TMJ and masseteric muscles

Question 1

Identify these muscles

Action? Innervation?

Answer 1

1. Masseter (deep head)
2. Masseter (superficial head)
   - > action - elevates mandible
   - > nerve - Masseteric n. from mandibular division of trigeminal n.

Question 2

Identify

Action? Nerve?

Answer 2

1. Temporalis
   A - Elevates mandible; Retrudes mandible (posterior fibers)
   N - Anterior and posterior deep temporal nn. from mandibular division of trigeminal n.

Question 3

What is the Main postural muscle that maintains mandible in rest position?

Answer 3

Temporalis

Question 4

Identify. Actions? Innervation?

Answer 4

1. Superior head of the lateral pterygoid m.
2. Inferior head of the lateral pterygoid m.

Actions:
Depresses mandible
Protrudes mandible
Lateral excursion of mandible

Nerve: Lateral pterygoid branches (for each head) of mandibular division of trigeminal

Question 5

Identify. Actions? Innervation?

Answer 5

1. Deep head of the medial pterygoid m.
2. Superficial head of the medial pterygoid m.

Actions:
Elevates mandible
Protrudes mandible
Lateral excursion of mandible

Nerve: Lateral pterygoid branches (for each head) of mandibular division of trigeminal

Question 6

What is the deepest muscle of mastication?

Answer 6

medial pterygoid m.

Question 7

Where do the arteries of muscles of mastication arise from?

Answer 7

2nd part of the maxillary a. (pterygoid part).

Question 8

Arteries of the Muscles of Mastication

Answer 8

1. Masseteric a.
2. Posterior deep temporal a.
3. Anterior deep temporal a.
4. Lateral pterygoid a.
5. Buccal a.
6. Medial pterygoid a.
7. External carotid a.
8. Maxillary a.

Question 9

The nerves that supply the muscles of mastication arise from the ___

Answer 9

mandibular division of the trigeminal n

Question 10

Nerves of the Muscles of Mastication

Identify 1 - 4

Answer 10

1. Chorda tympani n.
2. Auriculotemporal n.
3. Mandibular n.
4. Posterior deep temporal n.

Question 11

Nerves of the Muscles of Mastication

Identify 5 - 8

Answer 11

5. Anterior deep temporal n.
6. Masseteric n. (cut)
7. Lateral pterygoid n.
8. Buccal n.

Question 12

the mandibular division of the trigeminal n.
-> After passing through the foramen (1)___ within the (2)___ fossa, the mandibular division divides into (3)___ and (4)___ divisions.

Answer 12

1 - ovale
2 - infratemporal
3 - anterior
4 - posterior

Question 13

Compartments of the Temporomandibular Joint

Identify 6 - 8

Answer 13

6. Retrodiscal pad
7. Superior lamina
8. Articular disc

Question 14

Joint type of TMJ

Answer 14

a ginglymoarthrodial joint because it has hinge and sliding movements

Question 15

Veins of the Temporomandibular Joint

Answer 15

1. Pterygoid plexus
2. Maxillary v.
3. External jugular v.
4. Posterior retromandibular v.
5. Retromandibular v.
6. Posterior auricular v.
7. Transverse facial v.
8. Superficial temporal v.

Question 16

Course of superficial temporal vein

Answer 16

Receives some branches from TMJ

Joins maxillary v. to form retromandibular v.

Question 17

Course of maxillary vein

Answer 17

Receives some branches from TMJ

Joins superficial temporal v. to form retromandibular v.

Question 18

Sensory Nerves of the Temporomandibular Joint

Answer 18

1. Otic ganglion
2. Masseteric n.
3. Auriculotemporal n.
4. Inferior alveolar n.
5. Lingual n.
6. Nerve to the mylohyoid

Question 19

Course of Auriculotemporal nerve

Answer 19

From posterior division of mandibular division of trigeminal n.

• > Supplies sensory branches all along capsule
• > carries autonomic function to parotid gland

Question 20

What is the condition being depicted in the last image?

Answer 20

Dislocation of the Mandible

-> Mandibular dislocation occurs when the condyle moves anterior to the articular eminence.

Question 21

Source of Masseteric nerve

Answer 21

Anterior division of mandibular division of trigeminal n.

Question 22

Source of Posterior deep temporal nerve

Answer 22

Anterior division of mandibular division of trigeminal n.