Cuspal Arrangement of Teeth and Occlusal Morphology

Question 1

5 determinants of tooth position

Answer 1

lips and cheeks
tongue
proximal contacts
occlusal contacts
oral habits

Question 2

Forces of mastication 
normal?
maximum where? 
dentures?
\+ implications on gender

Answer 2

Male is greater than female

Molar - more force than incisor teeth

normal chewing is about 25% of maximum force

Dentures – only get 25% of force of natural dentition

• varies with age and diet
• as you get older chewing is not as efficient

Question 3

definition of occlusal stability

Answer 3

equalization of contacts that prevents tooth movement after closure

stable = open and close in a repeatable pattern

Question 4

inter-arch relationship of teeth

Answer 4

where the occluding surfaces of the teeth are intercuspated to resist the vertical and horizontal physiologic forces

part of maintaining stability

Question 5

interarch relationships for dental stability - forces

Answer 5

relationship of the interarch articulation allows the forces to be transmitted to attachment apparatus ALONG THE LONG AXIS OF THE TOOTH

Question 6

interarch relationships for dental stability - space

Answer 6

Opposing teeth should meet solidly from a vertical dimension of occlusion (VDO) vertical dimension of rest (VDR) to a point that is acceptable to allow for ADEQUATE INTEROCCLUSAL REST SPACE (freeway space = VDR-VDO)

Question 7

free way space

Answer 7

VDR - VDO

space at rest usually about 3 mm and can be produced after patient says the word ‘Emma’

Question 8

interarch relationships for dental stability - contacts

Answer 8

contacts during a working side movement of the mandible should DISARTICULATE THE TEETH ON THE NON-WORKING SIDE

Question 9

interarch relationships for dental stability - excursions

Answer 9

anterior and lateral excursions should be compatible with the posterior cuspal anatomy to AVOID posterior interferences

Question 10

condylar guidance

Answer 10

angle at which the condyles descend along the articular eminence

Question 11

protrusive records are made in order to adjust?

Answer 11

angle at which the condyles descend along the articular eminence (condylar guidance)

Question 12

shape of the articular disc

Answer 12

biconcave

Question 13

function of plane of occlusion

Answer 13

arranged to permit maximum use of tooth contacts during function

Question 14

occlusal plane in sagittal plane

Answer 14

curve of spee

Question 15

occlusal plane in frontal plan

Answer 15

curve of wilson

Question 16

curve of spee
definition
view
importance

Answer 16

posterior to anterior along the buccal cusp of the canine to the last molar
viewed in sagittal plane

helps maintain anatomy of teeth and function

Question 17

curve of wilson
definition
view
importance

Answer 17

from buccal cusp to lingual cusp through the lingual and buccal acorss the arch

viewed from frontal

Question 18

classification of cusps

Answer 18

Supporting = centric cusps or functional

Guiding = non-centric, guiding, shearing

Question 19

supporting cusps

functions and characteristics

Answer 19

function/centric cusps
LINGUAL/palatal of upper
mandibular buccal cusps

1. maintain VDO
2. play major role in mastication
3. rounded shape

Question 20

guiding cusps

functions and characteristics

Answer 20

non-centric, guiding, shearing
maxillary buccal and mandibularl lingual

1. assist in shearing food
2. sharp tips
3. minimize tissue impingement and to maintain the bolus of food on the occlusal table during mastication

Question 21

posterior cuspal relationship

Answer 21

the mandibular buccal cusps occlude in the central fossae of the maxillary teeth

the maxillary lingual cusps occlude in the central fossae of the opposing

Question 22

posterior crossbite

Answer 22

mandibular lingual cusps in central fossae
maxillary buccal in central fossa
opposite of normal
- the functional switch

Question 23

Buccooclusal line

linguocclusal line

Answer 23

connects buccal cusps

connects lingual cusps in arch

Question 24

outer functional cusp inclines

Answer 24

the functional OUTER ASPECT of the centric cusp is the only area of an outer incline with functional significance - it is GUIDING
GUIDE THE CUSP INTO THE MIP

Question 25

functional cusp inclines (three)

Answer 25

supporting - INNER guiding - OUTER SURFACE guiding - INNER

Question 26

Guiding inclines of maxillary

Answer 26

guiding inclines of the maxillary teeth are the surfaces responsible for the characteristics of anterior guidance

Question 27

occlusal table

Answer 27

area of major forces of mastication

Question 28

chewing surface

Answer 28

this is NOT cusp tip to cusp tip - in the fossa - could be 50-60% of occlusal table

Question 29

four determinants of mandibular motion

Answer 29

1. right condyle 2. left condyle 3. muscles 4. dentition

Question 30

Class I

Answer 30

Orgonathic Profile occurs 72% of time MB cusp of the maxillary first molar is aligned directly over the buccal groove of mandibular 1st molar

Question 31

Class II

Answer 31

Mesial buccal cusp of maxillary first molar is in the ebrasure area between the mandibular 2nd premolar and 1st manddibular molae Protruded maxilla and retruded mandible excessive overjet or horizontal overlap

Question 32

Class II Division 1

Answer 32

proclined (flared out) maxillary anteriors - lower lip can be behind the maxillary anteriors and push them outward

Question 33

``` class ii division ii implications ```

Answer 33

maxillary anteriors pushed lingual or straight results in steep anterior guidance

Question 34

what type of lever is our jaw?

Answer 34

Class III lever - like a stapler and have the effort BETWEEN the fulcrum (condyle) and the load

Question 35

Class II occlusion

Answer 35

Distal occlusion

Question 36

Class III occlusion

Answer 36

MB cusp of the maxillary first molar occludes in the embrasure area between the mandibular 1st and 2nd molar Mesial occlusion with anterior crossbite prognathic profile

Question 37

what surfaces of the teeth are responsible for guiding the cusps in lateral movements?

Answer 37

outer surfaces of functional cusps | inner surfaces of the guiding

Question 38

angles class i - anterior teeth

Answer 38

``` vertical overlap (2-3 mm) horizontal overlap (minimal) ``` responsible for anterior guidance (diocclusion of posterior teeth and interferences)

Question 39

angles class iii - anteriors

Answer 39

edge to edge or anterior crossbite