Download Infratemporal region and Pterygopalatine fossa

BMES216 Human Skeletal and Muscular Systems
Infratemporal fossa
Kittikun Viwatpinyo, Ph.D.
Infratemporal region
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The area in the head medial
to zygomatic arch and
ramus of mandible, and
inferior to temporal fossa
Bony framework
Bony framework
Bony framework : Temporal
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Mandibular fossa
Articular tubercle
Zygomatic process
Tympanic part
Bony framework : Sphenoid
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Greater wing & Infratemporal crest
Lateral pterygoid plate : attachment of pterygoid muscles
Spine of sphenoid
Bony framework : Sphenoid
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Foramen spinosum : Middle meningeal a.
Foramen ovale : Mandibular n.
Bony framework : Zygomatic
Bony framework : Maxilla
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Tuberosity of maxilla
Posterior superior alveolar foramen
Pterygomaxillary fissure
Bony framework : Mandible
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Ramus, angle and body of mandible
Upper border of ramus of mandible
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Coronoid process
Condylar process : head and neck of mandible
Bony framework : Mandible
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Medial surface of mandible
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Mandibular foramen and
canal
Lingula
Mylohyoid groove (for N. to
mylohyoid)
Temporomandibular joint
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TMJ is a modified hinge type synovial joint between
mandibular fossa of temporal bone and head of mandible
Articular disc between articular surfaces separates joint
capsule into 2 compartments :
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Lower compartment : Hinge movement
Upper compartment : Gliding movement
Temporomandibular joint
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Opening of jaw ➔ Transition of head of mandible anteriorly
toward articular tubercle
Temporomandibular joint
Temporomandibular joint
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Extracapsular ligaments :
support joint stability
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Lateral (temporomandibular)
ligament
Sphenomandibular ligament
Stylomandibular ligament
Temporomandibular joint
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Movements of mandible
through TMJ :
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Depression
Elevation
Protrusion
Retraction
Side-to-side
Temporomandibular joint
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Overt movement
➔ Head of
mandible moves
anterior to
articular tubercle
➔ Dislocation of
TMJ
Muscles of mastication
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Masseter muscle
Muscles of mastication
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Temporalis muscle
Muscles of mastication
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Medial pterygoid muscle
Muscles of mastication
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Lateral pterygoid muscle
Muscles of mastication (All innervated by CN. V3)
Muscle
Masseter
Origin
Zygomatic arch and
maxillary process of
zygomatic bone
Insertion
Action via TMJ
Lateral surface of ramus Elevation
and angle of mandible
Temporalis
Temporal fossa and
fascia
Coronoid process and
Anterior fibers : Elevation
anterior margin of ramus Posterior fibers : Retraction
of mandible
Medial
pterygoid
Tuberosity of maxilla Medial surface of angle
Medial surface of
of mandible
lateral pterygoid plate
Lateral
pterygoid
Infratemporal crest
Pterygoid fovea on neck Protrusion and side-to-side
Lateral surface of
of mandible and fibrous movements
lateral pterygoid plate capsule of TMJ
Elevation and side-to-side
movements
Masticator spaces
• Infratemporal space
• Temporal space
Masticator spaces
• Submasseteric space
• Pterygomandibular space
Nerves of infratemporal region
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Mandibular division of Trigeminal nerve (CN. V3)
Autonomic nervous system
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Chorda tympani
Lesser petrosal nerve
Otic ganglion
Nerves of infratemporal region
Nerves of infratemporal region
CN. V3 : Anterior trunk
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Buccal nerve
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sensory nerve to buccal mucosa, buccal surface of gingiva of lower molars and
skin of cheek
Masseteric nerve, Deep temporal nerve, Nerve to lateral pterygoid
CN. V3 : Posterior trunk
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Auriculotemporal nerve
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Sensory from TMJ and skin of anterior part of external ear, parotid
region and temporal region
CN. V3 : Posterior trunk
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Lingual nerve
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Sensory from anterior 2/3 of tongue (general sense), oral mucosa of
floor of oral cavity and lingual surface of gingiva
CN. V3 : Posterior trunk
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Inferior alveolar nerve
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Sensory from lower teeth and skin of
lower lip and chin (from mental n.)
• Nerve to mylohyoid muscle
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Motor to mylohyoid muscle and
anterior belly of digastric muscle
CN. V3 : Posterior trunk
• Inferior alveolar nerve block
Autonomic fibers
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Parasympathetic supply to salivary glands
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Chorda tympani n.  Lingual n.  Submandibular gg.
 Submandibular & sublingual glands
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Lesser petrosal n.  Otic gg.  Auriculotemporal n. 
Parotid gland
Autonomic fibers
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Parasympathetic supply to salivary glands
Autonomic fibers
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Chorda tympani (branch from CN. VII)
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Carries two types of nerve fibers :
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Taste sensory from anterior 2/3 of tongue
Preganglionic parasympathetic fibers to submandibular gg
Autonomic nerves
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Lesser petrosal nerve
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A branch of glossopharyngeal nerve (CN. IX) via tympanic plexus
Carries preganglionic para-sympathetic fibers to otic ganglion
Maxillary artery
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Maxillary artery is the largest branch of external carotid artery,
and a major artery in infratemporal region
Three parts (according to relationship with lateral pterygoid m.)
Maxillary artery
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Middle meningeal artery
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Mostly from 1st part
Passes upward and enters
cranial cavity through
Foramen spinosum
Supplies major parts of
meninges
Damage of artery : Epidural
hemorrhage
Maxillary artery
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Inferior alveolar artery
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Passes downward into mandibular foramen with inferior alveolar n.
Supplies lower teeth, buccal side of gingiva, and also lower lip and chin
(by mental artery)
Pterygoid venous plexus
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Pterygoid plexus is a major venous drainage of infratemporal region
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drains into retromandibular vein and deep facial vein
Route of infection from superficial head into deep head