TMJ

Question 1

what type of joint is the TMJ ?

Answer 1

synovial joint ( condylar variety )

Question 2

what bones are associated with the TMJ ?

Answer 2

mandibular fossa of the temporal bone and head condyle of the mandible

Question 3

what are the articular surfaces of the TMJ covered by ?

Answer 3

articular cartilages

Question 4

what does the articular disk do ?

Answer 4

divides the joint cavity into (upper) menisco-temporal compartment

and (lower) monisco-mandibular compartment

Question 5

where does the fibrous capsule attach ?

Answer 5

it envelops the joint and gains its attachment to the margin of the auricular surfaces ( margins of mandibular fossa and neck of mandible below )

Question 6

what lines the inner aspect of the capsule ?

Answer 6

synovial membrane ( except for auricular cartilages and auricular disc )

Question 7

what ligaments are associated with TMJ ?

Answer 7

1.) Fibrous capsule

2. ) Temporo-mandibular ligament
   - accessory ligaments
3. ) sphenomandibular ligament

4.)stylomandubular ligament

Question 8

describe the lateral temporo-mandibular ligament .

Answer 8

• it blends with the lateral part of the fibrous capsule

- it extends from the root of the zygoma to the lateral surface of the neck of mandible

Question 9

what are the accessory ligaments ?

Answer 9

Sphenomandibular : derived from Meckel’s cartilage of the first branchial arch

it extends from the spine of the sphenoid bone to the lingula (medial surface of ramus ) of mandibular bone

Stylomandibular ligament : is the thickening of deep cervical fascia

extends from styloid process above to angle of mandible below

Question 10

what is the articular disc?

Answer 10

it is an oval plate of fibrocartilage tthat divides the joint cavity into 2 compartments .

morphologically it represents the degenerated primitave insertion of lateral pterygoid muscle

it is composed of an anterior extension , anterior thick band , intermidiate zone , posterior thick band , and bilamellar region

Question 11

what is lateral in terms of the TMJ ?

Answer 11

skin , fascia , parotid gland , temporal branches of facial nerve

Question 12

what is medial in terms of the TMJ ?

Answer 12

Lateral pterygoid , auriculo-temporal nerve with middle meningeal artery , sphenomandibular ligament

Question 13

what is anterior and posterior to the TMJ ?

Answer 13

lateral pterygoid , temporalis , massetric nerves and vessels

posterior : parotid gland , superficial temporal vessels , auriculotemporal nerve and external acoustic meatus

Question 14

blood supply of TMJ :

Answer 14

branches of superficial temporal and maxillary arteries

Question 15

nerves supply :

Answer 15

auriculo-temporal nerve

massetric nerve