TMJ Anatomy

Question 1

TMJ—> unique features

Answer 1

Bilateral diarthrosis—> function together
(Protrusive mov lateral extrusion opening closing move)
Ginglymoarthrodial—> hinge and sliding movement
Articulating surfaces—> fibrocartilage dense
Unique Joint—> rigid endpoint of closure teeth oclussal contact
Development late —> 7 weeks in utero

Question 2

Articular disc

Answer 2

Fibrocartilage devoid blood vassels nerve fibers
Type 1 collagen
Bicóncave shape—> thinnest center
Thickest edges
Ant thicker
Post thickets overall
Medial thicker than laterally

Disc separate into 2 compartments
Upper—> translational movements protrusion and retrusion
Lower—> below disc —> rotational movements closing and opening

Question 3

Rerrodiscal tissue (post attachment)

Answer 3

Behind articular disc

Superior retrodiscal lamina—> elastic fibers
Prevents from dislocating anteriorly
Inferior —> collagen fibers
Prevents from exceso rotating over condyle
Intermediate —> loose areolar connective tissue

Question 4

Superior retrodiscal lamina

Answer 4

Attaches to articular disc
Attaches to the tympanic plate temporal nerve
Function—> to counter the forward pull of the sup belly of lateral pterygoid muscle on the articular disc
Lateral pterygoid going to put pressure on the articular disc to move forward as the Md is open
So the condyle and the disc move forward together

Question 5

Inferior retrodiscal lamina

Answer 5

Attaches the articular disc to post surface of condylar neck

Question 6

Intermediate retrodiscal lamina

Answer 6

During jaw opening as the condyle move forward