TMJ

Question 1

Temporalis

Answer 1

O: Floor of temporal fossa
I: medial surface of coronoid process
nn: mandibular branch of Trigeminal nerve
Fx: Elevation, closing, retrussion

Question 2

Masseter

Answer 2

O: Zygomatic arch
I: Ramus of mandible
nn: mandibular branch of Trigeminal nerve
Fx: elevation, protrusion, closing

Question 3

Medial Pterygoid

Answer 3

O: Medial surface of lateral pterygoid plate
I: Medial surface of ramus
nn: mandibular branch of Trigeminal nerve
Fx: Mandibular, elevation, protrusion

Question 4

Lateral Pterygoid

Answer 4

O: Greater wing of sphenoid and lateral surface of pterygoid plate
I: neck of mandible, mandibular
nn: mandibular branch of Trigeminal nerve
Fx: Protrusion, side to side movement , lateral deviation(opposite direction), opening of the mouth

Question 5

are the articular surface of the mandibular condyles concave or convex?

Answer 5

convex

Question 6

is the articular eminence of the temporal bone concave or convex?

Answer 6

concave

Question 7

Does trauma to one TMJ always involve the contralateral TMJ joint?

Answer 7

yes

Question 8

what type of joint is TMJ?

Answer 8

Complex synovial joint (only looks like a hinge joint)

Question 9

what types of movements occur at the TMJ joint?

Answer 9

gliding, angling, rotating

Question 10

what does the bilaminar zone attach to?

Answer 10

to the posterior disc.
assists the head of the condyle in moving forward.
The disc is attached to the lateral pterygoid muscle anteriorly.

Question 11

what are the motions allowed at the TMJ?

Answer 11

allows the jaw to open, close, protrude, retract, and deviate laterally.

Question 12

What is the TMJ used for?

Answer 12

chewing and speaking

Question 13

how wide does a normal TMJ typically open?

Answer 13

Normal opening 35-40mm

2 to 3 knuckles

Question 14

Name the four muscles of mastication that move the mandible

Answer 14

Masseter
Temporalis
Medial Pterygoid
Lateral Pterygoid

Question 15

Name the first motion of TMJ biomechanics

Answer 15

First 20mm of motion is rotation. The mandible and meniscus move anteriorly together beneath the articular eminence while opening or closing.

Question 16

Name the second motion of TMJ biomechanics

Answer 16

Second motion is translation, which slides the jaw further forward or from side to side.

Question 17

what % of the population is affected by TMJ symptoms?

Answer 17

Affects more than 25% of the population

Question 18

does TMJ usually occur in women or in men?

Answer 18

90% of people seeking treatment are women