TMJ

Question 1

Where do the nerves and vessels to masseter pass?

Answer 1

Superior border of mandible - between condylar and coronoid process

Question 2

What is the mylohyoid line and why is relevant clinically and in denture construction?

Answer 2

Mylohyoid line is an anatomical landmark on the medial side of the body of the mandible.
Infections of lower teeth that develop LARGE abscess may cause infections to spread below this line - INTO FOM AND SUBMANDIBULAR REGION - LUDWIG’S ANGINA

Dentures should not extend past this line as the mylohyoid muscle is here and denture would be displaced when chewing or speaking due to contraction of mylohyoid muscle

Question 3

Why is the TMJ an atypical joint?

Answer 3

Modified hinge synovial joint - allows for movement - has synovial fluid.
Covered in FIBROCARTILAGE.

Question 4

What is the articular disc in the TMJ?

Answer 4

Dense CT that separates upper and lower cavities

Question 5

What are the 2 extrinsic ligaments of the TMJ?

Answer 5

Sphenomandibular - runs from spine of sphenoid to lingula. PRIMARY PASSIVE SUPPORT OF MANDIBLE (MOM also help bear mandible’s weight)

Stylomandibular - runs from styloid process to angle of mandible - thickening of capsule in parotid.

Question 6

What is the intrinsic ligament of the TMJ?

Answer 6

Lateral ligament of TM - THICKENED PART OF JOINT CAPSULE.
Laterally strengthens the joint. Helps prevent POSTERIOR DISLOCATION.