Muscles of mastication

Question 1

primary muscles of mastication

Answer 1

Primary Muscles of Mastication

Temporalis
Proximal: Temporal Fossa
Distal:Coronoid Process of mandible
Position:Anterior to TMJ (MA)

• Ant fibres vertical
  
  • Post fibres horizontal
    Action:Unilateral: retrusion and elevation of mandible at TMJ Bilateral: Retrusion/ elevation and ispsilateral deviation of mandible at TMJ

Masseter
Proximal:Zygomatic Arch
Distal:Lateral surface of ramus of mandible

Anterior to TMJ
Bilateral/Unilateral : Elevation and protrusion of mandible at TMJ

Medial Pterygoid
Proximal:Medial surface of lateral pterygoid plate
Distal: Medial surface of ramus of mandible
Bilateral: Elevates/protrusion of mandible at TMJ
Unilateral: contralateral lateral deviation of mandible at TMJ

Lateral Pterygoid
Proximal:Lateral surface of lateral pterygoid plate
Distal: neck of mandible, joint capsule / articular disk of TMJ

Trigeminal Nerve (V)
Bilateral: Protrusion/ some deviation of mandible at TMJ

Unilateral: Contralateral lateral deviation of mandible at TMJ

All muscles of mastication are innervated by the madibular branch of the trigeminal nerve, this nerves travels through foramen ovale- in the floor of the middle cranial fossa to emerge into the infratemporal fossa.