TMJ unit 15 oral anatomy

What is the tmj an articulation between

Condylar process of the mandible and squamous portion of the temporal bone

What part of the temporal bone does the condylar process articulate with

Glenoid fossa

Articular eminence

What is the glenoid fossa aka

Mandibular fossa

What kind of joint is the TMJ

Ginglymoartrodial joint

What actions does the TMJ do

Hinge and gliding action

What is the type of the 2 joints that the TMJ is comprised of

Synovial / diarthrosis joints

What 2 joints is the TMJ divided into by the TMJ disc/meniscus

Superior disco-temporal joint

Inferior disco-mandibular joint

What are the 2 spaces in the TMJ divided by

TMJ disc / meniscus

What are the 2 movements of the condyle

Rotation and translation

What are the 4 structural components of the TMJ

• squamous portion of temporal bone does

• Articular disc

• Condylar process of mandible

• Ligaments

Is the squamous portion of the temporal bone avascular?

And what part

Yes

Articular surface

What is the avascular articular surface of the squamous portion composed of

Fibrous ocnntective tissue

Fibrocartilage

What type of cartilage does the articular surface of the squamous portion is NOT composed of

Hyaline cartilage

Where are the load bearing areas of the squamous portion of the temporal boen

Lateral aspect of it

What specific parts of the lateral aspect of the squamous portion are load-bearing

Condyle and articular disc

Is the fibrous CT thicker and denser in the load bearing areas?

Yes

What is the anterior limit of the squamous portion

Articular eminence

What is the intermediate limit of the squamous protion

Glenoid fossa

What forms the posterior area of the squamous portion

Tympanic plate tapering to the postglenoid tubercle

Which of these are bigger: superior discotemporal and inferior discomandibular

Superior discotemporal

What type of joint does the articular disc form

Bicameral

What is a bicameral joint

A joint that has 2 chambers

What type of movement does the superior discotemporal joint provide

Translational movement

What type of movement does the inferior discomandibular joint provide

Rotational movement

What characteristics does the articular disc have in the central part

Avascular and aneural

(Where it is very thin)

Where in the articular disc is it vascular and innervated

In the periphery

What aspect of the articular disc is mainly load bearing

Lateral aspect

Where is the articular disc fused to the capsule

Medially and laterally

How many sections can the articular disc be divided into

4

What is the natural position of the mouth

Closed but not occluding

What are the 4 sections of the articular disc

• anteiror ligament

• Intermediate zone

• Posterior ligament

• Bilaminar zone

what is the anterior ligament anterior to

Condyle

Is the anterior ligament in the articular disc thick

Yes

Is the intermediate zone in the articular disc seciton thick

No

Where is the intermediate zone in the articular dsic found

Along the articular eminence

Is the posteriori ligament thick

Yes

Where is the posterior ligament Of the articular disc found

Superior area of the disc

Where is the bilaminar zone of the articular disc found

Posterior to the articular disc

Is the bilaminar zone of the articular disc highly distortable or rigid

Highly distortable

What 3 things is the bilaminar zone of the articular dsic composed of

Supeiror lamina

Retrodiscal pad

Infeiror lamina

What does the superior lamina of the bilaminar zone of the articular disc do

Anchors posterior ligament (of articular disc) to capsule (at postglenoid tubercle)

What is the retrodiscal pad of the bilaminar zone of the articular disc

Highly vascularised and innervated portion

What does the infeiror lamina of the bilaminar zone of the articular disc do

Anchor the (inferior aspect of the posterior portion of the) articular disc to the condyle

How many types of TMJ disorders

5

What are the 5 types of TMJ disorders

• perforations of articular disc

• Anterior disc displacement

• Mandibular dislocation

• Arthritis

• Ankylosis

Where does the thin articular capsule pass from where

The edge of the glenoid fossa around the articular tubercle

What does the articular capsule attach

The cranial to the pterygoid fovea

Where is the articular capsule toughened

The medial and lateral aspects by the ligaments

What lines the articular capsule

Highly vascular synovial membrane lines it

Does the articular capsule have sensory receptors

Yes