Lecture 11: Infratemporal Fossa and Pterygopalatine fossa Flashcards
What are the boundaries of the infratemporal fossa :
roof, anterior wall, lateral wall and medial wall (anterior to post)
(open to neck posteroinferiorly, underneath and underneath the zygomatic arch)
Roof: Inferior surface of the greater wing of the sphenoid + temporal bone
Anterior wall: Posterior surface of maxilla
Lateral wall: Medial surface of ramus of the mandible
Medial wall: anterior to post:
- Lateral plate of the pterygoid process
- Muscles of the soft palate:
- Tensor veli palatine and then Levator veli palatine
What is the main joint within the infratemporal fossa- what bones + others does this type of joint include
Temporomandibular joint between the mandibular condyle and the mandibular fossa of the temporal bone.
There is a cartilaginous articular disc that separates them into upper and lower joint cavity
What are the 3 ligaments that contribute to or attach to the joint capsule for TMJ.
Which is a content of the infratemporal fossa- say th origin and insertion
Sphenomandibular, Lateral and Stylomandibular ligament
Sphenomandibular is a content:
origin= spine of sphenoid bone
insertion: lingula of the mandible and posterior margin of the mandibular foramen
What are the muscles that cause Depression of the jaw
+ gravity
- Digastric,
- geniohyoid, and
- mylohyoid muscles
(lateral pterygoid muscles also involved in the forward movement of the head of mandible into the mandibular fossa
What are the origin and insertion of the Lateral pterygoid muscles (upper + lower head)
Lat:
- Upper: From roof of infratemporal fossa,
- Lower from lateral surface of lateral pterygoid process
to capsule of TMJ
What are the muscles involved in the Elevation of the jaw and where do they attach
- Temporalis (temporal fossa to the coronoid process of mandible)
- Masseter muscle (zygomatic arch to the angle of the mandible)
- Medial pterygoid muscles
What are the muscles involved in the Retraction of the jaw and where do they attach
- Posterior fibres of temporalis
- Deep part of Masseter
- Geniohyoid
- Digastric
What are the muscular and nervous contents of the infratemporal fossa :
Muscle
- lateral and medial pterygoid muscles
- sphenomandibular ligament
Nervous structures travelling through
- CNV3 : (muscles of mastication)
- Branches of the CN9 - lesser petrosal nerve
- Branches of the CN7- chorda tympani
What cranial fossa opens into the infratemporal fossa and what does it contain - what are the 2 trunks and their branches (4A, 3P)
Foramen ovale
- Lesser petrosal
- CNV3
Anterior trunk
-Buccal, Masseteric, Deep temporal and Nerve to lateral pterygoid- all motor except buccal
Posterior trunk
- Auriculotemporal, lingual, and inferior alveolar nerves- all sensory except inferior alveolar branch
What is the source of the Mental nerve and the incisive nerve.
Mental and Incisive nerve is from inferior alveolar nerve
What are the 3 small nerves (and their CNroots) that runs in the infratemporal fossa
- Chorda tympani (CN7)- passes straight into infratemporal fossa and runs with
- Lingual nerve (CNV3)
- Lesser Petrosal nerve (CN9) - enters through foramen ovale and synapse at the otic ganglion on the medial side of mandibular nerve where post ganglionic fibres go to join the auriculotemporal (CNV3) nerve to the parotid gland
What are the venous contents of the infratemporal fossa - including clinical notes
Venous:
- Pterygoid plexus - network of veins between medial and lateral pterygoid muscles
- Connected to cavernous sinus via emissary veins passing through foramen ovale
What are the arterial contents of the infratemporal fossa + branches
including clinical notes
Maxillary artery: major branch of the Ext Carotid
- Middle meningeal artery
- Inferior alveolar
Inside the infratemporal fossa
- Deep temporal, Masseteric, buccal and pterygoid branches which course with anterior trunk branches of CNV3
Clinical is that in trauma in ED
1st MMA examined bc blood supply to the meninges
2nd Inferior alveolar because it is a big artery which can lead to bleeding out.
What are the anterior, medial, posterior border and roof of the pterygopalatine fossa
Pterygopalatine fossa is found 2-3mm deeper than the infratemporal fossa
Anterior: Posterior wall of the maxilla
Medial: Lateral surface of palatine bone
Posterior and Roof: sphenoid bone-it is within the sphenoid bone
What is the fissure that makes the infratemporal fossa continuous with the pterygopalatine fossa
door to the pterygopalatine fossa: Pterygomaxillary fissure