TMJ

Question 1

Lower portion of joint capsuleattaches ________________ to _______

Answer 1

mandibular condyle to disc

Question 2

Upper portion joint capsule attaches ______ to _____________

Answer 2

disc to temporal bone

Question 3

Where is the joint capsule thin and thick?

Answer 3

• thin posteriorly and anteriorly
• thickened/supported laterally/medially by collateral ligaments

Question 4

What is the thickest and thinnest part of the disc?

Answer 4

• anterior is thickets
• thinnest in middle

Question 5

What is the disc attached to? (3 total, anterior and posterior)

Answer 5

• joint capsule
• posterior - retrodiscal lamina
• anterior - lateral pterygoid and anterior articular capsule

Question 6

action of lateral pterygoid

Answer 6

Pulls disc forward (concentrically) during opening and gradually pulls it (eccentrically) during closure

Question 7

What is the function of the disc?

Answer 7

Separates joint cavity into two functional components
- Upper joint is a plane gliding joint for translation of mandible condyles
- Lower joint is a hinge joint that permits rotation of condyles

Question 8

What is the retrodiscal lamina? Function?

Answer 8

Fatty layer that is innervated well to help with proprioception
- stabilize disc
prevents excessive translation of the disc over the condyle

Question 9

What counters the lateral pterygoid pull?

Answer 9

tempromandibular ligament
- helps prevent posterior dislocation of the joint
- prevents medial slippage of disc

Question 10

What are the muscles of mastication?

Answer 10

• temporalis
• masseter
• medial pterygoid
• lateral pterygoid

Question 11

What are the suprahyoid muscles?

Answer 11

• stylohyoid
• digastric
• geniohyoid
• mylohyoid

Question 12

What are the infrahyoid muscles?

Answer 12

• thyrohyoid
• sternothyroid
• sternohyoid
• omohyoid

Question 13

action of the temporalis

Answer 13

elevate mandible

Question 14

action of the masseter

Answer 14

elevation and protrusion of mandible

Question 15

action of the medial pterygoid

Answer 15

elevate and protrude mandible

Question 16

action of the lateral pterygoid

Answer 16

• protude and depress mandible
• lateral deviation of mandible (unilaterally)

Question 17

What muscles depress the hyoid? What are their innervations?

Answer 17

infrahyoid muscles
- innervated by branches of C1-C3

Question 18

What muscles elevate the hyoid?

Answer 18

suprahyoid muscles

Question 19

action of the diagastric

Answer 19

depresses mandible against resistance and elevates hyoid

Question 20

opening ROM

Answer 20

35-50 mm
- 3 fingers

Question 21

lateral deviation ROM

Answer 21

10-15 mm

Question 22

protrusion ROM

Answer 22

3-6 mm

Question 23

retrusion ROM

Answer 23

3-4 mm

Question 24

resting and closed packed position of TMJ

Answer 24

resting - slight opening (tongue resting on roof of mouth)

closed-packed - fully closed

Question 25

MOI of masticatory muscle disorders

Answer 25

- strain/direct trauma - overuse injury (grinding, nail binding, etc) - central mediated pain

Question 26

physical exam findings of masticatory muscle disorders

Answer 26

- tenderness and increased turger of muscles - limited ROM - painful at end range - pain with resistance testing - pain w/ tongue depressor biting on ipsilateral side

Question 27

general physical exam findings of joint dysfunction

Answer 27

- perauricular (ear) pain commonly primary complaint - painful palpation of joint line - pain w/ compressive load joint testing

Question 28

disc dysfunction with reduction physical exam findings

Answer 28

- audible clincking and/or palpable clicking - ROM intact

Question 29

disc dysfunction without reduction physical exam findings

Answer 29

- report catching sensation with opening/closing - limitations in opening ROM

Question 30

pathomechains of c-type curve

Answer 30

- anteior displacement of a disc (ipsilaterally) w/o reduction OR unilateral muscle hypomobility - hypomobility of ipsilateral joint

Question 31

pathomechains of s-type curve

Answer 31

- muscular imbalance or medial displacement - condyle "walks around the disc"

Question 32

Biomechanics of early and late deviation

Answer 32

early - spasm late - capsulitis/tight capsule

Question 33

What is happening when there is a click during opening?

Answer 33

reduction of the disc as the mandibular condyle passes over the posterior border

Question 34

What is happening when there is a reciprocal click during opening and closing?

Answer 34

Condyle slips posteriorly over (anteriorly) displaced disc - clicking occurs with closing

Question 35

T/F: DDWOR do not see a ROM limitation

Answer 35

false - usually see a potential ROM limitation

Question 36

What curve is expected with DDWOR?

Answer 36

C curve

Question 37

What may be the issue if the patient reports crepitus?

Answer 37

joint dysfunctions