Temperomandibular joint

Question 1

What type of joint is the TMJ joint

Answer 1

Fibrocartilage ginglymoarthrosis joint ( hinge/sliding joint)

Question 2

What are the boney structures of the TMJ joint

Answer 2

Temporal bone- articular eminence
-articular fossa
- postglenoid process
Mandible - condyle

Question 3

where is the TMJ situated

Answer 3

Inferior to the zygomatic process, 1-2 cm anterior to the tragus of the ear

Question 4

What is the TMJ capsule and its attachments

Answer 4

A fibrous capsule - attaches from articular eminence and fossa of the temporal bone and wraps around mandible condyle and neck

Question 5

what lines the TMJ capsule

Answer 5

Synovial membrane

Question 6

What’s the job of the TMJ capsule

Answer 6

To hold the joint together
Makes synovial fluid to lubricate the joint
Creates an airtight seal

Question 7

what is the articular disc of the TMJ joint

Answer 7

A fibrous disc that divided the joint into 2 cavities - superior and inferior

Question 8

where does the TMJ disc attach

Answer 8

Into the joint capsule

Question 9

what is the articular discs job in the TMJ

Answer 9

a pad to decrease /spread out compression forces
allow movement of the mandible

Question 10

Name the ligaments of the TMJ joint

Answer 10

Temperomandibular ( lateral) ligament **main
Stylomandibular ligament
Sphenomandibular ligament

Question 11

Name the main ligament of the TMJ joint

Answer 11

Temperomandibular (lateral) ligament

Question 12

Name the attachments of the main ligament of the TMJ joint

Answer 12

Temperomandibular ligament
inferior part zygomatic process ->lateral neck /condyle mandible

Question 13

Name movements of the TMJ joint and synovial cavity involved

Answer 13

Sliding - (protraction/retraction)- Upper synovial cavity ( between articular eminence and disc)

Hinge ( depression/elevation jaw)- lower synovial cavity (- disc and condyle )

Question 14

what movement does the temperomandibular ligament stop

Answer 14

Excess retraction( other 2 ligaments stop protrusion)

Question 15

What group muscles depresses mandible at TMJ

Answer 15

Suprahyoids - myelohyoid, geniohyoid,digastric,

Question 16

What muscle(s) elevate mandible

Answer 16

Muscles mastication - masseter ,temporalis, pterygoid - medial (NOT LATERAL)

Question 17

What muscle protrudes mandible

Answer 17

Lateral pterygoid

Question 18

What muscle retracts mandible

Answer 18

Temporalis

Question 19

What is the interocclusal clearance

Answer 19

2-4mm space between teeth that we rest our mouth open at ( neutral rest position)

Question 20

what is occlusion

Answer 20

when maxillary and mandibular teeth touching

Question 21

What is centric occlusion mouth

Answer 21

position of LOWER jaw when all teeth fully occluded

Question 22

What is centric relationship

Answer 22

CONDYLE positioned approximately in centre of articular fossa

Question 23

3 things affecting a patients occlusion

Answer 23

TMJ components
teeth coming together position
neuromuscular factors

Question 24

name a TMJ disorder

Answer 24

dislocation jaw - usually by trauma but then can get reoccurent from yawning etc
Condyle no longer sitting in the articular fossa
Pain and unable close mouth on the affected side