1. Muscles of mastication
Temporal fossa
Infratemporal fossa
Muscles of mastication
Kritchai Bespinyowong

2. Temporal fossa Boundaries : Above & behind - superior temporal line
Anterior wall - zygomatic bone
- zygomatic process of frontal bone
- greater wing of sphenoid bone
Medial wall - parietal bone, frontal bone,
squamous part of temporal bone,
greater wing of sphenoid bone
Inferior - infratemporal crest

4. Temporal fascia

5. Infratemporal fossa Boundaries :
Anterior wall - posterior surface of maxilla
- maxillary tuberosity
Medial wall - lateral pterygoid plate
- pyramidal process of palatine bone
Lateral wall - inner surface of zygomatic arch
- ramus and coronoid process
Roof - infratemporal surface of greater
wing of sphenoid bone and
squamous part of temporal bone

6. Infratemporal fossa Route : cranial cavity orbit infratemporal fossa
pterygopalatine fossa
Foramen ovale
Foramen spinosum
Inferior orbital fissure
Pterygomaxillary fissure

7. Infratemporal fossa Contents : 1. Medial & Lateral pterygoid muscle
2. Maxillary artery
3. Pterygoid venous plexus
4. Mandibular nerve
5. Chorda tympani
6. Otic ganglion

9. Medial pterygoid muscle Lateral pterygoid muscle
Muscles of mastication
Masseter muscle
Temporalis muscle
Medial pterygoid muscle
Lateral pterygoid muscle

10. Masseter muscle Origin :
superficial portion - lower border of ant. 2/3 of
zygomatic arch
deep portion - lower border of post. 1/3 of
- medial surface of zygomatic
arch
Insertion : lateral surface of mandible extend from
basal part of coronoid process to angle
of mandible

12. Masseter muscle Nerve supply : Nerve to masseter
Action : - elevation (bilateral)
- retrusion (bilateral)
- ipsilateral excursion (unilateral)

13. Tempolaris muscle Origin : floor of temporal fossa
Insertion : medial surface, apex, anterior and posterior border of coronoid process
superficial tendon - anterior border of coronoid process
deep tendon - internal oblique line

15. Temporalis muscle Nerve supply : deep temporal branch of
mandibular nerve
Action : - resting tonus (bilateral)
- elevation (bilateral)
- retrusion (bilateral)
- ipsilateral excursion (unilateral)

16. Medial pterygoid muscle
Origin :
superficial head - maxillary tuberosity
- lateral surface of pyramidal process of palatine bone
deep head - pterygoid fossa
- medial surface of lateral
pterygoid plate
Insertion : medial surface of mandibular angle

18. Medial pterygoid muscle
Nerve supply : nerve to medial pterygoid
Action : - elevation (bilateral)
- protrusion (bilateral)
- contralateral excursion (unilateral)

19. Lateral pterygoid muscle
Origin :
upper head- infratemporal surface and infratemporal crest of greater wing
of sphenoid bone
lower head - lateral surface of lateral
pterygoid plate
Insertion : - anteromedial surface of
articular capsule
- anterior border of articular disc
- anterior surface of mandibular neck

21. Lateral pterygoid muscle
Nerve supply : nerve to lateral pterygoid
Action : - protrusion (bilateral)
- depression (bilateral)
- contralateral excursion (unilateral)

22. “จบแล้วฮับ”