OB10 - Mastication - Mechanisms Flashcards
(21 cards)
what is the role of mastication?
- breakdown foodstuff
- Stimulation of salivary flow
- Growth and maintenance of oro‐facial tissues
why would you need to breakdown foodstuff?
- preparation for swallowing
- increase surface area for chemical digestion
- release of chemicals for sense of taste
What teeth do you need in a functional occlusion?
at least 5-5
Describe the mechanics of ingestion (4)
- Stage 1 transport- food from lips to cheek teeth
- Mastication
- Stage II transport- food from cheek teeth to back of tongue
- Swallowing
what are the jaw movements during mastication?
chewing cycyle
what are the tongue movements during mastication?
– directing food
– crushing food
– mixing food and saliva
what are the cheek movements during mastication?
directing food
what are the lip movements during mastication?
– retaining food : Anterior Oral Seal – directing food
what is the duration of the chewing cycle?
0.5-1.2 secs
what are the phases of chewing cycle?
- opening
- fast closing
- power closing
- slow closing
- intercuspal
During chewing describe the movement of the condyle on the working side during opening? (3)
- rotates around vertical axis
- moves slightly laterally (Bennett movement)
- very slight posterior movement
During chewing describe the movement of the condyle on the non working side during opening? (2)
- moves downwards, forwards and medially
- described by Bennett angle
During chewing describe the movements of the condylar head on the working side whilst closing?
- moves medially to normal position in glenoid fossa
- rotates back to normal rotation
During chewing describe the movements of the condylar head on the non working side whilst closing?
- moves upwards, backwards and laterally
- returns to normal position in the glenoid fossa
Describe the sequence of muscle activation in opening whilst chewing (3)
- mylohyoid
- digastric
- lateral pterygoid
Describe the sequence of muscle activation in closing whilst chewing (3)
- temporalis
- masseter
- medial pterygoid
what are the physiological chewing forces?
- 70-150N dentate
- 4-55N edentulous
what are the maximum clenching forces?
500-700N between molars
what are the factors leading to a preferred side for chewing?
- determined early in life and persists in spite of tooth loss
- whether side is dentate, partially dentate or edentulous
- restored with a fixed or moveable prosthesis
- pain / pathology ‐ avoidance
- occlusal interference
What is the name for experimental tests to define the capacity to reduce the size of food particles by chewing?
Masticatory Efficiency
what factors effect masticatory performance?
- number of teeth in functioning occlusion
- replacement of teeth
