoplane teeth can be used can be used


Materials for artif icial teethMaterials for artif icial teeth Porcelain teethPorcelain teethPorcelain teeh has greater wear Porcelain teeh has greater wear

resistanceresistancePorcelain teeth has better retention of Porcelain teeth has better retention of

surface polish & finishsurface polish & finishPorcelain teeth do not bond to denture Porcelain teeth do not bond to denture

base resinbase resinPorcelain teeth may produce click in Porcelain teeth may produce click in

function & can accumulate stain around function & can accumulate stain around gingival margingingival margin


Resin teethResin teethResin teeth has natural appearanceResin teeth has natural appearanceResin teeth has the capablity to bond to Resin teeth has the capablity to bond to

most heat cured denture base resinsmost heat cured denture base resinsResin teeh has less wear resistance,which Resin teeh has less wear resistance,which

can result in reduced vertical dimension of can result in reduced vertical dimension of occlusionocclusion


Metal- inert teethMetal-inert teethMetal-insert teeth has improved occlusal Metal-insert teeth has improved occlusal

wear resistancewear resistanceMetal-insert teeth are not noisy as Metal-insert teeth are not noisy as

porcelain teethporcelain teethMetal-inserted teeth are costly, and they Metal-inserted teeth are costly, and they

may not be as esthetic as other artificial may not be as esthetic as other artificial teethteeth


TYPES OF TEETHTYPES OF TEETH

Anatomic teethAnatomic teethAnatomic teeth are artificial teeth that Anatomic teeth are artificial teeth that

closely resemble the anatomic form of closely resemble the anatomic form of natural unabraded teethnatural unabraded teeth


Non-anatomic teethNon-anatomic teethArtificial teeth in which the occlusal Artificial teeth in which the occlusal

surfaces are not copies from natural form, surfaces are not copies from natural form, but are given forrms that,seem more but are given forrms that,seem more nearly to fulfill the requirements of nearly to fulfill the requirements of mastication,tissue tolerance etcmastication,tissue tolerance etc


Cusp less teethCusp less teethCuspless teeth are those which are Cuspless teeth are those which are

designed without cuspal prominances of designed without cuspal prominances of masticatory surfacesmasticatory surfaces


Zero-degree teethZero-degree teethZero-degree teeth are prosthetic teeth Zero-degree teeth are prosthetic teeth

having no cusp angles in relation to the having no cusp angles in relation to the horizontal planehorizontal plane


CONCLUSIONCONCLUSION

The selection of teeth and their The selection of teeth and their arrangement to meet esthetic arrangement to meet esthetic requirements demand artistic skill in requirements demand artistic skill in addition to scientific knowledge.addition to scientific knowledge.

There are no rules of thumb for this There are no rules of thumb for this procedure; however, there are anatomic procedure; however, there are anatomic landmarks and manufactured aids that landmarks and manufactured aids that can be used as guides.can be used as guides.


BIBLIOGRAPHYBIBLIOGRAPHY

Essentials of complete denture Essentials of complete denture prosthodontics – prosthodontics – Sheldon winklerSheldon winkler

Textbook of complete dentures – Textbook of complete dentures – charles M. Heartwellcharles M. Heartwell

Prosthodontic treatment for edentulous Prosthodontic treatment for edentulous patients – patients – BoucherBoucher

Dental laboratory procedures (complete Dental laboratory procedures (complete dentures) – dentures) – Robert M.MorrowRobert M.Morrow



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