Infratemporal fossa

BMES208 Human Musculoskeletal System

Kittikun Viwatpinyo, Ph.D.

Infratemporal fossa : area in the head medial to zygomatic arch and ramus of mandible, and inferior to temporal fossa

Infratemporal fossa : Intro

(Agur & Dalley, 2008)

Walls of infratemporal fossa composed of 5 bones : Temporal bone, Sphenoid bone, Zygomatic bone, Maxilla and Mandible.

Infratemporal fossa : Bony walls

(Agur & Dalley, 2008)

Infratemporal fossa : Bony walls

(Agur & Dalley, 2008)

Infratemporal fossa : Bony walls

(Drake, Wayne & Mitchell, 2005)

Body of mandible Ramus of mandible◦ Condylar process◦ Coronoid process◦ Mandibular foramen◦ Lingula◦ Mylohyoid groove

Mandible

Tank, 2005)

TMJ is a modified hinge type synovial joint between mandibular fossa of temporal bone and head of mandible

Temporomandibular joint

(Agur & Dalley, 2008)

Articular disc separates joint capsule into 2 compartments : ◦ Lower compartment : Hinge movement◦ Upper compartment : Gliding movement

Temporomandibular joint

(Drake, Wayne & Mitchell, 2005)

(Moore, Dalley & Agur, 2010)

Extracapsular ligaments of TMJ◦ Lateral (Temporomandibular) ligament◦ Sphenomandibular ligament◦ Stylomandibular ligament

Temporomandibular joint

(Drake, Wayne & Mitchell, 2005)

Movements through TMJ :◦ Elevation-Depression◦ Protrusion-Retraction◦ Lateral movement (side-to-side)

Temporomandibular joint

(Drake, Wayne & Mitchell, 2005)

(Moore, Dalley & Agur, 2010)

Masseter m. Temporalis m.

Muscles of mastication

(Drake, Wayne & Mitchell, 2005)

Lateral pterygoid m.

Muscles of mastication

(Drake, Wayne & Mitchell, 2005)

Medial pterygoid m.

Muscles of mastication

(Drake, Wayne & Mitchell, 2005)

Branches of Mandibular nerve (CN. V3) Autonomic nerves : ◦ Chorda tympani ◦ Lesser petrosal nerve

Nerves of infratemporal fossa

(Agur & Dalley, 2008)

Muscular branches : Masseteric n., Deep temporal n. Buccal nerve : sensory from cheek and buccal mucosa

Mandibular nerve : Anterior trunk

(Drake, Wayne & Mitchell, 2005)

Auriculotemporal nerve ◦ Sensory from TMJ and skin of parotid and temporal region◦ Postganglionic parasym fibers to parotid gland

Mandibular nerve : Posterior trunk

(Drake, Wayne & Mitchell, 2005)

Lingual nerve◦ Sensory from anterior 2/3 of tongue and floor of oral mucosa◦ Chorda tympani nerve joins lingual nerve

Mandibular nerve : Posterior trunk

(Drake, Wayne & Mitchell, 2005)

Inferior alveolar nerve◦ Sensory from lower teeth & skin from lower lip and chin (via

mental nerve)◦ Nerve to mylohyoid : motor to mylohyoid and anterior belly of

digastric

Mandibular nerve : Posterior trunk

(Drake, Wayne & Mitchell, 2005)

Chorda tympani nerve◦ Postganglionic parasym fibers to submandibular &

sublingual glands◦ Taste from anterior 2/3 of tongue

Autonomic nerves

(Drake, et al., 2007)

Lesser petrosal nerve◦ Preganglionic parasym fibers to Otic ganglion, which sends

postganglionic parasym fibers to parotid gland via auriculotemporal nerve

Autonomic nerves

(Drake, et al., 2007)

Maxillary artery is the largest branch of external carotid artery, and a major artery in infratemporal region

Three parts (relate to lateral pterygoid m.)

Maxillary artery

Tank, 2005)

Middle meningeal artery◦ 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

(Drake, Wayne & Mitchell, 2005)

(Moore, Dalley & Agur, 2010)

Inferior alveolar artery◦ From 1st part, 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)

Maxillary artery

(Drake, Wayne & Mitchell, 2005)

Pterygoid plexus is a major venous drainage of infra-temporal region◦ Receives blood from cranial cavity, orbit, nasal and oral

cavities, and drains into retromandibular vein and deep facial vein

Pterygoid venous plexus

(Drake, Wayne & Mitchell, 2005)