The document outlines the muscles of mastication, detailing four main muscles: temporalis, masseter, lateral pterygoid, and medial pterygoid. Each muscle is described with its origin, insertion, nerve supply, and primary actions, such as elevation and movement of the mandible. Key functions include protrusion, retraction, and side-to-side movements that facilitate chewing.

1. Muscles of mastication
By:
Dr: Omar Abdelsalam

2. Muscles of mastication
1
Temporalis
2
Masseter
4
Medial
pterygoid
3
Lateral
pterygoid

3. 1
Temporalis
Muscle
Origin
Insertion
Nerve Supply
Action
• Temporal fossa.
• Temporal fascia covers muscle.
• Coronoid process of mandible.
• Two branches of anterior
division of mandibular
nerve .
• Elevation of mandible by
anterior vertical muscle
• Retraction of mandible by
posterior horizontal muscle
fibers .

4. 2
Masseter
muscle
Origin
Insertion
Nerve Supply
Action
• Zygomatic arch
• Lower border of inner surface
of zygomatic arch.
• Outer surface of ramus of
mandible (Lateral) .
• Anterior division of
mandibular nerve .
• Elevation of mandible .
• Protraction of mandible by
its superficial oblique fibers.
• Not considered of content of
infratemporal fossa .

5. 3 Lateral
pterygoid
muscle
Origin
Insertion
Nerve Supply
Action
• Upper head of infra-temporal surface of
greater wing of sphenoid .
• Lower head of lateral surface of lateral
pterygoid plate .
• Pterygoid fovea in front of the neck of
mandible .
• Capsule of TMJ .
• Articular disc of TMJ .
• Anterior division
of mandibular nerve
• Protrusion of mandible
• Opening mouth
• Side to side movement with medial pterygoid .

6. 4 Medial
pterygoid
muscle
Origin
Insertion
Nerve Supply
Action
• Superficial head from maxillary
tuberosity.
• Deep head from medial surface of lateral
pterygoid plate.
• Inner surface of the angle
of mandible (Medial
surface).
• Branch from trunk of
mandibular nerve.
• Elevation & Protrusion of mandible .
• Side to side movement with lateral
pterygoid.