Mastication Muscles

Question 1

Buccinator

Answer 1

Origin: Alveolar Process of Maxilla and Mandible
Insertion: Fibers of Orbicularis Oris
Action: Compress Cheeks

Note: Not a muscle of Mastication but keeps food bolus against teeth.

Question 2

Lateral Pterygoid

Answer 2

Two heads: Superior and Inferior

Origin:
Superior: Greater wing of Sphenoid (Lateral surface)
Inferior: Lateral Pterygoid plate (Lateral surface)

Insertion:
Superior: Aticular disc and capsule of TMJ
Inferior: Ramus of mandible, condylar process

Action:
Protrude Mandible
Depress Mandible
Lateral Movement of Mandible

Question 3

Medial pterygoid

Answer 3

Two Heads: Superficial and Deep

Origin:
Superficial: Maxillary Tuberosity
Deep:
- Laterial Pterygoid plate (mesial)
- Mesial Pterygoid plate (lateral)
- Pterygoid Fossa

Insertion:
Both: Ramus and angle of mandible

Action:

• Elevate Madible
• Protrude Madible
• Unilateral movements

Question 4

Masseter

Answer 4

Two Heads: Superficial and Deep

Origin:
Superficial: Anterior 2/3 of Zygomatic Arch
Deep: Posterior 1/3 of Zygomatic Arch

Insertion:
Superficial: Lateral surface of angle and ramus.
Deep: Lateral surface of ramus and coronoid process

Action:

• adduct mandible
• protrude
• unilateral movements

Question 5

Passing superficial to Masseter

Answer 5

• Parotid Duct
• Transverse facial artery
• Branches of CNVII

Question 6

Temporalis

Answer 6

Origin: Inferior temoral line and Temporal Fossa

Insertion: Coronoid Process and Ramus

Action:
Anterior (vertical Fibers): Elevate Mandible
Middle (oblique fibers): Retrude Mandible
Posterior (horizontal fibers): Retrude and lateral movements of mandible.