Major functions of the masticatory system Flashcards
What are three major functions of the masticatory system?
- Mastication
- Swallowing
- Speech
What is the pool of neurons within the brainstem of the CNS that controls rhythmic muscle activities?
Central pattern generator
T/F
Mastication is a learned and repeated pattern (muscle engram)
True
What are the two phases of mastication?
- Opening
- Closing
What phase deals with crushing and grinding?
Closing phase
How wide does the intercuspal position go in the opening phase of mastication?
16-18 mm
During the crushing phase where does the intercuspal position go to?
From 16 -18 to 3 mm apart
How far lateral of the starting position does the crushing phase go?
3-4 mm
T/F Buccal cusps of maxillary teeth are almost directly under the buccal cusps of the mandibular teeth on the side to which the mandible has been shifted.
False
The mandibular teeth are under the maxillary teeth
When you close what position do the teeth go?
Intercuspal position
What is the grinding phase?
It is the continuation of the closure phase
T/F cuspal inclines pass across each other
True
T/F
The harder the food, the more lateral the closure stroke
True
T/F
The harder the food, the less chewing strokes are needed
False
More chewing strokes needed
T/F
There are many contacts when food is first introduced into the mouth.
False
There are very few contacts at first
What is the avg. length of time for tooth contact during mastication?
194ms
Tall cusps and deep fossae promote what type of chewing strokes?
Vertical
Flattened or worn cusps promote what type of chewing strokes?
Broader
What produces irregular and less repeatable chewing strokes?
Malocclusion
What are the avg biting forces in females?
79-99lbs
What are the average biting forces for males?
118-142 lbs
What are the forces of mastication on the first molars?
91-198 lbs
What are the forces of mastication on the central incisor?
29-51 lbs
T/F
Dentures give you about 1/4 biting force as natural teeth.
True
T/F
Lips guide and control intake as well as seal off oral cavity
True
What does the tongue do in mastication?
- Taste
- Move food
- Divide food
- Sweeps teeth to remove trapped food
T/F
Cheeks (buccinator muscles) work in harmony with the tongue to position food back onto the occlusal surfaces for next chew stroke
True
What type of swallow: adult uses teeth for mandibular stability
Somatic swallow
What type of swallow: infant or edentulous uses tongue forward and between the dental arches
Visceral swallow
What is the duration of swallowing?
683 ms
T/F
Variations in sound are created by relationships of the lips and tongue to the palate and teeth
True
