GROSS ANATOMY OF TEMPORAL AND INFRATEMPORAL FOSSAE

ATIBA, P.M.

TEMPORAL FOSSA

• Is a depression on the temporal region.

• Receives contribution from frontal, parietal, sphenoid and temporal bones.

• Superior to infratemporal fossa,

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Borders

• Superiorly and Posteriorly – Superior temporal line.

• Inferiorly – Zygomatic arch

• Anteriorly – frontal process of the zygoma and zygomatic process of frontal bone

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Contents

• Muscle

• Blood Vessels

• Nerves

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Muscle

• Temporalis

• Origin: Inferior temporal line of temporal fossa, temporal fascia

• Insertion: Apex and medial surface of coronoid process of mandible

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Muscle

• Innervation: Deep temporal branches of mandibular nerve (CN V3)

• Action: Elevates mandible (anterior fibres); retracts mandible (posterior part)

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Blood Vessels

• Superficial temporal artery – courses above the superficial temporal fascia. Gives off medial temporal artery to the temporal muscle (frontal and parietal branches –scalp).

• Superior temporal vein accompany the artery.

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Nerves

• The fossa contains four branches from four different nerve bundles. The terminal branches include:

• Branch of the mandibular nerve (V3)

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Nerves

• The auriculotemporal nerve.

• The temporal branches of facial nerve.

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Infratemporal fossa

• Is an irregular shaped space below the zygomatic arch and deep to the ramus of the mandible.

• Continues inferiorly with temporal fossa.

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Borders

• Superior- Greater wing of the sphenoid

• Inferior: medial pterygoid muscle

• Lateral: medial surface of ramus of the mandible

• Medial: lateral plate of sphenoid bone

• Posterior: Mastoid and styloid process

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Contents

• Nerves

• Blood vessels

• Muscles

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Muscles

• Superior head of the lateral pterygoid

• Inferior head of the lateral pterygoid

• Deep head of the medial pterygoid

• Superficial head of the medial pterygoid

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Nerves

• Mandibular nerve –branch of trigeminal nerve

• Enters the fossa via foramen ovale, gives off sensory and motor branches.

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Branches within Infratemporal fossa

• Branches arising from the trunk

• Spinous nerve

• Medial pterygoid nerve

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Branches within Infratemporal fossa

• Anterior branches

• Buccal nerve

• Masseteric nerve

• Deep temporal nerves

• Lateral pterygoid nerve

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Branches within Infratemporal fossa

• Posterior branches

• Auriculotemporal nerve

• Lingual nerve

• Inferior alveolar nerve

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Branches within Infratemporal fossa

• The spinous nerve passes through the spinous foramen and enters the cranium. It innervates the dura mater.

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Branches within Infratemporal fossa

• The medial pterygoid nerve- medial pterygoid, tensor velipalatini and tensor tympani muscles.

• Buccal nerve- inner surface of the cheek.

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Branches within Infratemporal fossa

• Masseteric nerve, deep temporal nerves, lateral pterygoid nerve innervates muscles with same name.

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Auriculotemporal nerve

• Gives sensory fibres to the auricle and temporal region

• Sends sensory fibres to the TMJ.

• Conveys postsynaptic parasympathetic secretomotor fibresfrom otic ganglion to the parotid gland.

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Inferior Alveolar nerve

• Enters the mandibular foramen and passes through the mandibular canal, forming the inferior dental plexus, which sends branches to all mandibular teeth on its side.

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Inferior alveolar nerve

• The terminal branch of the inferior alveolar nerve is the mental nerve which passes through the mental foramen.

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Lingual nerve

• Gives sensory to the anterior 2/3 of the tongue, floor of the mouth, and the lingual gingivae

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Chorda tympani nerve

• Branch of CN VII; carries taste fibresfrom anterior 2/3 of the tongue.

• Joins the lingual nerve in the infratemporal fossa

• Secretomotor fibres for submandibular and sublingual glands.

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Otic ganglion (parasympathetic)

• Located in the infratemporal fossa, just inferior to the foramen ovale.

• Presynaptic parasympathetic fibresderived mainly from CNIX (lesser petrosal nerve), synapse in the otic ganglion

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Otic ganglion (parasympathetic)

• Postsynaptic parasympathetic fibres, secretory to the parotid gland, pass from the oticganglion to this gland through the auriculotemporal nerve.

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Vasculature

• Maxillary artery- in this fossa, middle meningeal artery, passes through the superior border via foramen spinosum.

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Pterygoid venous plexus

• Drains the eye and is directly connected to the cavernous sinus.

• Provides a potential route for infections of the face to spread intracranially.

• Maxillary vein

• Middle Meningeal veinGross anatomy of temporal and infratemporal fossae 29

Applied anatomy

• The pterion is an important structure in cranial anatomy

• Point where temporal, parietal, frontal and sphenoid bones meet and its weakest spot on skull

• Trauma can lead to extradural haematoma

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