Infratemporal Fossa Flashcards
Innervation of TMJ
1) Auriculotemporal 2) masseteric n.
Infratemporal Fossa boundaries
inferior to zygomatic arch inferior to greater wing of sphenoid deep to ramus of mandible lateral to pterygoid process or sphenoid posterior to tubercule of maxilla (3rd molar) Anterior to mastoid process and styloid process
What is superior lateral pterygoid attached to in the TMJ?
Squamotympanic fissure and articular disc
TMJ articular disc
dense and fibrous, but not firbrocartilage convex upp and concave lower Peripheral annulus with central depression (like an inner-tube with thin are in center) Upper elastic posterior lamina Lower-Non-elastic posterior lamina that attaches with joint capsule
trituration
side to side movement of jaw
what parts of TMJ are covered in fibrocartilage?
Articular emience, condyle of mandible
Lateral temporomandibular lig
post-lateral thickening stablizes lateral aspect of joint and prevents post displacement
Jaws in humans vs chimps
we have shorter jaws which allow us to have more leverage and smaller teeth
Lateral Pterygoid Superior head vs inferior head
Superior head pulls disc anteriorly, while the inferior pulls the mandible.
Elevation:
temporalis, masseter, medial pterygoid
What is the movement of jaw opening
slight hinge, gliding/displacement, then hinge.
what ligament is continuous with the sphenomandibular?
anterior malleolar lig. continuous with the ear and can cause someone to go deaf if they dislocate their jaw
Characteristics of TMJ capsule
loose upper fibers, tight lower fibers
Depression of jaw
relaxation is mostly by gravity. digastric, geniohyoid, and mylohyoid do active depression
Protrusion of jaw
lateral pterygoid , masseter
Retraction
Temporalis masseter,
Joint capsular attachments
Edge of articular fossa (glonoid fossa), squamotympanic fissure, neck of mandible, circumference of articular disc
what is the name of the cartilage on the TMJ?
fibrocartilage
TMJ compartments
upper gliding lower hinge
How does the TMJ disc return after protrusion?
The lamina has a lot of elastic fibers that pull it back in the direction of the head of the mandible
Grinding
medial and lateral pterygoid
What is involved in jaw closing
Posterior temporalis m.
What ligament prevents the lateral and posterior displacement of the TMJ?
Lateral temprormandibular lig
Sphenomandibular Ligament
Spine of sphenoid to lingula of mandible. stabalzes axis of rotation (right to left)
