Major Functions Of Masticatory System

Front 1

What are 4 functions of the masticatory system?

Back 1

1. Mastication
2. Swallowing
3. Speech
4. Respiration and Expression

Front 2

All the functional movements are ____ ______

Back 2

highly coordinated

Front 3

Where are 6 places sensory input comes from?

Back 3

1. teeth
2. periodontal ligaments
3. lips
4. tongue
5. cheeks
6. palate

Front 4

Where are all of the functional movements integrated?

Back 4

Central Pattern Generator (CPG)

Front 5

What is the CPG?

Back 5

A pool of neurons that controls rhythmic muscle activities and is responsible for the precise timing of activity between antagonistic muscles so that specific functions can be carried out

Front 6

What is a chewing stroke?

Back 6

rhythmic control separation and closure of teeth

Front 7

The chewing stroke is under control of what?

Back 7

the CPG

Front 8

What shape is the movement pattern?

Back 8

tear-shaped

Front 9

What are the two phases of closing movement?

Back 9

crushing and grinding

Front 10

Orbiting or _____ condyle or ______ condyle

Back 10

translating, nonworking

Front 11

Rotating condyle or ______ condyle

Back 11

working

Front 12

What happens to a nonworking condyle?

Back 12

it comes out of the TMJ

Front 13

What happens to a working condyle

Back 13

It stays in place, but rotates

Front 14

As the teeth approach each other, the later displacement is ______

Back 14

Lessened

Front 15

2 characteristics of chewing stroke on working side?

Back 15

1. incisors slightly anterior to intercuspal position at opening and returns from a posterior position

2. first molar traced on the side of the mandible moves, molar slighly anterior at opening and posterior at closing

Front 16

characteristics of chewing stroke on nonworking side

Back 16

1. first molar drops from intercuspal position vertically with little or no vertical movement
2. Final stage of the closing stroke is almost vertical
3. the condyle moves anteriorly during opening and follows the same pathway on its return

Front 17

During the chewing stage:
mandible moves (forward/backward) during incising.

Back 17

forward

Front 18

Less (forward/backward? movement needed after incision of food

Back 18

forward

Front 19

Crushing of food concentrated on (anterior/posterior) teeth

Back 19

posterior

Front 20

Movement of the 1st mandibular molar in the sagital plane varies according to what?

Back 20

the side the person is chewing on

Front 21

(Lateral/Vertical) movement of the mandible relates to the stage of mastication

Back 21

lateral

Front 22

Great (Lateral/vertical) movement when food is initially introduced in the mouth and less as food is broken

Back 22

Lateral

Front 23

T/F Lateral movement is the same no matter what the food consistency is.

Back 23

False, lateral movement varies according to food consistency

Front 24

What teeth is most chewing concentrated on?

Back 24

2nd premolar and 1st molar

Front 25

WHarder food creates ______ chewing strokes than soft food

Back 25

broader

Front 26

Chewing gum produces what type of chewing stroke?

Back 26

a wider, broader chewing stroke

Front 27

T/F The majority of people usually chew with one side

Back 27

T - usually the side with greater tooth contacts

Front 28

What is unique about chewing on one side?

Back 28

There is an unequal loading of the TMJ, but there is NO PROBLEM undernormal conditions

Front 29

Why is there no problem with the TMJ from unequal loading?

Back 29

The stabilizing effect of the superior lateral pterygoids on the discs

Front 30

(Many/Few) contacts occur during the intial stage of mastication.

Back 30

Few

Front 31

There is increase of tooth contacts as what happens?

Back 31

food is broken down

Front 32

Name two types of contacts

Back 32

1. gliding contact
2. single contact

Front 33

Gliding contact

Back 33

occurs as cuspal inclines pass each other during opening and grinding (close, then slide to completely close)

Front 34

Single contact

Back 34

occurs in maximum intercuspal position

Front 35

Maximum intercuspal position

Back 35

when your teeth come together completely

Front 36

Tooth contacts influence what two things?

Back 36

initial opening and final grinding phase of the chewing stroke

Front 37

Tall cusps and deep fossae would do what?

Back 37

promote pedominantly vertical chewing stroke

Front 38

Flattened of worn teeth would do what?

Back 38

promote a broader chewing stroke
BRUXER

Front 39

What happens if posterior contacts form an undesirable lateral movement?

Back 39

malocclusion produces an irregular and less repeatable chewing stroke

Front 40

T/F Females bite with more force than males.

Back 40

F Males do

Front 41

What is the maximum biting force reported?

Back 41

975 lbs (443 kg)

Front 42

T/F Incisors can take more force than molars.

Back 42

F Molars can take about 3 times more force than incisors

Front 43

T/F biting force increases with age up to adolescence

Back 43

T

Front 44

T/F Biting force can increase over time with practice

Back 44

T

Front 45

How much force can subjects with complete dentures apply?

Back 45

Only 1/4 of that of natural teeth

Front 46

What do the lips do in mastication?

Back 46

guide and control the intake of food
seal the oral cavity

Front 47

What is the tongue used for in mastication?

Back 47

to taste and maneuver the food within the oral cavity
also sweeps the teeth

Front 48

What do the muscles do in mastication?

Back 48

help position the bolus of food in the surfaces of the teeth (ex: buccinator)

Front 49

Swallowing

Back 49

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

Front 50

Two types of swallowing?

Back 50

Somatic and visceral

Front 51

Somatic swallow

Back 51

during swallowing teeth come together into maximum intercuspal position to stabilize the mandible

Front 52

During somatic swallowing, teeth come together to stabalize mandible for what?

Back 52

For the suprahyoid and infrahyoid to contract and control proper movement of hyoid in order to swallow

Front 53

Visceral swallowing

Back 53

Mandible is braced by placing the tongue forwarde and between the dental arches or gum pads.

Front 54

When would we see visceral swallowing?

Back 54

Occurs in infants (no posterior teeth) and adults with no teeth.

Front 55

Tooth contact occurs ___ times longer during swallowing than during mastication?

Back 55

3

Front 56

T/F The force applied during swallowing is weaker than during mastication

Back 56

F stronger

Front 57

Swallowing occurs how often in a 24 hour period?

Back 57

about 590 times

Front 58

M sound

Back 58

relaxed rest position

Front 59

What are between m sounds used for?

Back 59

to evaluate the amount of incisal display at rest

Front 60

F or V sounds

Back 60

length of central incisors and lingual tilt of incisal third

Front 61

s sound

Back 61

closest speaking space where the incisal and occlusal surfaces of teeth don't touch