TEETH SELECTION

TEETH SELECTION IMPORTANT FOR BDS STUDENT.....

1. Guided by: Dr. Aumkar Trivedi
Dr. Sanisth
Dr. Sweta kumar swami
Prepared by: Amrin Bhimani
Roll no. 7
Final year

2. Objectives in teeth selection
The teeth should be in harmony with the surrounding
tissues.
They should maintain the vertical dimension.
They should be efficient for mastication.
Posterior teeth should be selected based on the
function whereas the anterior teeth are selected
predominantly based on aesthetics.

3. Tooth selection
The selection of teeth for complete dentures is classified
into:
I- anterior teeth selection.
II- posterior teeth selection.

4. The anterior teeth are primary selected to satisfy
esthetic requirements, whereas the posterior teeth
are primarily selected to satisfy masticatory
functional requirements . both the anterior and
posterior teeth must function in harmony with,
and be anatomically and physiologically
compatible with the surrounding oral environment
.

5. I-anterior teeth selection
1-maxillary anterior teeth:
there are three basic considerations when selecting the
maxillary anterior teeth.
i)Size of the teeth.
ii)Form of the teeth.
iii)Shade of the teeth.

6. A.size of anterior teeth
The teeth size should be appropriate to the size of
the face and gender of the patient.
Following methods are used as guide:
I.Methods using pre-extraction records
II.Methods using anthropological measurements of
the patient.
III.Methods using theoretical concepts.
IV.Other factors.

7. Methods using pre-extraction
records.
Diagnostic casts.
they are prepared before the extraction of the teeth.
The actual size and shape can be determined but
shade of the teeth can not be determined.
Pre-extraction photograph
photographs showing the anterior,lateral and
anteriolateral views of the patient shoud be taken
before extraction. This method is useful to determine
the exact width and outline of the teeth.

8. Pre-extraction radiograph
the occluso-gingival height and the outline of the
teeth can be recorded but the contour and size can
not be accurately determined.
Teeth of close relatives
In this method size and contour of the patient’s son
or daughter’s tooth is taken as reference.
Preserved extracted teeth
This is best method to determine the size of
anterior teeth.

9. Methods using anthropological
measurement of the patient.
Anthropometric cephalic index
width of upper CI= circumference of the head
13
total width of upper anterior= bizygometic width
3.36
total width of the lower anterior= 4
th
width of the upper anterior
5
Berry’s biometric index
width of maxillary CI= bizygometic width
16
width of maxillary CI= length of the face
20

10. H. pound’s formula
width of maxillary CI= bizygometic width
16
length of maxillary CI= bizygometic width
16
Based on the width of the nose
width of the nose is measured with vernier
calliper.
The width of the nose is equal to combined width of the
anterior teeth.

12. Methods using anatomical
landmarks
Size of the maxillary arch
the distance between the incisive papilla and hamular notch on
one side is added with the distance between two hamular
notch. This gives the combined width of ant. Post. teeth of
maxillary arch.
Location of canine eminence
the distance between two canine eminence is measured along
the residual ridge, this gives the width of anterior teeth.
Location of buccal frenal attachment.
the distance between the two marking buccal frnum recorded
gives the combined width of the maxillary anteriors.
Location of corner of mouth
Location of ala of the nose.

14. Methods using theoretical
concepts
Winkler’s concept
acc. To wrinkler teeth should be selected based on three
different views,
1. physiological-biological
facial musculature contributes to the aesthetics of the
patients.
2. Psychological
the champer’s line is the psychological plane of orientation.
It is raised in happy people and tilted downward in depressed
people.
3. Biomechanical
it is not necessary to set the teeth inside or outside of the
ridge but it should be set in neutral zone.

15. Typical form theory: leon willims
this is useful to determine the size and forms of the
teeth. Acc. To him shape of the teeth should be
inverse of the face of the teeth.

17. B. form of the teeth
three factors are used as guides in the selection of
the form of the anterior teeth:
1-the form and contour of the face:
the general outline form of the tooth should
conform to the general outline of the face when
viewed from the frontal aspect. Also a tooth
viewed from the mesial and distal aspect should
conform to the contour of the facial profile.

18. 1-FACIAL FORM
it can be grouped into
square,
tapering,
ovoid
combination
This can be determined by, imagining two lines on either side of the
face running about 2.5 cm in front of the tragus of the ear and
touching the angle of the mandible,
1-if these lines are parallel of the face is square.
2-if they converge towards the chin the face is tapered
3-if they diverge away from the chin, the face is ovoid.
b-the facial profile:
(to determine the facial profile observe the relative straightness of
curvature of the profile). The labial surface of the teeth should be in
harmony with the facial profile. If the face presents a curved profile
than a tooth should be selected to harmonize with that profile.

