Areas - Infratemporal Fossa

Question 1

What is the infratemporal fossa?

Answer 1

A complex area located deep to the masseter muscle.

Question 2

Borders of the infratemporal fossa?

Answer 2

Said to be wedge-shaped.

Located deep to the masseter and the zygomatic arch.

It is close association with the temporal and pterygopalatine fossae.

Lateral - condylar process and ramus of the mandible bone

Medial - lateral pterygoid plate; tensor veli palatine, levator veli palatine and superior constrictor muscles

Anterior - posterior border of the maxillary sinus

Posterior - carotid sheath

Roof - greater wing of the sphenoid bone

Flooe - medial pterygoid muscle

Question 3

Roof - greater wing of sphenoid

Associated foramen?

Contents?

Answer 3

1) Foramen ovale - mandibular nerve, lesser petrosal nerve, accesory meningeal artery.
2) Foramen spinosum - middle meningeal artery, vein and nervus spinosus that supplies the dura mater.

Question 4

Contents of the infratemporal fossa - muscles?

Answer 4

Muscles of mastication - medial and lateral pterygoid muscles. The masseter and temporalis inserts into the borders of the fossa.

Question 5

Contents of the infratemporal fossa - nerves?

Answer 5

1) Mandibular nerve (a branch of the trigeminal) - gives rise to motor and sensory branches.
2) Branches of the trigeminal nerve - auriculotemporal, buccal, lingual and inferior alveolar nerves.
3) Chorda tympani - follow the course of the lingual nerve - a branch of the facial nerve provides anterior 2/3 tongue taste sensation.
4) Otic ganglion - a parasympathetic collection of neuronal cell bodies. Nerve fibres of this ganglion ‘hitch hike’ along the auriculotemporal nerve to reach the parotid gland.

Question 6

Contents of the infratemporal fossa - vasculature?

Answer 6

Contains several vasculature structures:

1) Maxillary artery - terminal branch of the external carotid artery.

Within the fossa it gives rise to the middle meningeal artery, which passes through the foramen spinosum.

2) Pterygoid venous plexus - drains the eye and is directly connected to the cavernous sinus.
3) Maxillary vein
4) Middle meningeal vein

Question 7

Clinical relevance: Pterion fracture

Answer 7

The pterion is the point at which the temporal, parietal, frontal and sphenoid bones meet.

Trauma to this area can lead to an extradural haematoma as the middle meningeal artery lies deep to it.

This may lead to intra-cranial pressure, which may lead to herniation of the brain tissue and ischaemia.

Symptoms of intra-cranial pressure - nausea, vomiting, seizures, bradycardia and limb weaknesses.

Treated by diuretics, in minor cases, or by burr holes into the skull in more extreme cases.