7- TMJ

Question 1

_______% of the general population of at least one sign of TMD…. but only ____% will seek treatment

Answer 1

60-70%, 5%

Question 2

Females seek care ____x more than males

Answer 2

4x

Question 3

What type of joint is the TMJ? What does it consist of?

Answer 3

modified ovoid bicondylar joint

temporal bone, biconcave intra-articular disk, head of mandible

Question 4

What is the origin and insertion of the temporalis?

Answer 4

temporal floor –> coronoid process and mandible

Question 5

What is the temporalis innervated by?

Answer 5

trigeminal

Question 6

What does the temporalis do?

Answer 6

mouth closing and side to side teeth drinding

Question 7

What is the origin and insertion of the Masseter?

Answer 7

Zygomatic arch –> mandible

Question 8

What innervates the masseter?

Answer 8

trigeminal

Question 9

What does the masseter do?

Answer 9

elevates mandible

Question 10

What is the origin and insertion of the medial pterygoid?

Answer 10

ramus of mandible –> angle of mandible

Question 11

What innervates the medial pterygoid?

Answer 11

trigeminal

Question 12

What does the medial pterygoid do?

Answer 12

assist mouth closing and deviating to the opposite side

Question 13

What is the origin and insertion of the lateral pterygoid?

Answer 13

sphenoid –> pterygoid plate –> capsule and neck of mandible

Question 14

What innervates the lateral pterygoid?

Answer 14

trigeminal

Question 15

What does the lateral pterygoid do?

Answer 15

anteriorly rotates the disk on the condyle during closing, jaw protrusion, opening, and deviation to the opposite side

Question 16

explain the arthrokinematics of protrustion and retrusion?

Answer 16

planar glides

Question 17

What happens during mouth opening?

Answer 17

• condyles begin to rotate anteriorly and translate inferiorly and laterally during the first 25 degrees
• during the last 15 degrees collateral ligaments tighten and rotation ceases (translation occurs as well)

Question 18

Decreased mouth opening due to ______ stiffness leads to over-recruitment of _______ which leads to cervicogenic headaches and compressive TMJ pain

Answer 18

masseter

uppercervical extensors

Question 19

What is abnormal when viewing opening from the lateral side?

Answer 19

cervical extension, protrusion

Question 20

What is abnormal when viewing opening from the front?

Answer 20

side deviations or lack of opening