Oral Biology Flashcards
name the four muscles of mastication
masseter
temporalis
lateral pterygoid
medial pterygoid
name the origin, insertion and action of the masseter
origin - zygomatic arch
insertion - angle of mandible
action - elevation
name the origin, insertion and action of the lateral pterygoid
origin - lateral surface of lateral pterygoid head
insertion - condyle and intra-articular disc
function - protrudes and lateral deviates the mandible, also depresses!
name the origin, insertion and action of the temporalis
origin - floor of temporal fossa
insertion - coronoid process and anterior border of ramus
action - elevates and retracts
what muscle is most likely to be related to clicking of the TMJ
lateral pterygoid
how is the lateral pterygoid best tested
by testing the ability of the mandible to depress (mouth to open)
name the origin, insertion and action of the medial pterygoid
origin - lateral pterygoid plate and maxillary tuberosity
insertion - medial surface of mandible
action - elevates and protrudes mandible
what may accidentally cause trismus when giving a patient an IDB
hitting the medial pterygoid
what is the first movement of the mandible called upon opening
rotation - the condyle rotates on a hinge axis for the first 20mm of opening
what is the second movement in mandibular opening called when opening the mouth
translation - the wider opening of protrusive or retrusive movements (sliding)
what occurs in mandibular protrusion
both condyles leave the glenoid fossae and move forward along the articular eminences
what shape does the rotation and translation movements of the mandible form
envelope
what are the two types of muscle fibres
type I - slow low forces
type II - fast stronger forces
name the four suprahyoid muscles
digastric
mylohyoid
geniohyoid
stylohyoid
name the four infrahyoid muscles
sternohyoid
omohyoid
thyrohyoid
sternothyroid
what are the three intrinsic tongue muscles and their function
longitudinal, vertical and transverse
they alter shape of the tongue
what are the four extrinsic muscles of the tongue
genioglossus
hyoglossus
palatoglossus
styloglossus
they alter shape and position
what two facial muscles are associated with chewing and controlling the bolus in the mouth
buccinator
orbicularis oris
what sensory nerves are involved in innervating lower molars
trigeminal nerve - mandibular division - IAN
what might occur if the IAN is hit while administering an IDB
patient will feel an electric shock to half the lip
what are the five cranial nerves involved in the gag reflex
trigeminal
glossopharyngeal
vagus
accessory
hypoglossal
name four signs/ symptoms of Bell’s Palsy
inability to wrinkle brow
drooping eyelid
inability to puff cheeks
drooping mouth and food stuck in cheek
what are the five branches of the facial nerve
temporal
zygomatic
buccal
mandibular
cervical
what is Bell’s Palsy
any type of facial paralysis that does NOT have associated causes
what should patients be instructed to do when they have any type of facial paralysis
reassure them
eye protected with a loose pad until corneal blink reflex returns
what is the biggest advantage of keeping teeth/ roots for over dentures
periodontal mechanoreceptors - allow finer discrimination of food textures, tooth contacts and levels of functional loading
what is dysphagia
inability to swallow
name four causes of dysphagia
stroke
MS
GORD
tumours
what nerve supplies motor function to the tongue
hypoglossal nerve
what sensory nerve is the anterior 2/3rds of the tongue innervated by
lingual nerve (and chorda tympani)
what is the sensory innervation to the posterior 1/3rd of the tongue
glossopharyngeal nerve
what are the 3 stages in the feeding sequence
ingestion
stage I transport - chewing
mechanical processing
what is involved in ingestion stage of feeding
food moved from external environment to mouth
lips provide anterior oral seal
facial muscles control the food bolus
what is involved in stage I transport during feeding process
material moves from front of mouth to level of posterior teeth
food gathers on tongue tip and tongue retracts - pulling food to back of mouth
what is involved in the mechanical processing phase of the feeding sequence
solid foods mixed with saliva
some foods squashed by tongue against hard palate
what muscles are involved in food processing
mandibular muscles
supra-hyoid muscles
tongue muscles
lips and cheeks
name five actions of the tongue in chewing
controls the bolus
gathers food and rotates to reposition the bolus on occlusal table
keeps bolus on chewing surfaces
moves bolus from side to side in the mouth
collects bolus for transport at final stage
what is the squeeze back mechanism of food chewing
forward movement of the tongue during occlusal and initial opening phases creates contact between tongue and hard palate
the contact zone progressively moves posteriorly
this squeezes the bolus through the fauces
how are liquids ingested
liquids are swallowed from the mouth - without any stage II transport
where are solids swallowed from
oro-pharynx
what occurs to the chewing cycle in brittle compared to tough food
brittle (eg carrot) = narrow
tough (eg meat) = wider
what is suggested if a patient attends the dental practice with a denture that is evenly worn flat
vertical chopping movements
what denture teeth might be more suitable for people who have vertical mandibular movements
cuspless
what is a shortened dental arch
20 teeth (or functional units if a bridge is included) is the minimum number of units for acceptable masticatory performance, aesthetics and maintenance of oral hygiene
what occurs with respect to biting forces in complete denture wearers
biting forces are reduced
biting load is carried by mucosa of residual ridge - causes resorption with excessive forces
when is a cantilever bridge contraindicated
where there is heavy occlusal forces on the pontic
what are the three phases of swallowing
buccal phase (voluntary)
pharyngeal stage (involuntary)
oesophageal phase (involuntary)
what is the difference between swallowing food and swallowing liquid
liquid is swallowed from the mouth proper (oral seal)
food is swallowed from oro-pharynx (no oral seal)
what separates the mouth from the pharynx
posterior oral seal
what prevents reflux from stomach to oesophagus and from oesophagus to pharynx
stomach to oesophagus - lower oesophageal sphincter
oesophagus to pharynx - upper oesophageal sphincter
what is attrition
tooth wear caused by contact between occluding teeth (bruxists)
what is abrasion
most commonly tooth wear due to using too much abrasive force with a toothbrush
mainly seen on cervical area
what is dysphasia (WITH AN S)
language disorder which involves Broca’s and Wenicke’s area in the brain
what is dysphagia (WITH A G)
difficulty/ inability swallowing
what is odynophagia
person experiences extreme pain when swallowing
what is dysarthria
difficulty speaking caused by problems with the muscles used in speech
name five oral causes of speech and language defects
malocclusion
CLP
tongue related
dry mouth
loss of teeth - denture related
name three things that might affect the tongues function
tongue tie
partial atrophy of the tongue
tongue stud piercing
what are mandibular tori
benign neoplasms - bony overgrowths
only becomes a problem if patient requires lower partial denture
name two issues with denture design that can affect speech
denture base plate is too thick
artificial teeth not set properly
what problem with speech may a denture base that is too thick cause
patient inability to say ‘s’ sound and it all turns to ‘sh’ sounds
what problem with speech may occur when denture teeth are set in the wrong occlusal planes
problems making ‘f’, ‘v’ and ‘ph’ sounds
what is embouchure
position and use of lips, tongue and teeth when playing a wind instrument
