Infratemporal fossa

Question 1

Boundaries?

Answer 1

Lateral pterygoid plate
Infratemporal surface of greater wing of sphenoid and squamous part of temporal bone.
Styloid process
Posterior wall of maxilla.

Question 2

Contents?

Answer 2

Mandibular division of trigeminal (V3)
Fo. ovale
Maxillary artery (part 1 and 2) and the branches
Maxillary vein
Otic ganglion
Chorda tympani (branch of facial nerve innervates taste senses to anterior 2/3 of the tongue)
Lateral and medial pterygoid muscles.

Question 3

Attachments and functions of lateral and medial pterygoid muscles?

Answer 3

Medial pterygoid muscles - found deep to lateral pterygoid muscles.
Attachments superiorly - lateral pterygoid plate, pterygopalatine tissue and maxillary tuberosity.
Attachments inferiorly - mandible.
Function - superior and deep head are both elevators.

Lateral pterygoid muscles - found superficial to medial pterygoid muscles.
Attachments superiorly - lateral pterygoid plate and roof of the infratemporal fossa.
Attachments inferiorly - mandible.
Function - inferior head = protractor, superior head = elevator.

Question 4

Through what foramen does V3 exit the skull?

Answer 4

Fo. Ovale

Question 5

Describe the branching of V3 in the fossa (not the innervations)

Answer 5

Main trunk splits into anterior and posterior divisions.
Anterior division branches into long buccal nerve.
Posterior divison branches into auriculotemporal, lingual, inferior alveolar and nerve to mylohyoid.

Question 6

What are the innervations of the branches of the anterior division of V3?

Answer 6

Most of the anterior division branches are motor except long buccal nerve.
Long buccal nerve - sensory innovation to the cheeks and mandibular buccal gingiva.

Question 7

What are the innervations of the branches of the posterior divisions of V3?

Answer 7

Most of the posterior division branches are sensory except nerve to mylohyoid.
Auriculotemporal - wraps around middle meningeal artery and sends sensory branches to the temple.
Lingual - sensory innervation the the anterior 2/3 of the tongue, mandibular lingual gingiva, and sensory fibres to submandibular ganglion.
Inferior alveolar nerve - innervates the tooth substance fo the mandibular teeth
Nerve to mylohyoid - motor innervation to mylohyoid and anterior belly of digastric.

Question 8

What are the 3 parts of the maxillary artery and where are they located?

Answer 8

Before, beneath and beyond the lateral pterygoid muscle.

Parts 1 and 2 found in the infra temporal fossa, 3rd part found in the pterygopalatine fossa.

Question 9

What are the branches of the 1st and 2nd part of the maxillary artery?

Answer 9

1st part - middle meningeal artery (enters skull through fo. spinosum), inferior alveolar artery (follows same route as inferior alveolar nerve).
2nd part has muscular and cutaneous branches.

Question 10

Describe the branching of the maxillary vein and where it drains

Answer 10

Has the same tributaries as the branches of the maxillary artery.
Drains into the retromandibular vein

Question 11

What are the incoming fibres of the otic ganglion?

Answer 11

Parasympathetic root - lesser petrosal nerve (branch of glossopharyngeal nerve) through fo. ovale
Sympathetic root - from a plexus on the middle meningeal artery.
Sensory root - from V3

Question 12

What are the outgoing fibres of the otic ganglion?

Answer 12

Branches of distribution - from ganglion to parotid gland via the auriculotemporal nerve.
Somatic motor root - from ganglion to the medial pterygoid muscle.