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
What are the places that the pterygopalatine foramen open up to and what are the names of the holes
- Nasal cavity
- sphenopalatine foramen - Floor of orbit
- Inferior orbital fissure - Infratemporal fossa
- Pterygomaxillary fissure - Cranial cavity via
Foramen rotundum, pterygoid canal (in the middle cranial fossa) - Nasopharynx
- Palatovaginal canal - Roof of oral cavity (palate)
Palatine canal
What are the contents of the pterygopalatine fossa and what is nearby but not in it which is clinically relevant
- CNV2
- Maxillary artery
- nerve of the pterygoid canal to the pterygoid (hayfever) ganglion
Near by on the other side of sphenoid is the internal carotid artery
What is the course of the maxillary artery and what are its branches in the pterygopalatine fossa.
what do the branches in the fossa accompany
- enters through the pterygomaxillary fissure
Branches - zygomatic artery
- posterior superior alveolar artery (goes through alveolar foramen on the mandible)
- infra-orbital artery
- anterior superior alveolar arteries
- Sphenopalatine artery - terminal part once it crosses sphenopalatine foramen related to posterior epistaxis
the branches accompany branches of the maxillary nerve and pterygopalatine ganglion
What is the course and major branches of the CNV2 maxillary nerve in the pterygopalatine fossa and beyond and what are they supplying sensation to
- Enters via the Foramen rotundum (middle cranial fossa)
Gives off branches
2.Zygomatic nerve (skin on face - Posterior superior alveolar nerve (upper molar teeth, adjacent buccal gingivae and maxillary sinus)
- From the pterygopalatine fossa CNV2 passes anteriorly through the inferior orbital fissure where it becomes the Infra-orbital nerve
infra-orbital nerve gives off branches
5. middle and 6. anterior superior alveolar nerves
(these innervate the upper teeth, maxillary sinus and nasal cavity)
What is the ganglion in the infratemporal fossa and what are the sympathetic and parasympathetic contributions: pre and post ganglion
+ function
Otic ganglion: medial side of CNV3 at foramen ovale
No sympathetic nerves synapsing at the ganglion - fibres from superior cervical ganglion go straight to parotid via auriculotemporal
Above the oral fissure
- pre: CN9 via lesser petrosal nerve
post: auricotemporal nerve to parotid to stimulate salivation
What is the difference between a greater palatine nerve block and a posterior superior alveolar nerve block for dental anaesthesia- nerve root, exit, innervation of what
Greater palatine nerve is a (branch of CNV2) exiting at the greater palatine foramen along the hard palate which innervate the mucosa and glands of the hard palate and adjacent gingiva almost as far forward as incisors
Posterior superior alveolar nerve is also from CNV2. It exits through a small alveolar foramen midway between the last molar tooth and inferior orbital fissure (top teeth)
It innervates the molar teeth, adjacent buccal gingivae and contributes to the supply of the maxillary sinus
What the venous drainage of the pterygopalatine fossa
Pterygoid plexus
What is the ganglion in the pterygopalatine fossa + clinical importance
Pterygopalatine ganglion: is important for the running nose and eyes so removal of this ganglion can relieve those symptoms
What are the sympathetic and parasympathetic contributions tp the Pterygopalatine ganglion:
pre and post ganglion
Preganglionic
Parasymp: CN7 via Greater petrosal nerve
Symp: Superior cervical sympathetic ganglion (T1)
to internal carotid plexus–> via
Deep petrosal nerve
Post ganglionic: symp + parasymp join fibres from the CNV2 to form 4 branches
(orbital, palatine, nasal and pharyngeal),
Other fibres pass superiorly to enter the main trunk of CNV2 and be distributed with
Posterior superior alveolar, infra orbital nerve, and
Zygomatic which has PG branches which innervate the lacrimal gland
What are the origin and insertion of the Medial pterygoid muscles (deep + superficial)
Medial:
Both from the Pyramidal process of palatine bone
1. Sup: + tuberosity of the maxilla
2. Deep: + Medial surface of the lateral plate of pterygoid process
to Medial surface of mandible near angle
