Muscles of the TMJ

Question 1

What are the 4 muscles acting on the TMJ

Answer 1

Temporalis
Masseter
Lateral pterygoid
Medial pterygoid

Question 2

Temporalis

PA
DA
N/S
A

Answer 2

• Floor of the temporal fossa - up to the inferior temporal line, deep surface temporal fascia
• Coronoid process of the mandible, anterior ramus
• CN V3 mandibular div, of the trigeminal nerve
• Elevates the mandible (closes jaw), posterior fibres retract the mandible

Question 3

Masseter

PA
DA
N/S
A

Answer 3

• Zygomatic bone and zygomatic arch
• Angle and lateral side of ramus of the mandible
• CN V3 mandibular div, of the trigeminal nerve
• Elevates the mandible, assists in protrusion

Question 4

Lateral Pterygoid

PA
DA
N/S
A

Answer 4

-Greater wing of the sphenoid: lateral surface of the lateral pterygoid plate
- Neck of the mandible and articular disc
- CN V3 mandibular div, of the trigeminal nerve
-Bilaterally: protrudes the mandible, depresses chin
Unilaterally: move jaw to the contralateral side

Question 5

Medial pterygoid

PA
DA
N/S
A

Answer 5

-Medial surface of the lateral pterygoid plate, palatine & maxillary bone
-Medial surface of the mandibular ramus
- CN V3 mandibular div, of the trigeminal nerve
- Elevates mandible and assist in protrusion
Unilaterally produces a grinding movement.