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Flashcards in oral functions 3 Deck (60)
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define ingestion

movement of food from the external environment into the mouth


how does ingestion happen

accomplished by biting (anterior teeth) and / or using "tools" such as cutlery


what role does lips play in ingestion

they provide an anterior oral seal
cant control food in the mouth without the muscles around the lips
- orbicularis oris
- buccinator
(prevent spillages)


what is stage 1 transport

moving material from the front of the mouth to the level of the posterior teeth
food is gathered on tongue tip


what happens in stage 1 transport

the tongue retracts
pulling the material to the posterior teeth
(pull back process)
takes about 1 second

associated with the retraction of the hyoid bone and narrowing of the oropharynx


define mechanical processing

some solid foods must be broken down and mixed with saliva before they can be swallowed


what happens to moist solid food like fruit before transport and swallowing

needs to have the fluid removed


what teeth chew the food

premolar and molars
(although molars are not always needed - prosthetic dentistry)


what happens to some soft foods in mechanical processing

they are squashed by tongue against the hard palate
so the tongue is involved in chewing


what happens to the hyoid bone in chewing

it retracts


what does food processing involve

the co-ordinated actions of the following muscles
> mandibular muscles (also called the muscles of mastication)
> the supra-hyoid muscles
> tongue muscles
> the lips and cheeks


what are the 2 types of tongue muscles

- intrinsic
- extrinsic


what is the function of intrinsic tongue muscles
name these

alters the shape
- longitudinal
- vertical
- transverse


what is the function of extrinsic tongue muscles and name these

alters shape and position
- genioglossus
- hyoglossus
- palatoglossus
- styloglossus


what are the tongues actions in chewing

- controls the bolus
- gathers good and rotates to reposition the bolus on the occlusal table
- the tongue along with the cheeks, keeps the bolus on the chewing surfaces
- the tongue and cheeks act in a reciprocal manner to place the food on the occlusal surfaces of the teeth
- the tongue moves the bolus from side to side of the mouth
- tongue gathers the bolus for transport


what way should patients chew



what is the problem with chewing unilaterally

it is not good for the masticatory system
leads to problems with the masticatory muscles
hypertrophic muscles on one side of the face if chewing unilateral


what happens to the tongue during the occlusal and initial opening phases

the tongue moves froward
this creates a contact between the tongue and the hard palate


what is the squeeze back mechanism

> the contact (created during the occlusal and initial opening phases) moves progressively backwards
> squeezing the processed food through the fauces
[pushes the bolus so it is ready to be swallowed]
> the material accumulates on the pharyngeal surface of the tongue and remains until swallowing occurs


when is the mouth continuous with the oropharynx

during the processing of solid foods


what may be produced during the ingestion of liquids

posterior oral seals
liquids are swallowed from the mouth without stage 2 transport

watch video on SDEO


what are the phases in the chewing cycle

- opening phase
- closing phase
- occlusal phase


what happens in the opening phase of the chewing cycle

jaw depressor muscles are active


what happens in the closing phase of the chewing cycle

jaw elevator muscles are active


what happens in the occlusal phase of the chewing cycle

mandible is stationary / teeth are joined


what makes the chew cycle different

> different patients according to shape of teeth
> different patients according to presence or absence of tooth wear
> different foods


is the chewing cycle the same as the fossa envelope

the fossa envelope shows the broader movement of the jaw and mandible


what is the chewing cycle shape like when eating brittle food eg carrots

narrower / thinner shape


what is the chewing cycle shape when eating tough food eg meat

broader / wider shape


what does the chewing cycle look like in good occlusion

consistent shape
lines close together