Temperomandibular Joint

Question 1

Classification of temporomandibular joint(TMJ)

Answer 1

Synovial joint of condylar variety

Question 2

Number of articulating surfaces

Answer 2

3

Question 3

Articulating surfaces are

Answer 3

I. The condyle of the mandible
II. Mandibular fossa
III. The articular tubercle (the squamous part of the temporal bone)

Question 4

The mandible articulates to ___________

Answer 4

The cranium with a mandibular fossa on either side

Question 5

TMJ are ____________

Answer 5

Bilateral components of craniomandibular articulation

Question 6

Capsule

Answer 6

A dense, irregular collagenous connective tissue that encloses the articulating surfaces

Question 7

Attachment of capsule

Answer 7

Attached:
1. Above to the articular tubercle and the margins of the mandibular fossa
2. Below to the neck of the mandible

Question 8

TMJ is formed by ______________

Answer 8

the articulation of the mandible and the temporal bone of the cranium

Question 9

Number of ligaments

Answer 9

3

Question 10

Lateral ligaments

Answer 10

Runs down and backwards from the tubercle to attach to the lateral aspect of the mandibular neck

Question 11

The ligament limits movement of the ___________ in ______________

Answer 11

1. Mandible.
2. Posterior direction

Question 12

Sphenomandibular ligament

Answer 12

It extends from the spine of the sphenoid bone to the lingula of the mandibular foramen

Question 13

Sphenomandibular ligament acts as ______

Answer 13

Passive support for the mandible
>helping to limit excessive movement

Question 14

Stylomandibular ligament

Answer 14

Runs from the apex of styloid process to the angle of the mandible

Question 15

Articular disc/meniscus

Answer 15

It’s composed of dense fibrocartilagenous tissue. It divides the joint into 2 distinct compartments

Question 16

Upper surface of the disc

Answer 16

It’s concavoconvex from ant. to the post. to fit the shape of the articular tubercle and mandibular fossa

Question 17

Lower surface of the disc

Answer 17

It is concave to fit the head of the mandible

Question 18

Arterial supply to the TMJ

Answer 18

Branches of the external carotid arteries
A. Superficial temporal artery
B. Maxillary artery
C. Ascending pharyngeal artery

Question 19

Innervation of the TMJ

Answer 19

It’s innervated by branches of the mandibular nerve, the third division of the trigeminal nerve (CN V). The nerves:
A. Auriculotemporal nerve
B. Masseteric nerve
C. Deep temporal nerve

Question 20

Movements of the temporomandibular joint

Answer 20

1. Protrusion
2. Retraction
3. Elevation
4. Depression

Question 21

Protrusion

Answer 21

Moving the mandible forward. The lateral pterygoid muscle is mainly responsible for the movement and is assisted by the medial pterygoid muscle

Question 22

Retraction/Retrusion

Answer 22

Moving the mandible backward. Movement is facilitated by the posterior fibers of the temporalis muscle, as well as the digastric and geniohyoid muscles

Question 23

Elevation (closing the mouth)

Answer 23

This movement involves raising the mandible to close the mouth. The main muscles involved are the masseter, temporalis, and medial pterygoid muscles.

Question 24

Depression (opening the mouth)

Answer 24

This action involves lowering the mandible to open the mouth and is primarily performed by the digastric, mylohyoid, and geniohyoid muscles, with assistance from gravity.

Question 25

Lateral movement (side to side)

Answer 25

This involves alternating contraction of the lateral pterygoid muscles on one side and the medial pterygoid muscles on the opposite side.

Question 26

Movements of the TMJ is produced by ______

Answer 26

Muscles of mastication and hyoid muscles