Determinants of Occlusal Morphology Part 2--Horizontal Factors

Question 1

HORIZONTAL FACTORS influence (2)

Answer 1

1) the direction of the ridges and grooves on the occlusal surfaces
2) the placement of the cusps

Question 2

Mediotrusion:

THE MANDIBLE MOVES MEDIALLY:

i.e. right mediotrusion means that the right lateral condyle moves __

Answer 2

medially (same as left lateral movement)

NW path also called mediotrusive path

Question 3

the non working pathways are also called

Answer 3

mediotrusive pathways

Question 4

the mandible moves laterally:

i.e. right laterotrusion means that the right condyle moves ___

Answer 4

laterally (same as right lateral movement)

Working pathways also called laterotrusive pathways

Question 5

THE WORKING PATHWAYS ALSO ARE CALLED

Answer 5

LATEROTRUSIVE PATHWAYS

Question 6

HORIZONTAL FACTORS (4)

Answer 6

-distance from the rotating condyle
-distance from the midsagital plane
-amount of mandibular lateral translation
-intercondylar width

Question 7

Horizontal Factors:

effect of distance of the tooth from the (2)

Answer 7

-rotating condyle
-midsagittal plane

greater distance between tooth and rotating condyle = wider angle

Question 8

Effect of distance from the rotating condyle:

the greater the distance of the tooth from the rotating condyle,
the — the angle formed by the working and non-working
pathways.

Answer 8

wider

Same in the mandible and maxilla

Question 9

Effects of distance from midsagittal plane:

the greater the distance from the tooth from the midsagittal plane, the — the angle formed by the working and non working pathways

Answer 9

wider

same in mandible and maxilla

Question 10

Most of the times teeth that are closer to the midsagittal plane will be at

Answer 10

greater distance from the rotating condyle.

Question 11

Effect of distance from the rotating condyle and midsagittal plane:

Teeth that are positioned more anteriorly in the jaw (i.e. premolars)
tend to have greater angles between (2)
pathways compared to teeth that are positioned more posteriorly (i.e
molars).

Answer 11

mediotrusive and laterotusive

Question 12

The angle formed by the working and non-working pathways
increases as the amount of — increases.
The — of the lateral translation also influences the angle.
Same in the mandible and maxilla

Answer 12

lateral translation

direction

Question 13

Effect of intercondylar distance:

The angle formed by the working and non-working pathways

— as the intercondylar distance —.

Answer 13

DECREASES

INCREASES

Question 14

Know this chart

Answer 14

Know this Chart

Question 15

What does blue represent? Green? Orange?

Answer 15

Blue=working
Green=nonworking
Orange=protrusive

Question 16

another term for working interfering contacts is

Answer 16

laterotrusive contacts

Question 17

another term for non working interfering contacts is

Answer 17

mediotrusive contacts

Question 18

PHYSIOLOGY OF THE 
MASTICATORY SYSTEM (3)

Answer 18

mastication (chewing)
swallowing
speech

Question 19

-initial stage of digestion
-rhythmic separation and closure of the teeth control of the **central pattern generator **
-automatic/involuntary- can be controlled voluntarily

Answer 19

Mastication

Starts in MIP!!

Question 20

chewing stroke

Answer 20

-single condyle of opening and closing
-tear shaped pattern ?in frontal plane?

Question 21

Apects of the chewing stroke pattern

Answer 21

tear shaped pattern (frontal)

-Opening Phase
-Closing Phase
—crushing phase
—grinding phase

-begins and ends at MIP
–Tall cusps/Deep Fossae – more vertical chewing stroke

-most people have a preferred chewing stroke

Question 22

chewing stroke begins and ends in

Answer 22

MIP

Question 23

tall cusps/deep fossae

-more — chewing stroke

Answer 23

more vertical

Question 24

— occur during mastication

Answer 24

tooth contacts

Question 25

-tooth contacts occur during mastication increased frequency of contacts as food is broken down (2)

Answer 25

``` gliding contact (cuspal inclines) single contacts (MIP contacts) ```

Question 26

average length of time of contact=

Answer 26

194 ms

Question 27

``` maximal biting forces: forces vary (5) ```

Answer 27

``` male>female skeletal relationships and occlusion race (eskimos +++) anterior or posterior tooth (posterior=heavier) mastication or swallowing ```

Question 28

average max biting force

Answer 28

80-150 lbs (greatest was 975 lbs)

Question 29

Are forces for chewing greater or less than biting forces?

Answer 29

Less.. (36% of max biting) ## Footnote don't use all when chewing--only enough

Question 30

# Max biting forces: dentures=

Answer 30

1/4 that of natural teeth

Question 31

series of coordinated muscular contractions that move a bolus of food from the oral cavity through the esophagus to the stomach

Answer 31

swallowing

Question 32

swallowing includes both (2) muscle activity

Answer 32

voluntary, involuntary, and reflex muscle activity somatic/visceral swallow

Question 33

# Swallowing: mandible stabilized by

Answer 33

tooth contacts (MIP)

Question 34

# Swallowing: tooth contact=

Answer 34

683 ms

Question 35

# swallowing: lower levels of muscle activity if

Answer 35

MIP and CR are coincident

Question 36

# swallowing: swallow up to ---x per day

Answer 36

700 ## Footnote more contact=wear down

Question 37

``` swallowing: first stage (6) ```

Answer 37

voluntary control bolus of food is created lips are sealed tip of tongue rests against *hard palate* behind incisors teeth contact in MIP *reflex reaction* in tongue pushes food posteriorly into pharynx

Question 38

``` swallowing: second stage (4) ```

Answer 38

food bolus in pharynx contraction of pharyngeal constrictor muscles move food to esophagus (peristalsis) soft palate rises and seals off the nasal passages (nasopharynx)= *velopharyngeal seal* epiglottis seals off trachea

Question 39

``` swallowing: third stage (2) ```

Answer 39

-peristaltic waves move food into the stomach (6-7 s) -cardiac sphincter relaxes and food enters stomach

Question 40

speech:

Answer 40

controlled contraction and relaxation of the vocal cords as air moves through the larynx

Question 41

speech: | occurs during

Answer 41

expiration

Question 42

T/F: Teeth contact during speech

Answer 42

False--use this fact to help determine a patients correct OVD

Question 43

# Name the contacts:

Answer 43

Centric Occlusion Contacts

Question 44

Name the contacts:

Answer 44

Canine Guidance Contacts

Question 45

Name the contacts:

Answer 45

Group Function Contacts