Oral Function Flashcards
what is the origin insertion and function of masseter
origin - zygomatic arch
insertion - lateral border of the ramus of mandible
function - elevation of mandible
what is the origin insertion and function of temporalis
origin - temporal bone
insertion - coronoid process of mandible
function - elevation and retraction of mandible
what is the origin insertion and function of medial pterygoid
origin - medial surface of ptyergoid plate
insertion - angle of mandible
function - elevation and protrusion of mandible
what is the origin insertion and function of lateral pterygoid
origin - lateral surface of pterygoid plate
insertion - condyle of mandible
function - depression, protrusion and lateral movement
how can the integrity of masseter be tested and what patients might find this sensitive
one finger intra-orally, one extra-orally, can feel bulk of muscle between. may be sensitive in those with clenching problems
how can the integrity of temporalis be tested and what patients might find this sensitive
ask patient to bite together, palpate at the tempal near eye. sensitive in patients with bruxism
how can the integrity of lateral pterygoid be tested
cannot be palpated as is too deep. but is sensitive to resistance movements. ask patient to depress mandible whilst pushing against, or ask to move jaw side wards while pushing against it. clicking of jaw suggests muscle spasm due to fatigue. splint will relax muscle
what causes trismus
damage to medial pterygoid muscle during ID block, muscle paralysed, unable to fully depress mandible due to lack of rotation
what are the movements of the TMJ
rotation and translation (sliding)
what shows the movement of TMJ
posselt’s envelope, shows the protrusion, opening and occlusion
where has maximum biting force
posterior teeth - closest to fulcrum
what are some possible complications with administrating an ID block
LA into muscle - medial pterygoid - trismus
LA into soft tissue, filtrate through to parotid gland - Bell’s palsy
LA into nerve - temporary trauma, blocked for longer than required, may get parasthesia - tingly sensation when it is being restored
what can be done for bells palsy patients
nothing can be done, no treatment, will resolve on it’s own with time. administer an eye patch as blinking reflex is not possible, need to protect cornea
what nerves are involved in the gag reflex
glossopharyngeal - afferent
uses interneurones then efferent
trigeminal, facial, glossopharyngeal, accessory, vagus, hypoglossal
how can patients with a gag reflex be managed
if require denture - avoid a post dam, anything too posterior will not be tolerated
when taking impressions - tilt head forward
put impression tray in at the back first, then move forwards
make impression material thick and with warm water to induce faster set
why is it important to retain roots even if not crowns for denture
PDL fibres with receptors
mechanoreceptors - provide sensory information about types of food, alters the mastication and force of muscles to tailor to food, jaw jerk reflex
interdental discrimination - can feel as small as a hair between teeth
proprioception - know the movement of jaw and mastication, without thinking about it
discrimination between foods, functional loading, control of mandibular movement, psychological benefit
what feature allows to recognise the mint in your mouth has a hole in the middle
two point discrimination - between tongue and hard palate
what can cause dysphagia and what would you do with a patient complaining of this
stroke, brain injury, tumour, ms
can rule out stroke by testing motor and sensory function - would be unilateral and forehead would be spared
refer to hospital
what are the stages of swalowing
ingestion, transport, mechanical processing
what is involved at the ingestion stage of swallowing
getting food into mouth, using anterior teeth to bite into smaller sizes
what is involved at the transport stage of swallowing
using posterior teeth to break into smaller sizes for swallowing, using tongue to move to back of mouth and side to side
what is involved in the mechanical processing stage of swallowing
when food is ready to be swallowed, put on tongue, this then moves back and up toward the hard palate, pushes against to break food bolus up more, as the contact zone moves posteriorly, the bolus in contact with the pharyngeal surface of the tongue, able to flow straight into oro-pharynx - squeeze back mechanism
what muscles are involved in swallowing
muscles of mastication, buccinator, orbicularis oris, tongue muscles, suprahyoid
what phases are involved in the chewing cycle
opening phase - jaw depressor muscles
closing phase - jaw elevator muscles
occlusal phase - ICP, muscles relaxed
what affects the chewing cycle
the hardness of food - soft food, wide cycle, hard food more narrow cycle
malocclusion - out of cycle
worn occlusion - wider cycle
when should the chewing cycle be considered
when designing a denture for a patient, if we know how they are used to eating, can alter the denture so this is maintained. sharp cusps - narrow cycle, more worn down - wider cycle
why might a shortened dental arch be recommended
if a patient has 20 teeth, healthy non carious, have maximum function, aesthetic, speech, may not have reason for restoration - unless absence causes problem. better oral hygiene than introducing prosthesis
what restoration has lowest biting force and which has highest
lowest - complete denture, mucosa borne only, cannot resist high forces, causes bone resorption
highest - implant, bone supported, still not PDL but can have denture off of this
what fixed appliances can be used for restorations
cantilever or fixed fixed bridge. involves crown prep on abutment teeth
what is adhesive bonded bridge
when the pontic is bonded to a surface of abutment teeth, instead of crown being used. cantilever or 2 abutment teeth. using this is dependant on health and condition of abutment teeth
what muscles are involved in changing the shape and position of the tongue
extrinsic - genioglossus, hyoglossus, palatoglossus, styloglossus
what are the intrinsic muscles of the tongue
vertical, transverse and longitudinal
what muscles are involved in chewing
suprahyoid muscles - stylohyoid, mylohyoid, digastric, geniohyoid, facial muscles - buccinator, orbicularis oris, muscles of mastication and tongue muscles
