mastication and ingestion

what is the role of mastication

breakdown of food

stimulation of salivary flow

growth and maintenance of orofacial tissues

what is the shortened dental arch

5-5 is needed for mastication

what is stage 1 of mastication

food goes to posterior teeth

what is stage 2 of mastication

food forms a bolus at the back of the tongue

what are the mechanics of mastication

movements of:

lip - retain (anterior oral seal) and direct food

jaw - chewing cycles

tongue - direct crush and mix food with saliva

cheek - direct food

what are the stages of mastication

opening

fast closing

slow closing

intercuspal phases

how long does chewing last for

0.5-1.2 secs

what is the bennett movement

shift of the mandible towards the working condyle

what s the bennett angle

condyle moves downwards then medially

what happens to the condyle during opening

working side - rotates vertical axis and laterally does bennetts movement

non working - moves downwards forwards over articular eminence eg bennetts angle

what happens to the condyle during closing

working side - moves medially to glenoid fossa

non working side - moves upwards backwards and laterally

what is the sequence of muscle activation in chewing when opening

mylohyoid

diagastric

lateral pterygoid

what is the sequence of muscle activation in chewing when closing

temporalis

masseter

medial pterygoid

what leads to a preferred side in chewing

determined in early life

dentate, partially dentate or edentulous

pain

prosthetics or restorations

what is the anterior oral seal

lips

what is the posterior oral seal

tongue and soft palate

1. Oral

2. Pharyngeal

3. Oesophageal

1. Oral

2. Pharyngeal

3. Oesophageal

what is oesophageal peristalsis

unidirectional wave of contraction down a tubular organ eg eosophagus

powerful; assisted by gravity when standing but can swallow upside down

how can you describe the process of food moving down the oesophagus

muscle contracts and pushes food bolus down and the lower part relaxes and repeats til it gets to the stomach

what is the prepatory phase of swallowing solid food

food is broken down/mastication

stage II transport

food accumulates on the posterior part of tongue

what comes after preparatory phase of swallowing

pharyngeal phase

oesophageal phase