This presentation is for the medical student specially for the dental student. thank you.

1. Riddhi Dave

3.  There are main FOUR muscle which are
involved in mastication.
 1) TEMPORALIS
 2) MASSETER
 3) LATERAL PTERYGOID
 4) MEDIAL PTERYGOID

7.  INTRODUCTION
 Temporalis muscle is fan shape muscle.
 It fills the temporal fossa.
 ORIGIN
 Temporal fossa excluding the zygomatic bone.
 Temporal fascia.
 FIBERS
 Anterior fibers run vertically.
 Middle fibers run obliquely.
 Posterior fibers run horizontally.
 All converge and pass through gap deep to
zygomatic arch.

9.  INSERTION
 Margins and deep surface of coronoid
process.
 Anterior border of ramus of mandible.
 NERVE SUPPLY
 Two deep temporal branches from anterior
division of mandibular nerve.
 ACTION
 Elevates mandible
 Helps in side to side grinding movement
 Posterior fibers retract the mandible

11.  INTRODUCTION
 It is quadrilateral in shape.
 It is antigravity muscle.
 It covers the lateral surface of ramus of
mandible, and it has two layers.
 ORIGIN
 Superficial layer(largest) :- from anterior 2/3
rd of lower border of zygomatic arch and
adjoining zygomatic process of maxilla.
 Deep layer(small) :- from deep surface of
zygomatic arch.

13.  FIBERS
 Superficial fibers pass downwards and
backwards at 45 degree.
 Deep fibers pass vertically downwards.
 INSERTION
 Superficial layer :- into lower part of lateral
surface of ramus of mandible.
 Deep layer :- into rest of the ramus of
mandible.
 NERVE SUPPLY
 Masseteric nerve

14.  ACTION
 Elevates the mandible to close the mouth for
bite.

16.  INTRODUCTION
 Short , conical muscle.
 It has two heads upper and lower head.
 ORIGIN
 Upper head(small) :- from infratemporal
surface and crest of greater wing of sphenoid
bone.
 Lower head(larger) :- from lateral surface of
the lateral pterygoid plate.
 FIBERS
 Fibers run backward and laterally and
converge for insertion.

18.  INSERTION
 Pterygoid fovea on the anterior surface of
neck of mandible.
 Anterior margin of articular disc and capsule
of TMJ.
 NERVE SUPPLY
 Nerve to lateral pterygoid branch of
mandibular nerve.

19.  ACTION
 Depresses mandible to open mouth with
suprahyoid muscle.
 Lateral and medial pterygoid protrude
mandible.
 Right lateral and medial pterygoid muscle
turn the chin on left side as part of grinding
movements.

23.  INTRODUCTION
 It is a quadrilateral muscle.
 It has small superficial and large deep
muscle.
 ORIGIN
 Superficial head :- from tuberosity of maxilla
and adjoining bone.
 Deep head :- from medial surface of lateral
pterygoid plate.
 FIBERS
 Fibers run downwards , backwards and
laterally.

25.  INSERTION
 Roughened area on the medial surface of the
angle and adjoining ramus of mandible, below
and behind the mandibular foramen and
mylohyoid groove.
 NERVE SUPPLY
 Nerve to medial pterygoid which is a branch of
the main trunk of mandibular nerve.
 ACTION
 Elevates the mandible
 Protrude the mandible
 Right lateral and medial pterygoid muscle turn
the chin on left side as part of grinding
movements.

26.  SUPERFICIAL RELATIONS
 Lateral pterygoid plate
 Lingual nerve
 Inferior alveolar nerve
 DEEP RELATIONS
 Tensor veli palatini
 Superior constictor of pharynx
 Styloglossus