Anatomy: Infratemporal Fossa Flashcards
What is the lateral boundary of the ITF?
Ramus of the mandible
What is the superior border of the ITF?
Zygomatic arch
What is the posterior border of the ITF?
Tympanic plate and mastoid process
What is the anterior boundary of the ITF?
Posterior maxilla
What is the medial boundary of the ITF?
Lateral pterygoid plate
Where is the ITF in relation to Pterygopalatine fossa?
Medial
What are the muscles contained in the ITF?
Inferior part of temporalis
Medial pterygoid
Lateral pterygoid
What are the important nerves contained in the ITF?
- CN V3/c
- lingual nerve
- inferior alveolar nerve
- chorda tympani
In the ITF, what are the two main nerve branches of CN V3/c?
The inferior alveolar nerve and the lingual nerve
What are the two main arteries contained in the ITF?
- middle meningeal artery
- maxillary artery + branches
What is the function of the lateral pterygoid muscle?
Opens the jaw
Where is the origin of the superior head of the lateral pterygoid?
The infratemporal crest of greater wing of sphenoid
Where is the origin of the inferior head of the lateral pterygoid?
Lateral surface of pterygoid plate
Where does the lateral pterygoid muscle insert into?
The mandibular forea and TMJ capsule/articular disc
What nerve innervates the lateral pterygoid muscle?
CN V3/c
What is the function of the medial pterygoid muscle?
Closes the jaw
What is the origin of the deep head of the medial pterygoid muscle?
The medial surface of the lateral pterygoid plate
Where is the origin of the superficial head of the medial pterygoid muscle?
The tuberosity of the maxilla
Where does the medial pterygoid muscle insert?
The medial surface of the mandibular ramus
What nerve innervates the medial pterygoid muscle?
CN V3/c
What complex structure forms around the lateral pterygoid muscle?
The pterygoid venous plexus
What vein runs centrally through the venous plexus to the face?
The maxillary vein
What vein does maxillary vein branch from?
The retromandibular vein
What is the clinical relevance of the pterygoid plexus when giving a block injection?
Important consideration as accidental perforation could result in haematoma
Where does the maxillary artery branch from?
The external carotid artery
How many parts make up the maxillary artery?
3
What are the important arteries to remember in the 1st part of the maxillary artery?
- middle meningeal artery
- inferior alveolar artery
What are the important arteries to remember in the 2nd part of the maxillary artery?
- deep temporal arteries
- buccal artery
What are the important arteries to remember in the 3rd part of the maxillary artery?
- Sphenopalatine artery
- infra-orbital artery
- posterior superior alveolar artery
What nerve modality does the trigeminal ganglion ( arising directly from pons) have?
sensory
Where does the motor root unite with the sensory of CN V ?
Outside the cranial vault
What division of CN V is the only one to have both motor and sensory roots?
CN V3/c
What are the two divisions of the mandibular nerve?
Anterior and posterior
What are the motor nerve branches of the anterior part of CN V3?
Deep temporal
What is the sensory nerve branch of the anterior part of CN V3?
buccal nerve
What are the 5 branches of the posterior part of CN V3?
- auriculotemporal
- inferior alveolar nerve
- nerve to mylohyoid
- mental nerve
- lingual nerve
All nerves of the posterior aspect of the mandibular nerve are sensory. True or false?
False. The nerve to mylohyoid is motor.
Which two nerves of the posterior aspect of the mandibular nerve are most clinically relevant?
- inferior alveolar nerve
- lingual nerve
Describe the passage of nerve fibres from CN IX to the parotid gland
- 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
What CN is the chorda tympani a branch of?
CN VII
What nerve does the chorda tympani pass parasympathetic fibres through and “hitch a ride on” in order to innervate the submandibular and sublingual glands?
The lingual nerve branch of CN V3
What are the 4 key clinical importances of the ITF?
- muscles involved in movement of mandible/mastication
- blood supply to teeth via maxillary artery
- pterygoid plexus
- mandibular nerve and relationships
How can infection of the ptrygoid plexus arise?
Due to communication between the superficial face and dural venous sinuses ( pterygoid plexus inferior to cavernous sinus)
