12) TMJ and Infratemporal Fossa

Question 1

What are the articulations in the temporomandibular joint?

Answer 1

Condyle of mandible
Mandibular fossa
Articular tubercle (temporal bone)

Question 2

What separates the articular surfaces?

Answer 2

Articular disk

Question 3

What covers the articular surfaces?

Answer 3

Fibrocartilage

Question 4

What are the 3 extra-capsular ligaments of the TMJ?

Answer 4

Lateral (temporomandibular)
Stylomandibular
Sphenomandibular

Question 5

What muscles cause elevation of the TMJ?

Answer 5

Temporal, masseter and medial pterygoid

Question 6

What muscles cause depression of the TMJ?

Answer 6

Lateral pterygoid and supra/infrahyoid muscles (mainly gravity)

Question 7

What muscle causes protrusion of the TMJ?

Answer 7

Lateral pterygoid

Question 8

What muscle causes retrusion of the TMJ?

Answer 8

Temporal

Question 9

What muscles cause lateral movements of the TMJ?

Answer 9

Temporal on same side, pterygoids on opposite side and masseter

Question 10

What is the nerve supply to the muscles of mastication?

Answer 10

Mandibular branch of trigeminal

Question 11

Describe a TMJ dislocation:

Answer 11

Anterior causing head of mandible to move out of mandibular fossa (anterior to articular tubercle)

Question 12

What can be damaged in a TMJ dislocation?

Answer 12

Facial and auriculotemporal nerves

Question 13

What can cause a TMJ dislocation?

Answer 13

Blow to side of face, yawning or taking a large bite

Question 14

What other TMJ disorders are there?

Answer 14

Bruxism (teeth grinding)
Osteoarthritis
Inter-articular disk derangement

Question 15

How do TMJ disorders usually present?

Answer 15

Pain in region of auriculotemporal nerve (V3)

Question 16

What are the muscular contents of the infratemporal fossa?

Answer 16

Temporal, lateral and medial pterygoid muscles

Question 17

What are the vascular contents of the infratemporal fossa?

Answer 17

Maxillary artery and vein

Pterygoid venous plexus

Question 18

What are the nervous contents of the infratemporal fossa?

Answer 18

Mandibular nerve: inferior alveolar, lingual, buccal nerves
Chorda tympani
Otic ganglion

Question 19

What pathology can occur in the infratemporal fossa?

Answer 19

Risk of cavernous sinus thrombosis due to communication with pterygoid plexus
Extradural haematoma
Isolated infections

Question 20

What is the clinical relevance of the infratemporal fossa?

Answer 20

Used as site for mandibular nerve blocks

Question 21

Describe the location of the infratemporal fossa:

Answer 21

Deep and inferior to zygomatic arch and deep to ramus of mandible