Head - Muscles of mastication

Question 1

Commonalities between muscles of mastication

Answer 1

Assist with mastication
Insertion on mandible
Therefore action is on the mandible
Superficial muscles action –> elevation & retraction
Innervation by V3= mandibular branch of trigeminal nerve

Question 2

Superficial muscles

Answer 2

Temporalis
Masseter
Elevate & retract

Question 3

Deep muscles

Answer 3

Lateral pterygoid
Medial pterygoid
Lateral movement

Question 4

Temporalis

Answer 4

Superficial muscle
Origin: temporal fossa of parietal bone
Insertion: coronoid process & anterior ramus of mandible
Action: elevation (ant and mid fibers) & retraction (post fibers)

Question 5

Masseter

Answer 5

Superficial muscle
Origin: zygomatic bone, zygomatic arch
Insertion: Angle & lateral ramus of mandible
Action: elevation & retraction

Question 6

Medial pterygoid

Answer 6

Deep muscle
Origin: deep head- lateral pterygoid process of sphenoid & superficial head- tuberosity of maxilla
Insertion: Angle & medial ramus of mandible
Action: elevation & lateral movement

Question 7

Lateral pterygoid

Answer 7

Deep muscle
Origin: upper head- infratemporal fossa on greater wing of sphenoid & lower head- lateral pterygoid plate of sphenoid
Insertion: temperomandibular joint capsule
Action: protrusion & lateral movement