Lecture 12 Determinants of Occlusal Morphology I

Question 1

what are the factors that determine the patterns of mandibular movements

Answer 1

-TMJs
- anterior teeth

Question 2

to maintain harmony the posterior teeth need to pass close to but _____ the opposing teeth during mandibular movement

Answer 2

not contact

Question 3

what are the structures that control mandibular movement

Answer 3

-TMJs influence posterior movement of mandible
- anterior teeth influence anterior movement of mandible

Question 4

what is the condylar guidance angle

Answer 4

the angle at which the condyle moves away from the horizontal plane

Question 5

condylar guidance is considered to be a _____

Answer 5

“fixed factor”

Question 6

as the mandible protrudes or moves laterally the incisal edges of the mandibular anterior teeth occlude with ____

Answer 6

the lingual surfaces of the maxillary anterior teeth

Question 7

what determines the amount of vertical movement of the mandible

Answer 7

the steepness of the lingual surfaces

Question 8

the anterior teeth determine how____

Answer 8

the anterior portion of the mandible moves

Question 9

the anterior guidance is considered to be a _____

Answer 9

variable factor

Question 10

what is the morphology of the tooth influenced by

Answer 10

the pathway it travels across its opposing tooth or teeth

Question 11

what are the components of mandibular movement

Answer 11

vertical component
horizontal component

Question 12

the length of a cusp and the distance it extends into the depth of an opposing fossa depends on:

Answer 12

1. anterior controlling factor of mandibular movement
2. posterior controlling factor of mandibular movement
3. the nearness of the cusp to those controlling factors

Question 13

what do vertical determinants control

Answer 13

-the function of the superior inferior movenet
- cusp height and fossa depth

Question 14

what do horizontal determinants influence

Answer 14

the direction of grooves and ridges on the occlusal surfaces and the placement of the cusps in the horizontal plane

Question 15

what are the vertical determinants

Answer 15

-condylar guidance
-anterior guidance
-nearness of the cusp to the controlling factor
- plane of occlusion
- curve of spee
mandibular lateral translation movement

Question 16

what are the posterior controlling factors

Answer 16

-fixed factors
- condylar guidance
-TMJs

Question 17

as the mandible is protruded the condyle descends along ____

Answer 17

the articular eminence

Question 18

is the condylar guidance angle greater when the mandible makes a lateral movement or when the mandible makes a protrusive movement

Answer 18

when the mandible makes a lateral movement

Question 19

the steeper the eminence:

Answer 19

• the more the condyle must move inferiorly
• there is greater vertical movement
• allows for steeper posterior cusps

Question 20

what is anterior guidance altered by

Answer 20

-restorations
-orthodontics
-extractions
-caries
- habits
-tooth wear

Question 21

what is the anterior guidance angle

Answer 21

the angle formed by the intersection of the horizontal plane and the disclusive pathway of the anterior teeth

Question 22

what is the anterior guidance angle influenced by

Answer 22

vertical overlap and horizontal overlap

Question 23

what does increased VO do to anterior guidance angle? increased HO?

Answer 23

increased VO: increases it
increased HO: decreases it

Question 24

the nearer a tooth is to the TMJ, the ____ the joint anatomy will influence its ecentric movement and the ____the anterior teeth influence its movement

Answer 24

more; less

Question 25

what are other factors that influence cusp height

Answer 25

-plane of occlusion -curve of spee - mandibular lateral translation movement

Question 26

as the plane of occlusion becomes more parallel to the angles of eminence the posterior cusp tips must be made _____

Answer 26

shorter

Question 27

what is the curve of spee

Answer 27

-anteroposterior - curve extending from the tip of the mandibular canine along the buccal cusp tips of the mandibular posterior teeth

Question 28

with a short radius the curve will be more _____ than with a longer radius

Answer 28

acute

Question 29

the flatter the plane of occlusion the ____the cusp height can be

Answer 29

greater

Question 30

if the curve of spee has a short radius: the angle at which the mandibular teeth move away from the maxillary teeth will be ____ than with a long radius , therefore the cusps will need to be _____

Answer 30

less; shorter

Question 31

if the plane of occlusion is rotated more anterior:

Answer 31

-more teeth anterior to perpendicular line - taller cusps

Question 32

if the plane of occlusion is rotated more posterior

Answer 32

-more teeth posterior to perpendicular reference line -shorter cusps

Question 33

what is the bennett movement

Answer 33

the mandibular lateral translation is a sideshift of the mandible during lateral movements

Question 34

what does how much inward movement there is depend on

Answer 34

-morphology of the medial wall of the fossa on the orbiting side inner portion of the TM ligament attached to the lateral pole of the rotating condyle

Question 35

describe the TM ligament

Answer 35

-very tight - pure arcing movement around the rotating condyle - no lateral translation of the mandible -not common

Question 36

in lateral translation movement, the more medial the medial wall is from the condyle___

Answer 36

the more lateral translation movement

Question 37

the lateral translation movement is described in

Answer 37

-amount -timing -direction

Question 38

the greater the amount of lateral translation the ____the posterior cusps must be

Answer 38

shorter

Question 39

what does laterosuperior movement require about cusp tips

Answer 39

shorter

Question 40

what does lateral inferior movement allow about cusp tips

Answer 40

taller

Question 41

what is the greatest influence on occlusal harmony

Answer 41

lateral translation timing

Question 42

what is early translation called

Answer 42

immediate lateral translation or immediate shideshift

Question 43

what is late lateral translation called

Answer 43

- progressive lateral translation or progressive sideshift

Question 44

when is immediate lateral translation seen

Answer 44

before the condyle begins to translate from the fossa

Question 45

the more immediate the movement the -___the cusps must be

Answer 45

shorter

Question 46

the steeper the condylar guidance:

Answer 46

the taller the cusps

Question 47

the greater the vertical overlap:

Answer 47

the taller the cusps

Question 48

the greater the horizontal overlap

Answer 48

the shorter the cusps

Question 49

the more parallel plane of occlusion to condylar guidance

Answer 49

the shorter the cusps

Question 50

the more acute the curve of spee:

Answer 50

the shorter the cusps

Question 51

the greater the lateral translation movement:

Answer 51

the shorter the cusps

Question 52

the more superior movement of the rotating condyle

Answer 52

the shorter the cusps

Question 53

the greater the immediate side shift:

Answer 53

the shorter the cusps