Infratemporal Fossa and TMJ Flashcards
Describe depression of the mandible and the muscles involved
The head of the mandible rotates on the undersurface of the articular disc and the mandible is pulled forward
Lateral pterygoid, digastric, geniohyoid, mylohyoid and gravity
What is the chorda tympani?
A branch of the facial nerve
Carries afferent taste signals from anterior aspect of tongue
Joins the lingual nerve into the oral cavity
How does the mandibular division of the trigeminal (CN V3) nerve reach the infratemporal fossa?
Passes through the foramen ovale
What is the innervation of the medial and lateral pterygoids?
Mandibular division of Trigeminal nerve (CN V3)
Describe lateral chewing and the muscles involved
Protrusion and Retrusion combined
Pterygoid muscles
What divides the joint cavity of the TMJ?
Fibrous articular disc
What are the boundaries of the infratemporal fossa?
Anterior = posterior surface of the maxilla Posterior = styloid process Superior = infratemporal surface of the greater wing of sphenoid Medial = lateral pterygoid plate Lateral = ramus of mandible
Describe protrusion of the mandible and the muscles involved
Articular disc and the head of the mandible move forward. Movement is in the upper part of the cavity
Lateral pterygoid (medial pterygoid assists)
What is the infratemporal fossa?
Space beneath the base of the skull - between the skull and the ramus of the mandible
Between the heads of which muscles does the maxillary artery pass between?
The 2 heads of lateral pterygoid
What are the branches of the pterygopalatine branch of the maxillary artery?
Posterior superior alveolar Infraorbital Artery to the pterygoid canal Pharyngeal Palatine Sphenopalatine
What type of joint is the TMJ?
Synovial joint
Describe retrusion of the mandible and muscles involved
Articular disc and head of mandible are moved back into the mandibular fossa
Posterior fibres of temporalis
What is the contents of the infratemporal fossa? (6)
Lateral and Medial pterygoid Mandibular division of the trigeminal (CN V3) and branches Maxillary artery and branches Pterygoid venous plexus Chorda Tympani Otic ganglion
What does the pterygoid venous plexus communicate with?
Cavernous sinus and facial veins
This is a route for infection
What is the function of the disc of the TMJ
Increases the congruency of the articular surfaces
What are the 3 parts of the maxillary artery?
Mandibular
Pterygoid
Pterygopalatine
Describe elevation of the mandible and the muscles involved
The head of the mandible and the disc move backwards and the head rotates on the lower surface of the disc
Temporalis, Masseter, Medial Pterygoid
Where is the TMJ located?
Between the head of the mandible and mandibular fossa and articular tubercle on the squamous part of the temporal bone
What are the posterior divisions of the mandibular division of the Trigeminal nerve (CN V3)?
Lingual (which is joined by chorda tympani)
Inferior alveolar
Mylohyoid
Auriculotemporal
What strengthns the joint capsule of the TMJ?
Laterally by the Temporomandibular ligament
Medially by the Sphenomandibular and Stylomandibular ligament
What is the otic ganglion?
A parasympathetic ganglion located at the mouth of the foramen ovale in the infratemporal fossa.
It recieves parasympathetic fibres from glossopharyngeal nerve CN IX
Supplies secretomotor innervation to the parotid gland
What are the anterior divisions of the mandibular branch of trigeminal (CN V3)?
2x deep temporal
Masseteric
Nerve to lateral pterygoid
Buccal
