oral functions 3: feeding Flashcards
what is ingestion?
movement of food from external environment into the mouth
accomplished by biting (anteriors) and/or using tools
lips provide anterior oral seal
which facial muscles help to control food bolus and prevent spillage?
orbicularis oris
buccinator
what is transport?
moving material from the front of the mouth to the level of the posterior teeth
what are the stages of transport?
food is gathered on tongue tip
tongue retracts, pulling the material to the posterior teeth
associated with retraction of the hyoid bone and narrowing of the oropharynx
what is mechanical processing?
some foods must be broken down and mixed with saliva before they can be swallowed
moist foods eg fruit must have fluid removed before tx and swallowing
how is food mechanically processed?
foods chewed (masticated) by premolar and molar teeth some soft foods are squashed by tongue against hard palate
what muscles are involved in food processing?
mandibular muscles
supra-hyoid muscles
tongue muscles
lips and cheeks
what are the tongue actions in chewing?
tongue controls the bolus
tongue gathers food and rotates to reposition the bolus on the occlusal table
along with cheeks it keeps the bolus on the chewing surfaces
tongue moves bolus from side-to-side of the mouth
gathers for transport
describe the tongue/cheek actions
tongue and cheeks act in a reciprocal manner to place the food on the occlusal surfaces of the teeth
tongue-pushing and cheek pushing cycles are observed
describe the process of tongue -> oropharynx
material accumulates on the pharyngeal surface of the tongue and remains there until swallowing occurs
during process of solid foods, the mouth is continuous with the oropharynx
posterior oral seal may be produced during the ingestion of liquids
where are liquids swallowed from?
mouth
-oral seal
where are solids swallowed from?
oro-pharynx
-no oral seal
what happens during swallowing?
moved rapidly through the hypopharynx past the laryngeal inlet
what are the phases of the chewing cycle?
occlusal phase-mandible stationary, teeth joined opening phase -jaw depressor muscles are active closing phase -jaw elevator muscles are active
what can cause variations in chewing cycles?
chewing on a brittle food (carrot) appears to create a broader stroke than chewing on cheese
chewing gum produces an even broader and wider chewing stroke
occlusal conditions has a marked effect on the chewing stroke
when is chewing style considered in dentistry?
when designing prostheses
what should you do if the px performs ruminatory mandibular movements to balance articulation?
use teeth w/ cusps to achieve balanced occlusion
-esp. when px have favourable ridge form
what does dentures with flat (evenly worn) occlusal surfaces suggest?
vertical mandibular movements (chopping)
cuspless teeth may be used
why are tongue movements considered when designing a prostheses?
inaccurate placement of mandibular posterior teeth might interfere with tongue’s movements and compromise the retention and stability of the denture
why is mechanical breakdown (chewing) of food necessary?
facilitates swallowing
might improve digestive efficiency in GIT
what is sufficient to ensure adequate digestion of most foods?
minimum chewing with a good dentition
what can deteriorates masticatory performance result in?
dietary restictions
- avoid difficult foods
- eg green veg, meat
- no evidence poor mastication causes malnutrition in people with GIT disorders
what is a shortened dental arch?
20 teeth considered the minimum for acceptable:
- masticatory function
- aesthetics
- maintenance of oral hygiene
what is the shortened dental arch concept?
absent molar teeth are only replaced if their absence gives rise to problems
SDA provides sufficient occlusal stability
SDA provides satisfactory comfort and appearance
chewing and comfort not significantly enhanced by RPDs
