TMJ Biomechanics - 2 Flashcards
blank joints with each movement of tmj
4
this separates upper and lower joint of tmj
temporomandibular disc
type of joint made by mandibular condyle and inferior surface of disk
hinge
type of joint made by articular eminence and superior surface of disk
planar
tmj is a blank joint without blank and instead has blank
synovial, hyaline, fibrocartilage
orientation of disc
thick, thin, thick
poles of mandibular condyle
lateral, medial
unable to palpate blank pole
medial
coronoid process is only palpable when mouth is blank because it goes under blank arch when blank
open, zygomatic, close
muscle attaching to coronoid process
temporalis
temporalis bone has a blank where the blank sits
glenoid fossa, mandibular condyle
articular eminence of temporalis bone is blank bone
trabecular
temporalis articular eminence on mandibular condyle is blank on blank
convex, convex
glenoid fossa on mandibular condyle is blank on blank
convex, concave
condyle at glenoid fossa is blank which means it cannot resist blank
thin/translucent, compression
contact when opening jaw occurs at the blank
articular eminence
articular eminence has blank cartilage
fibro
most fibrocartilage is found at articular eminence and anterosuperior condyle which shows that it blank
resists compression
deep fibers of articular eminence and condyle are aligned blank
perpendicular
superficial fibers of articular eminence and condyle are aligned blank for blank
parallel, shear forces
tmj is blank because it goes convex, concave, concave, convex
congruent
articular disk is blank to medial and lateral poles
firmly attached
articular disk is blank to medial and lateral capsule
not firmly attached
not firmly attached allows for blank
free rotation
articular disk is anteriorly attached to joint capsule and blank muscle
lateral pterygoid
lateral pterygoid muscle restricts blank
posterior translation
articular disk is attached posteriorly to blank
bilaminar retrodiskal pad
articular disk allows for anterior disk blank with mouth opening and repositioning of disk
translation
thickness goes blank anteriorly, blank posteriorly, and blank in the middle
2mm, 3mm, 1mm
anterior and posterior portions of articular disk are blank and blank
vascular, neural
middle portion of articular disk is blank and blank
avascular, aneural
middle portion of articular disk do not have nerves because it would hurt when blank
chewing
3 functions of articular disk
increased congruence of joint surface, shape allows disc to conform to bony surfaces with rotation and translation, thick thin thick arrangement centers the condyle on disk
increased pressure so disk rotation is between blank surfaces
articulating
decreased pressure causes joint blank
disarticulation
muscle that is fan shaped with extensive attachments inserting at coronoid process for elevation
temporalis
quadrilateral shaped muscle for elevation of tmj
masseter
elevates mandible only muscle
medial pterygoid
tmj muscle that rotates disc anteriorly on condyle with mouth closing
superior part of the lateral pterygoid
lower part of blank causes depression of tmj
lateral pterygoid
1 prime mandibular depression is the action of this muscle
digastrics (suprahyoids)
digastrics account for blank mm of opening
40-55
bilateral masseter, medial pterygoids and lateral creates blank of tmj
protrusion
medial and lateral pterygoids create blank
lateral deviation
medial pterygoids create blank lateral deviation
contra
lateral pterygoids create blank lateral deviation
ipsi
temporalis deviates tmj to blank side
ipsilateral
mouth opening there is initial blank roll of condyle followed by blank translation of disk and condyle nearing opening
anterior, anterior/inferior
instantaneous center of rotation shifts blank during opening
anterior
mouth opening there is initial blank translation of disk followed by blank roll of condyle nearing opening
posterior/superior, posterior
instantaneous center of rotation shifts blank during mouth closing
posterior
during mandibular protrusion and retrusion there is bilateral condyle translation blank/blank or blank/blank along articular eminence
anterior/inferior, posterior/superior
left lateral deviation there is left condylar and disk blank about a vertical axis combined with right condylar blank translation or gliding
spin, anterior
firm approximation of dentition is called blank position
occlusal
pathomechanics of tmj are secondary to direct blank such as … name 3
trauma
poor posture, clicking, locking, osteoarthritis
reciprocal click is caused by blank displacement of the disk
anteromedial
reciprocal click is noted on blank and a second click upon blank
opening, closing
reciprocal click is noted with blank upon opening
disk contact
locking is when only blank occurs with no anterior or posterior blank of the condyle
roll, translation
aka grinding teeth
bruxism
due to altered compressive and shear loading of tmj
osteoarthritis
osteoarthritis is usually blank
unilateral
loss blank teeth can lead to osteoarthritis more quickly
posterior