muscle of mastication, origin insertion, innervation andd action, messeter, temporalis muscle, medial pterygoid , lateral pterygoid

1. MUSCLES OF
MASTICATION
DR SANA YASEEN
ANATOMY DEPARTMENT
KIMS

2. Introduction
• Muscles mastication moves mandible during mastication and
speech. They are namely;
• Masseter
• Temporalis
• Lateral pterygoid
• Medial pterygoid
• Developed from 1st branchial arch
• Innervation mandibular nerve

4. MASSETER MUSCLE
ORIGIN INSERTION INNERVATION ACTION
SUPERFICIAL
LAYER:
MIDDLE LAYER:
DEEP LAYER:
Arise from zygomatic
arch
Ramus of mandible +
coronoid process of
mandible
Masseteric nerve (
anterior division of
mandibular nerve)
Elevates mandible to
close a mouth
• Quadralateral muscle
• Covers lateral surface o ramus of mandible
• Has 3 layers

5. MASSETER MUSCLE

6. TEMPORALIS MUSCLE
• Fan shape
• Fills the temporal fossa
ORIGIN INSERTION INNERVATION ACTION
Temporal fossa +
temporal fascia
Coronoid process +
ramus of mandible
Deep temporal
branches ( anterior
division of mandibular
nerve)
Elevates mandible
+retract the protuded
mandible + help in
side to side grinding
movement

8. LATERAL PTERYGOID MUSCLE
• Short, conical
• Has upper and lower head
ORIGIN INSERTION INNERVATION ACTION
Infratemporal surface+
crest of greater wing
of sphenoid+ lateral
pterygoid plate
Neck of mandible+
capsule of TMJ
A branches ( anterior
division of mandibular
nerve)
depress mandible to
open mouth +
protrudde mandible +
turn chin to left side as
during grinding

9. LATERAL PTERYGOID MUSCLE

10. MEDIAL PTERYGOID MUSCLE
• Quadrilateral
• Has superficial and deep head
ORIGIN INSERTION INNERVATION ACTION
Tuberosity of maxilla +
lateral pterygoid plate
+palatine bone
Angle and ramus of
mandible + mylohyoid
groove
Nerve to meddial
pterygoid ( main trunk
of mandibular nerve)
Elevates mandible +
protude mandible+
turns chin to left along
with lateral pterygoid