Anatomy: Infratemporal Fossa

Question 1

What is the lateral boundary of the ITF?

Answer 1

Ramus of the mandible

Question 2

What is the superior border of the ITF?

Answer 2

Zygomatic arch

Question 3

What is the posterior border of the ITF?

Answer 3

Tympanic plate and mastoid process

Question 4

What is the anterior boundary of the ITF?

Answer 4

Posterior maxilla

Question 5

What is the medial boundary of the ITF?

Answer 5

Lateral pterygoid plate

Question 6

Where is the ITF in relation to Pterygopalatine fossa?

Answer 6

Medial

Question 7

What are the muscles contained in the ITF?

Answer 7

Inferior part of temporalis
Medial pterygoid
Lateral pterygoid

Question 8

What are the important nerves contained in the ITF?

Answer 8

• CN V3/c
• lingual nerve
• inferior alveolar nerve
• chorda tympani

Question 9

In the ITF, what are the two main nerve branches of CN V3/c?

Answer 9

The inferior alveolar nerve and the lingual nerve

Question 10

What are the two main arteries contained in the ITF?

Answer 10

• middle meningeal artery
• maxillary artery + branches

Question 11

What is the function of the lateral pterygoid muscle?

Answer 11

Opens the jaw

Question 12

Where is the origin of the superior head of the lateral pterygoid?

Answer 12

The infratemporal crest of greater wing of sphenoid

Question 13

Where is the origin of the inferior head of the lateral pterygoid?

Answer 13

Lateral surface of pterygoid plate

Question 14

Where does the lateral pterygoid muscle insert into?

Answer 14

The mandibular forea and TMJ capsule/articular disc

Question 15

What nerve innervates the lateral pterygoid muscle?

Answer 15

CN V3/c

Question 16

What is the function of the medial pterygoid muscle?

Answer 16

Closes the jaw

Question 17

What is the origin of the deep head of the medial pterygoid muscle?

Answer 17

The medial surface of the lateral pterygoid plate

Question 18

Where is the origin of the superficial head of the medial pterygoid muscle?

Answer 18

The tuberosity of the maxilla

Question 19

Where does the medial pterygoid muscle insert?

Answer 19

The medial surface of the mandibular ramus

Question 20

What nerve innervates the medial pterygoid muscle?

Answer 20

CN V3/c

Question 21

What complex structure forms around the lateral pterygoid muscle?

Answer 21

The pterygoid venous plexus

Question 22

What vein runs centrally through the venous plexus to the face?

Answer 22

The maxillary vein

Question 23

What vein does maxillary vein branch from?

Answer 23

The retromandibular vein

Question 24

What is the clinical relevance of the pterygoid plexus when giving a block injection?

Answer 24

Important consideration as accidental perforation could result in haematoma

Question 25

Where does the maxillary artery branch from?

Answer 25

The external carotid artery

Question 26

How many parts make up the maxillary artery?

Answer 26

3

Question 27

What are the important arteries to remember in the 1st part of the maxillary artery?

Answer 27

- middle meningeal artery - inferior alveolar artery

Question 28

What are the important arteries to remember in the 2nd part of the maxillary artery?

Answer 28

- deep temporal arteries - buccal artery

Question 29

What are the important arteries to remember in the 3rd part of the maxillary artery?

Answer 29

- Sphenopalatine artery - infra-orbital artery - posterior superior alveolar artery

Question 30

What nerve modality does the trigeminal ganglion ( arising directly from pons) have?

Answer 30

sensory

Question 31

Where does the motor root unite with the sensory of CN V ?

Answer 31

Outside the cranial vault

Question 32

What division of CN V is the only one to have both motor and sensory roots?

Answer 32

CN V3/c

Question 33

What are the two divisions of the mandibular nerve?

Answer 33

Anterior and posterior

Question 34

What are the motor nerve branches of the anterior part of CN V3?

Answer 34

Deep temporal

Question 35

What is the sensory nerve branch of the anterior part of CN V3?

Answer 35

buccal nerve

Question 36

What are the 5 branches of the posterior part of CN V3?

Answer 36

- auriculotemporal - inferior alveolar nerve - nerve to mylohyoid - mental nerve - lingual nerve

Question 37

All nerves of the posterior aspect of the mandibular nerve are sensory. True or false?

Answer 37

False. The nerve to mylohyoid is motor.

Question 38

Which two nerves of the posterior aspect of the mandibular nerve are most clinically relevant?

Answer 38

- inferior alveolar nerve - lingual nerve

Question 39

Describe the passage of nerve fibres from CN IX to the parotid gland

Answer 39

- CN IX sends pre-syntaptic parasympathetic fibres to OTIC GANGLION - parasympathetic fibres ‘ hitch a ride’ via the auriculotemporal branch of CN V3 to reach the parotid gland

Question 40

What CN is the chorda tympani a branch of?

Answer 40

CN VII

Question 41

What nerve does the chorda tympani pass parasympathetic fibres through and “hitch a ride on” in order to innervate the submandibular and sublingual glands?

Answer 41

The lingual nerve branch of CN V3

Question 42

What are the 4 key clinical importances of the ITF?

Answer 42

- muscles involved in movement of mandible/mastication - blood supply to teeth via maxillary artery - pterygoid plexus - mandibular nerve and relationships

Question 43

How can infection of the ptrygoid plexus arise?

Answer 43

Due to communication between the superficial face and dural venous sinuses ( pterygoid plexus inferior to cavernous sinus)