Infratemporal Fossa and TMJ Flashcards
What is the infratemporal fossa?
Space beneath the base of the skull between the skull and the ramus of the mandible
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 the mandible
What is the contents of the infratemoral fossa?
Lateral and medial pterygoid, Mandibular division of trigeminal and branches, Maxillarty artery and branches, Pterygoid venous plexus, Chorda tympani and Otic ganglion
What is the function of the medial pterygoid?
Assists in elevating the mandible
What is the function of the Lateral pterygoid?
Pulls the neck of the mandible forward
What movements does both the medial and lateral pterygoid give?
Chewing movements
What innervates the medial and lateral pterygoid?
Mandibular division of CN V
What divisions does the mandibular division of trigeminal nerve have?
Anterior and posterior divisions
What are the anterior divisions of the mandibular division of CN V?
x2 deep temporal, masseteric nerve to lateral pterygoid, buccal (sensory)
What are the posterior divisions of the mandibular division of CN V?
Lingual (joined by chords tympani), inferior alveolar, mylohyoid and auricultemporal
What is the passage of the maxillary artery?
Passes between 2 heads of lateral pterygoid to go into ptergomaxillary fissure - fossa and give off posterior superior alveolar branch
What are the pre divisions of the mandibular division of CN V?
Meningeal, nerve to medial ptertgoid and communicating branch
What is the communicating branch in the pre divisions of mandibular division of CN V?
Tensor tympani and tensor velo palatini
What are the branches of the Maxillary artery?
Deep temporal, masseteric and pterygoid branched to muscles
What are the 3 parts of the maxillary artery?
Mandibular, pterygoid and pterygopalatine
What are the Pterygopalatine branches?
Posterior superior alveolar, Infraorbital, anterior superior alveolar branches and palatine, pharyngeal and sphenopalatine branches.
What does the pterygoid venous plexus surround?
Lateral pterygoid
Where are the veins of the pterygoid venous plexus from?
Orbit, nasal and oral cavities
What does the pterygoid venous plexus communicate with?
Cavernous sinus and facial vein
What drains the pterygoid venous plexus?
Maxillary vein
What is the route for infection?
Pterygoid venous plexus
What is involved in the posterior superior alveolar branch?
Upper molar and premolar
What is involved in the infraorbital branch?
Canal in floor of orbit, foramen
What is involved in the anterior superior alveolar branch?
Upper incisor and canine
Has the otic ganglion have a synapse?
No
What goes through the otic ganglion?
Postganglionic sympathetic fibres and motor neves to tensor tympani and tensor veli palatine (CN VIII)
What happened at the foramen oval?
Has the mandibular division
What joint in the temporomandibular joint (TMJ)?
Synovial joint
Where is the TMJ?
Between the head of mandible and mandibular fossa and articular tubercle on the squamous part of the temporal bone?
What type of cartilage covers the articular surfaces of TMJ?
Fibrocartilage (membranous ossification)
What is the nerve supply of the TMJ?
Auriculotemporal and masseteric
What reinforces the TMJ capsule?
Lateral (temporomandibular) ligament
What supports the TMJ medially?
Sphenomandibular and stylomandibular ligaments
What dos the lateral pterygoid attach to?
Articular disc and capsule
What is the cavity of TMJ divided by?
Fibrous articular disc
What does the TMJ disc increase?
Congruity of articular surfaces
What movements does the head of mandible and disc?
Elevation and depression (hinge)
What gives protrusion and retraction (gliding) in the TMJ?
Disc and mandibular fossa and articular process
What movements close the mouth?
Elevation and retraction pull condyle backwards
What movements open the mouth?
Both sides depression and protrusion to slide disc and condyle forwards towards tubercle
What is the movement of chewing called?
Asynchronous gliding
Describe elevation of the mandible?
Head of mandible and disc move backward and head rotated on lower surface of disc
What muscles aid in elevation the mandible?
Temporalis, masseter and medial pterygoid
Describe depression of the mandible?
Hey of mandible rotates on undersurface of articular disc and mandible is pulled forward
What muscles aid in depression of the mandible?
Lateral pterygoid, digastric, geniohyoid, mylohyoid and gravity
Describe protrusion of the mandible?
Articular disc and head of mandible move forward
What muscles aid in protrusion of the mandible?
Lateral pterygoid
Describe retrusion of the mandible?
Articular disc and head of mandible pulled backwards into mandibular fossa
What muscles aid in retrusion of the mandible?
Posterior fibres of temporalis
