N22 mastication mechanics Flashcards
what is the role of mastication?
breakdown of foodstuffs
- preparation for swallowing
- increase surface area for chemical digestion
- release of chemicals for sense of taste
stimulation of salivary flow
growth and maintenance of oro-facial tissues
how many teeth do you need for a shortened dental arch?
5-5 in functional occlusion
what are the mechanics of ingestion?
stage I transport
- food from lips to cheek teeth
mastication (chewing)
- (except for liquids)
stage II transport
- food from cheek teeth to back of tongue
swallowing
list the mechanics of mastication
jaw movements
- chewing cycles
tongue movements
- directing food
- crushing food
- mixed food and saliva
cheek movements
- directing food
lip movements
- accepting food
retaining food : Anterior Oral seal
directing food
chewing cycle
0.5 - 1.2 secs duration
phases - different terminologies
- opening, closing, occlusal phases
- opening, fast closing, power closing phases
- opening, fast closing, intercuspal phases
describe the movements of the condylar head during the chewing cycle - opening
working side head:
- rotates around vertical axis
- moves slightly laterally - bennett movement
- very slight posterior movement
describe the movements of the condylar head during opening of the non-working side head
- moves downwards, forwards and medially
- described by Bennett Angle
during closing - working side of condylar head?
- moves medially to normal position in Glenoid Fossa
- rotates back to normal orientation
non-working side head - movements of the condylar head? while closing
- moves upwards, backwards and laterally
- returns to normal position in Glenoid Fossa
what is the sequence of muscle activation
opening
- mylohyoid
- digastric
- lateral pterygoid
closing
- temporalis
- masseter
- medial pterygoid
