TMJ - drolinger Flashcards
tmj is the articulation of
squamous portion of temporal bone and condyle of mandible
tmj is what 2 types of synovial joints
ginglymoid (hinge) annd arthroidial (gliding)
the tmj is classified as a compound joint but it only has two bones. what qualifies it as a compound joint?
the articular disc serves as a non ossified bone that allows for complex movements of the joint
t/f. you need to fix all cases with unaligned condyles
false. if theyre asymptomatic, you could cause more problems if you tried to fix it. also, most people’s condyles are out of line
what does squamotympanic fissure do
provides attachment for the joint capsule and the retrodiscal pad
t/f. articular surface is hyaline cartilage
FALSE! it is avascular fibrous connective tissue with main loadbearing area on the lateral aspect of the condyle
why is the fibrocartilagenous zone important
it is the only zone that allows the joint to regenerate and fix itself
t/f. the central part of the articular disc is avascular and aneural, whereas the peripheral areas are vascular and innervated
true.
location of band of articular disc in relation to condyle
anterior - thick, anterior
intermediate - thin, on articular eminence
posterior - thick, superior
t/f. the anterior portion of the articular disc is connected to the condyle.
false. it is attached to the superior head of the lat pterygoid. the med/lat portions of the disc are attached to the condyle
3 parts of the bilaminar zone
superior lamina (elastic fibers), retrodiscal pad (highly vascular and innervated), and inferior lamina (collagen fibers)
what is the bilaminar zone?
highly distortable organization of fibers that is located posterior to the articular disc
part of the tmj that allows translation
superior compartment (between temporal bone and articular disc)
part of the tmj that allows rotational movement
inferior compartment (between articular disc and condyle)
t/f. the tmj capsule is lined by a highly vascular synovial membrane
true.
t/f the ligaments of the tmj are composed of collagenous connective tissue and will stretch.
false. they will NOT stretch
outer oblique ligament (o/i/a)
largest band of the temporomandibular ligament that limits the opening of the mandible;
o: articular tubercle; i: inferior condyle
inner horizontal ligament (o/i/a)
smallest band of the temporomandibular ligament that limits the posterior movement of the disc and condyle;
o: articular tubercle; i: lateral part of the condyle and disc
stylomandibular ligament (o/i/a/composition)
o: styloid process; i: post margin of mandibular ramus; limits anterior protrusion; thick, deep cervical fascia
sphenomandibular ligament (o/i/a/composition)
o: spine of sphenoid; i: lingula of the mandible; pivot that maintains the same amount of tension during opening and closing; remnants of meckles cartilage
arterial supply of the tmj
superficial temporal
deep auricular artery
anterior tympanic
venous drainage of the tmj
superficial temporal
maxillary
innervation of tmj
V3:
auriculotemporal (sensory)
masseteric
post deep temporal (motor)
sensory pathway
1st order: receptive field to brainstem via CNV
2nd order: synapse in the trigeminal nucleus in brainstem
3rd order: terminates in primary somatosensory cortex
muscles that open mouth
lat pterygoid
suprahyoid
infrahyoid
muscles that close mouth
temporalis
masseter
medial pterygoid
muscles that protrude mand
masseter
lat/med pterygoid
muscles that retrude mandible
temporalis
masseter (deep fibers)
chewing muscles
ipsilateral temporalis
contralateral pterygoid
masseter
muscles that most commonly attach to art disc
lat pterygoid
midmed bundle of temporalis
muscles that occasionally attach to art disc
discotemporal bundle of temporalis
zygomaticomandibularis
masseter
direction of vector of force moving the mandible
anterior and medial
2 movements of opening mandible
rotation and translation
