Temporomandibular Joint

Question 1

Osseus segments of the mandible

Answer 1

mandible moves on the stationary maxilla

maxilla is not part of TM joint

Question 2

osseus segments of the temporal bone

Answer 2

temporal bone is stationary during mandible depression

function: function is to attatchment for TM joint musculature

Question 3

osseus segment of TM Joint

Answer 3

synovial joint formed by condyle of mandible and the articular eminence of temporal bone

function: self repair and remodel

Question 4

What are the accessory Joint structures of the TM joint ?

Answer 4

articular discs to increase stability , minimize mobility, and reduce friction

thickeness will be anywhere from 2mm anteriorly to 1mm in center to 3mm posteriorly

Question 5

TM joint capsule

Answer 5

thin and loose capsule

strongest along lateral aspect

Question 6

ligaments of the TM joint

Answer 6

TM ligament
Stylomandibular ligament
sphenomandibular ligament

function is to primarily stabilize upon opening

Question 7

What muscles close the mouth ?

Answer 7

temporalis
masseter
medial pterygoid

Question 8

what muscles open the mouth?

Answer 8

lateral pterygoid

Question 9

what muscles protrude the mandible ?

Answer 9

lateral pterygoid

Question 10

what muscles retract the mandible?

Answer 10

temporalis

Question 11

what movements does the TM joint do?

Answer 11

rolling , anterior slide, distraction, and lateral glide

mandible depression and elevation, protrusion or retrsion, left right excursions

Question 12

Kinematics of depression and elevation

Answer 12

anterior slide and anterior spin

ROM 40 to 50 mm when measured tooth to tooth

normal: pip joints of 3 fingers can fit

Question 13

kinematics of protrusion and retrusion

Answer 13

condyle disc complex translates anterior inferior direction

important for mandible depression

ROM 6 to 9 mm

Question 14

kinematics of mandibular lateral excursion

Answer 14

moving mandible to left and right

ROM 8 to 11 mm

Question 15

What is the relationship to the cervical spine and posture?

Answer 15

prox and distal attatchments of the TM muscles show both direct and indirect connections to the cerv spine , throat, clavicle, scapula

Question 16

what are the two temporomandibular dysfunctions?

Answer 16

disc displacement with and without reduction

occurs when articular disc subluxes beyond the articular eminence

Question 17

disc displacement with reduction

Answer 17

experience joint noise on two intervals

the reciporical click is the gold standard for diagnosis

Question 18

disc displacement without reduction

Answer 18

the disc does not relocate onto the mandibular condyle

inability to fully open mouth , difficulty chewing talking or yawning

Question 19

What causes temporomandiublar dysfunction?

Answer 19

hyperactivity or spasm of lateral pterygoid
(hypertophy or contracture)

results in excessive anterior translation of the articulation disc