DETERMINANTS OF OCCLUSAL MORPHOLOGY I

Question 1

The factors that determine the patterns of mandibular movement are…

(aka control mandibular movement)

Answer 1

1) temporomandiublar joints (TMJs)
—structures that influence the movement of the posterior portion of the mandible

2) anterior teeth
–structures that influence the movement of the anterior portion of the mandible (this contact tells mand how to move)

Question 2

to maintain harmony, the ____ teeth need to pass close to but not contact the opposing teeth during __

Answer 2

posterior teeth; mandibular movement

(don’t do well with lateral forces)

Question 3

Posterior controlling factors:

The angle at which the condyle moves away from a horizontal reference plane is refered to as…

Answer 3

condylar guidance angle

considered to be a “fixed factor”

Question 4

Posterior controlling factors:

Why is condylar guidance is considered to be a fixed factor?

Answer 4

In a healthy patient it is unalterable

Question 5

Anterior controlling factors/Anterior Guidance:

The steepness of the _______ surfaces determine the amount of ___ movement of the mandible

Answer 5

lingual; vertical

Question 6

The anterior guidance is considered to be a ____ factor

Answer 6

variable

Question 7

Anterior Controlling Factors (anterior guidance):

as the mandibular protrudes or moves laterally, the incisal edges of the mandibular anterior teeth occlude with the …

Answer 7

lingual surfaces of the maxillary anterior teeth

steep anterior teeth=more vertical movement
flat anterior teeth=less vertical movement

Question 8

Anterior controlling factors:

how can the anterior guidance of the mandible be changed?

Answer 8

it can be altered by pathologic conditions (caries, wear) or
dental procedures

more surface=more movement, more guidance

Question 9

The morphology of the tooth is influenced by the pathway it travels across…

Answer 9

its opposing tooth or teeth

the morphologic characteristics of each posterior tooth must be in harmony with those of its opposing tooth or teeth during all mandibular eccentric movements

Question 10

What is the vertical component of mandibular movement?

Answer 10

supero-inferior movement

Question 11

What is the horizontal component of mandibular movement?

Answer 11

antero-posterior movement

Question 12

Vertical Component–function of superio-inferior movement

We want posterior teeth to pass close to, but not contact opposing teeth during mandibular movement…what is this called?

Answer 12

Occlusal Harmony

–want to *barely miss eachother
–if hit=interference –> TMJ pain

Question 13

Vertical component

The length of the cusp and the distance it extends into the depth of an opposing fossa depends on…

Answer 13

1. anterior controlling factor of mandibular movement (teeth)
2. posterior controlling factor (condyle)
3. the nearness of the cusp to those controlling factors (?teeth and condyle?)

Question 14

What do horizontal determinants of mandibular movements influence?

Answer 14

direction of the grooves and ridges on the occlusal surfaces and the placement of the cusps in the horizontal plane (placed in a position so don’t hit eachother)

Question 15

What does vertical determinants of mandibular movements influence?

Answer 15

control the function of the superior-inferior movement:
1) cusp height
2) fossae depth

Question 16

What are the vertical determinants?

6 listed in lecture

Vertical determinants influence 1) cusp height 2) fossae depth

Answer 16

• condylar guidance (posterior controlling factor)
• anterior guidance (anterior controlling factor)
• nearness of cusp to controlling factor
• plane of occlusion
• curve of spee
• mandibular lateral translation movement

Question 17

What are the aspects of the posterior controlling factors?

Answer 17

• fixed factors
• condylar guidance
• anatomical structure of the two TMJs (artic eminence and medial wall of artic fossae)

Question 18

What is the condylar guidance?

Answer 18

• the angle at which the condyle moves away from the horizontal reference plane
• as the mandibule is protruded the condyle descends along the articular eminence

Question 19

Condylar Guidance:

• as the mandibule is protruded the condyle descends along the ____

Answer 19

articular eminence

mand forward=condyle in eminence

Question 20

Condylar Guidance:

when the mandible makes a ___ movement, the condylar guidance is greater than when the mandible makes a _________ movement

Answer 20

lateral movement > protrusive movement

Question 21

Condylar Guidance:

The steeper the eminence, the _____ the condyle must move _______

–what does this allow for?

Answer 21

more the condyle must move inferiorly
(greater vertical movement)

–allows for steeper posterior cusps

Question 22

Condylar Guidance:

The steeper the angle of the eminence the steeper the…

Answer 22

posterior cusps of teeth

Question 23

What are the anterior controlling factors?

Answer 23

• anterior teeth (determine how anterior portion of mandible moves)
• anterior guidance

Question 24

What can alter anterior guidance?

Answer 24

• restorations
• orthodontics
• extractions
• caries
• habits
• tooth wear
• anterior guidance is variable! (not fixed..posterior is fixed)

Question 25

What is the definition of anterior guidance angle?

