Infratemporal Fossa

Question 1

What are the boundaries of the Infratemporal fossa

Answer 1

• Lateral - ramus of mandible
• Medial - lateral pterygoid plate
• Anterior - posterior aspect of maxilla
• Posterier - TMJ
• Superior - Inferior surface of sphenoid
• Inferior - attachment of medial pterygoid to angle of mandible

Question 2

What are the contents of the Infratemporal fossal

Answer 2

• Muscles - Inferior temporalis, lateral and medial pterygoid
• Vasculature - Maxillary artery, pterygoid venous plexus, maxillary vein
• Nerves - mandibular nerve and branches, PSA nerve, chorda tympani, otic ganglion

Question 3

What muscle has head which inserts into the TMJ capsule and disc, as well as a head inserting into the neck of the mandibular condyle

Answer 3

• Lateral pterygoid

Question 4

Nerve supply for Lateral Pterygoid:

Answer 4

Lateral pterygoid branch of V3

Question 5

Blood supply for lateral pterygoid muscle:

Answer 5

Pterygoid branch of maxillary artery

Question 6

Lateral pterygoid action (3):

Answer 6

Open mouth, protrude mandible, and deviate to opposite side

Question 7

What muscle has a head (one of two) that originates at the maxillary tuberosity and inserts into the angle of mandible medially

Answer 7

Medial pterygoid muscle

Question 8

Nerve supply and blood supply for medial pterygoid muscle:

Answer 8

• Nerve supply - medial pterygoid branch of V3
• Blood supply - pterygoid branch of maxillary artery

Question 9

Action of Medial pterygoid muscle:

Answer 9

Elevate the mandible

Question 10

Where is the pterygoid venous plexus located?

What is important about it?

Answer 10

Infratermporal fossa. It has no valves so blood flow bidirectional. Communicates with cavernous sinus.

Question 11

The inferior dental alveolar nerve originates from the posterior division of the mandibular nerve. What branches off just before entry into the mandibular foramen?

Answer 11

Mylohyoid branch

Question 12

Where does the lingual nerve lie in relation to the interior dental alveolar nerve?

Answer 12

Anterior. Runs down medial wall of mandible close to third molar, whilst IDN is within the bone.

Question 13

The infratemporal fossa has a lot of communications with the orbit, temporal fossa, cranial space (through foramina), pterygomandibular space and pterygopalatine fosa. What is the clinical relevance of this?

Answer 13

In health individuals these communication zones are filled with loose areolar tissue, but in pathological conditions these are pathways of least resistance.

Question 14

What is the name of the space within the infratemporal fossa where the IDB and lingual nerves are blocked

Answer 14

Pterygomandibular space

Question 15

List 5 landmarks for IDB

Answer 15

• Coronoid notch
• Pterygomandibular raphe
• Mandibular premolar teeth on opposite side
• Mandibular occlusla plane
• Posterior border of mandible

Question 16

The veins of the pterygoid venous plexus can be damaged during local to extract upper molar teeth. What can this result in:

Answer 16

Haematoma and trismus

Question 17

You give an LA and the skin blanches. Why?

Answer 17

You’ve injected into the Maxillary artery leading to the facial artery branch.

Can cause temporary blanching, burning sensation or ocular complications.

Question 18

Is the pterygoid plexus more likely to be damaged during upper or lower tooth treatment?

Answer 18

Upper.

Question 19

5 clinical features of infratemporal fossa infection

Answer 19

• Severe pain
• Swelling of the face
• Trismus
• Difficulty swallowing
• Fever

Can happen as a result of spread of infection from upper wisdom teeth, upward spread from pterygomandibular space, or injured pterygoid plexus during local resulting in abscess and haematoma

Question 20

What is Frey’s Syndrome?

Answer 20

Where auriculotemporal nerve has been damaged, and on repair the pathways cross over, so that when a person eats they sweat instead of salivate.