Muscles of mastication and their nerve supply.

1. MUSCLES OF
MASTICATION AND
ITS INNERVATIONS
Prepared by: Anish Dhakal (Aryan)
MBBS Student
Patan Academy of Health Sciences

3. MEDIAL PTERYGOID
• Thick, quadrilateral muscle with two
heads of origin
• Origin
• Deep head : medial surface of
lateral pterygoid plate
• Superficial head: maxillary
tuberosity
• Insertion
• Medial surface of ramus & angle of
mandible

4. • Action
• Assists in elevation of mandible
• Protrusion (with association of
lateral pterygoid)
• Chewing movement of mandible
(with alternating activity)
• Vascular supply
• Pterygoid branches of maxillary
artery
• Innervation
• Medial pterygoid branch of
mandibular nerve

5. LATERAL PTERYGOID
• Short, thick muscles, arises by
two heads
• Origin:
• Superior : from infratemporal
surface & infratemporal crest of
greater wing of sphenoid
• Inferior : lateral surface of
lateral pterygoid plate
• Insertion
• Superior : joint capsule &
articular disc of
temporomandibular joint
• Inferior : pterygoid fovea on
anterolateral aspect of neck of
condyloid process of mandible

6. LATERAL PTERYGOID
• Vascular supply
• Pterygoid branches
from maxillary artery
• Innervation
• anterior division of
mandibular nerve
• Action
• Depression of
mandible
• Protrusion of mandible
(combined action with
medial pterygoid)
• Alternating activity,
side to side chewing
movement

7. TEMPORALIS
• Fan shaped
• Origin
• Floor of temporal fossa
below the inferior
temporal line
• Deep surface of
temporal fascia
• Insertion
• Converge & insert into
coronoid process of the
mandible involving its
tip, medial surface &
anterior border of ramus
of mandible

8. TEMPORALIS
• Vascular supply
• Deep temporal branches from the second part of the
maxillary artery
• Innervation
• Deep temporal branches of anterior trunk of the mandibular
nerve
• Action
• Elevates the mandible (closes mouth)
• Posterior fibers help retraction of the mandible
• Side –to-side grinding movements, by muscles of both sides

9. MASSETER
• Quadrilateral muscle
• Three layers of fibers
• Superficial layer
• Origin: anterior 2/3rd of lower
border of the zygomatic arch &
adjoining zygomatic process of
the maxilla
• Insertion: lower and posterior
part of the outer surface of
ramus of mandible
• Middle layer
• Origin: deep surface of anterior
2/3rd and lower border of the
posterior zygomatic arch
• Insertion: middle of mandibular
ramus
• Deep layer
• Origin: deep surface of
zygomatic arch
• Insertion: Upper and anterior
part of lateral surface of ramus
of mandible including a part of
coronoid process

10. MASSETER
• Vascular supply
• Masseteric branch of maxillary artery, facial artery and the
transverse facial branch of superficial temporal artery
• Innervation
• Masseteric branch of anterior trunk of mandibular nerve
• Action
• Strong elevator of mandible
• Superficial fiber help in protraction and deep fibers in
retraction of the mandible

11. NERVE INNERVATIONS