Answer 25

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

Question 26

What is the anterior guidance angle influenced by?

Answer 26

vertical overlap (VO) -- varies horizontal overlap (HO) -- stays the same

Question 27

What happens to the anterior guidance angle with an increased vertical overlap?

Answer 27

increased anterior guidance angle

Question 28

What happens to the anterior guidance angle with an increased horizontal overlap?

Answer 28

decreased anterior guidance angle

Question 29

What happens if you have an increased anterior guidance angle? What does it allow for?

Answer 29

- more vertical component - allows steeper the posterior cusps ## Footnote steeper angle=taller cusp

Question 30

# Nearness to controlling factors: The nearer a tooth is to the TMJ...

Answer 30

the **more** the joint anatomy will influence its eccentric movement and the **less** the anterior teeth influence its movement ## Footnote Different: closer to teeth = inclination of teeth influence

Question 31

****What are other factors that influence *cusp height*?

Answer 31

- plane of occlusion - curve of spee (AP) - mandibular lateral translation movement

Question 32

What is the plane of occlusion?

Answer 32

imaginary surface that touches the incisal edges of the incisors and cusp tips of the occluding surfaces of the posterior teeth

Question 33

As the plane of occlusion becomes **more parallel** to the angle of eminence, the *posterior* cusps must be made...

Answer 33

shorter

Question 34

What is the curve of spee?

Answer 34

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

Question 35

Described in terms of length of radius of the curve

Answer 35

Curvature

Question 36

The flatter the plane of occlusion the ______ cusp height

Answer 36

greater

Question 37

If the curve of spee has a short radius: the ANGLE at which the mandibular teeth move away from the maxillary teeth will be... --how does this affect cusp length?

Answer 37

more acute (less) than with a longer radius - cusps will need to be shorter ## Footnote less move=shorter cusps

Question 38

If the plane of occlusion is rotated more anterior... ## Footnote (more teeth anterior to perpendicular line)

Answer 38

--taller cusps

Question 39

If the plane of occlusion is rotated more posterior... ## Footnote (more teeth posterior to perpendicular reference line)

Answer 39

shorter cusps

Question 40

Effect of mandibular lateral translation movement on cusp height

Answer 40

Bennett Movement

Question 41

The mandibular lateral translation is a __________ _______ of the mandible during lateral movement

Answer 41

bodily sideshift

Question 42

What does the inward movement of the mandible depend on?

Answer 42

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

Question 43

the more medial the medial wall is from the condyle, the more ...

Answer 43

lateral translation movement

Question 44

If the temporomandibular ligament is very tight then...

Answer 44

- **no** lateral translation of mandible **- not common** - *pure arching* movement around the rotating condyle

Question 45

What is the lateral translation movement described in... ## Footnote name 3 descriptions

Answer 45

amount (how much?) timing (how fast?) direction

Question 46

The greater the amount of lateral translation the _______ the posterior cusps

Answer 46

shorter

Question 47

What are the movements that the rotating condyle makes?

Answer 47

- laterosuperior (req shorter cusps) - lateroinferoposterior (allows taller cusps) - etc.

Question 48

What has the greatest influence on occlusal morphology?

Answer 48

lateral translation timing

Question 49

What are the two types of condylar lateral translation timing?

Answer 49

early translation (before moves) late lateral translation (progress as moves down)

Question 50

# Condylar Lateral Translation: What is another name for early translation?

Answer 50

immediate lateral translation (immediate sideshift)

Question 51

the immediate lateral translation shift is seen ______ the condyle begins to translate from the fossa

Answer 51

before

Question 52

# Immediate Lateral Translation: --shift seen before the condyle begins to translate from the fossa the more the immediate movement the ________ the cusps must be

Answer 52

shorter

Question 53

# Condylar Lateral Translation: What is another name for late lateral translation?

Answer 53

progressive lateral translation (progressive sideshift) ## Footnote as mandible moves down

Question 54

If the condyle guidance is steep what cusps requires?

Answer 54

taller

Question 55

If anterior guidance is greater vertical overlap what cusps required?

Answer 55

taller

Question 56

If anterior guidance is greater horizontal overlap what cusps required?

Answer 56

shorter

Question 57

If plane of occlusion is more parallel to the condylar guidance what cusps required?

Answer 57

shorter

Question 58

If curve of spee is more acute than the curve what cusps required?

Answer 58

shorter

Question 59

If lateral translational movement is greater what happens to cusps?

Answer 59

shorter

Question 60

If lateral translational movement is more superior of the rotating condyle what happens to cusps?

Answer 60

shorter

Question 61

If lateral translational movement is greater than immediate side shift what happens to cusps?

Answer 61

shorter

Question 62

Answer 62

KNOW