20. 2-sex
curved facial features are always associated with
femininity, while square features are always
associated with muscularity. There for , the teeth of
females are more ovoid or tapered rather than
square , those for males are usually square.

22. 3- shape of the dental arch
The form of central incisors should not only harmonize
with the form of the face but also with the form of the
dental arch. Patients with predominantly square
dental arches often have square teeth. The same
principle of the harmony apply to the square tapering
and ovoid types, i.e. V-shaped arch is associated with
incisors that are narrower at the neck than at the
incisal edge.

24. C-color or shade of anterior teeth
1- the color of the teeth, like the form must be in
harmony with the surrounding environment if
they are to appear natural. Harmony should exist
between the color of the teeth and the color of the
skin, hair and eyes.
2-the patient's age:
The color of natural teeth change with age they get
progressively darker as a result of deposition of
secondary dentine. The general rule is that darker
teeth are more suitable for old patients while,
lighter teeth are suitable for young patients.

26. Most of natural teeth have the following
characteristics:
a- the neck of the tooth have a more pronounced
yellow color than incisal third.
b-the incisal edge is more translucent than the
body of the tooth because it is composed
entirely of enamel.
c-the upper central incisors are the lightest teeth
in the mouth. The upper lateral ,lower centrals
and laterals are slightly darken. The upper and
lower canines are more dark.
d-teeth darken slightly with age.

27. 2-mandibular anterior teeth
Selection of the lower six anterior teeth is relatively a
simple procedure. Each set of the upper anterior
teeth has a corresponding set of lower anterior teeth
which match in the size, form, and color.

28. II-posterior teeth selection
The selection of posterior teeth involves
Shade
size
Number
form

29. A-shade of posterior teeth:
the shade of posterior teeth should harmonize with the
shade of anterior teeth.

30. B-size and number of posterior
teeth:
the posterior teeth must support the cheeks and
tongue and function in harmony with
musculature in swallowing, speaking and
mastication.
the buccolingual dimension:the buccolingual dimension:
Of the artificial teeth should be less than that of
natural teeth to reduce the size of the occlusal
table, and stresses transmitted to the underlying
supporting structures. This will also permit forces
from the cheeks and tongue maintain the
dentures in their position or the residual ridge.
However, this reduction should not be
accomplished at the expense of losing support for
the cheek.

31. the anteroposterior dimension:the anteroposterior dimension:
Of posterior teeth is determined by the edentulous
between the distal surface of the canine and the
ascending are of the mandible which is usually
situated slightly anterior to the retro molar pad.
Placing teeth on the ascending area of the mandible
will direct the masticatory forces at an inclined plane.
Forces directed at an inclined plane are more
dislodging than forces directed at right angles to the
supporting structure.
the vertical length:the vertical length:
Of posterior teeth depends on, the available interarch
distance and the length of anterior teeth. The length
of maxillary first premolars should be comparable to
that of the maxillary canines to have proper esthetic
effect.

33. c- form of posterior teeth:
the form of occlusal surface of posterior teeth may be
classified according to their cuspal inclination into:
I-anatomic form
II-non anatomic form.

34. I-Anatomic form
These resembles normal newly erupted teeth. The provides the best
aesthetics and they are most commonly used type.
The anatomic form has cusps, grooves and inclined planes . the cusp
angle ranges from 20-45 with average 33.
Anatomic teeth with 30 cuspal angulation are known as pilkington-
turner teeth.

36. Il- Semi-anatomical
They are also known as modified-cusp or low cusp
teeth.
They may have 20-10 cuspal angulation. 10 semi-
angulation teeth are commonly known as functional
or anatoline teeth
They are more flexible to arrange than the anatomic
teeth.

38. III-The non anatomic form:
(cuspless or flat teeth):
Has flat occlusal surface with shallow grooves and no
cusps.
Selection of a suitable form of posterior teeth depends on
individual requirements.
The anatomic forms of posterior teeth are commonly used
for patients having normal ridge relations and well
developed ridges.
Non anatomic form; however, may be used in the
following condition:
1. cross-bite ridge relation. In this condition, the lower
posterior teeth are in a buccal relation to the upper
posteriors which is the reverse of that in normal ridge
relation.
2.cases suffering from T.M.J. disturbances.
3.in nervous or hysterical patients, or in patients where
neuro-muscular co-ordination has been lost.
4.in cases with advanced ridge resorption.