TMJ

Question 1

TMJ ROM

Answer 1

Full opening: 40-60mm
Lateral deviation: 8-12mm
Protrusion: 3-6mm

Question 2

To which surface of the joint is the disc more attached to?

Answer 2

Convex surface of the mandibular condyle

Question 3

What are the disc’s medial/lateral attachments?

Answer 3

Medial collateral ligaments and lateral collateral ligaments connect the disc to the medial and lateral poles of the condyle

Question 4

What are the disc’s posterior attachments?

Answer 4

The disc is continuous with the posterior attachment

Question 5

What are the disc’s anterior attachments?

Answer 5

The disc is attached to the joint capsule and the superior lateral pterygoid

Question 6

What type of joint is the TMJ and what motions does it do?

Answer 6

Modified hinge; Anterior gliding and hinge-like rotation

Question 7

What are the two phases of mouth opening?

Answer 7

Phase 1: First 10-15mm, rotation occurs in this phase.

Phase 2: After 15mm, the head of the mandible and the articular disc glide anteriorly.

Question 8

What is functional opening?

Answer 8

About 40mm

Question 9

What muscles contribute to mouth closing?

Answer 9

Temporalis
Masseter
Medial pterygoid

Question 10

What muscles contribute to protrusion?

Answer 10

Medial pterygoid

Lateral pterygoid

Question 11

What muscles contribute to retrusion?

Answer 11

Posterior fibers of temporalis

Question 12

What muscles contribute to mouth opening?

Answer 12

Lateral ptyergoid
Digastric
Stylohyoid

However, gravity does most of the work here.

Question 13

TMJ joint noises and what they might mean

Answer 13

Clicking: disc dysfunction and/or hyper mobility
Grinding: arthritis

Question 14

TMJ OPP

Answer 14

Relaxed opening

Question 15

TMJ CPP

Answer 15

Fully opened or fully closed