Temporal and Infratemporal Fossa Flashcards
What are the Boundaries of the Temporal Fossa?
- Posterior and superior
- Anterior
- Lateral
- Inferior
Posterior and superior: Temporal Lines
Anterior: Frontal and Zygomatic Bones
Lateral: Zygomatic Arch
Inferior:Infratemporal crest of the sphenoid
What are the contents of the Temporal Fossa?
- Temporalis Muscle and Fascia
- Deep Temporal Vessels and nerves
- Superficial temporal vessels
- Auriculotemporal nerve
What are the boundaries for the infratemporal Fossa? (Don’t really need to memorize it, it’s just for knowledge)
Anterior: Posterior aspect of maxilla
Medial: Lateral Pterygoid plate
Lateral: Ramus of the mandible
Superior: Inferior surface of the greater wing of the sphenoid
posterior: The tympanic plate and the mastoid and styloid processes of the temporal bone
inferior: Site of attachment of the medial pterygoid to the mandible near its angle
What type of joint is the Temporomandibular joint?
A synovial joint; modified hinge joint
What articulates with the temporomandibular joint?
- Mandibular condyle
2. Mandibular fossa and articular tubercle of the temporal bone
What is an articular disc composed of?
fibrocartilage
what are the compartments that the articular disc divides the temporomandibular joint into?
- superior compartment- responsible for gliding movement of protrusion and retrusion
- inferior compartment- responsible for hinge movement of depression and elevation
What does the superior compartment of the temporomandibular joint responsible for?
Gliding movement of protrusion nd retrusion
What does the inferior compartment of the temporomandibular joint responsible for?
hinge movement of elevation and depression
What is the articular disc peripherally attached to?
the joint capsule
What is te articular disc anteromedially attached to?
the tendon of the lateral pterygoid
What does the articular capsule of the temporomandibular joint attach to superiorly?
to the articular tubercle and the margins of the mandibular fossa
What does the articular capsule of the temporomandibular joint attach to inferiorly?
to the neck of the mandible
What type of membrane lines above and below the articular disc of the temporomandibular joint?
Synovial membrane
Does the synovial membrane cover the articular disc of the Temporomandibular joint?
NO
Name all three ligaments that are associated with the temporomandibular joint?
Temporomandibular ligament (Lateral Ligament)
Stylomandibular ligament
Sphenomandibular ligament
What is another name of the lateral ligament?
Temporomandibular ligament
What does the stylomandibular ligament attach to?
Styloid process and the angle of the mandible
What does the sphenomandibular ligament attach to?
Spine of the sphenoid and the lingula of the mandible
What are the four muscles of mastication?
- Temporalis
- Masseter
- Medial pterygoid
- Lateral Pterygoid
What nerve innervate the muscles of mastication?
innervated by branches of V3 (Mandibular branch of the trigeminal nerve)
What is the origin of the temporalis?
inferior temporal line, temporal fossa, and temporalis fascia
Where is the Temporalis inserted?
Coronoid process and anterior surface of the ramus of the mandible
What innervate the Temporalis muscle?
Anterior and posterior deep temporal nerves
What are the actions of the Temporalis muscle? (3)
- Elevation of mandible (Closes mouth)
- Retrusion of mandible
- Right and left lateral movement (grinding and chewing)
What is the origin of the masseter?
Inferior border and medial surface of the maxillary process of zygomatic bone and the zygomatic arch
Where is the Masseter muscle inserted?
Angle and lateral surface of the mandible
What innervate the masseter muscle?
Masseteric nerve
What are the actions of the Masseter muscle? (4)
- Elevation of the mandible
- Right and left lateral movement
- protrusion of the mandible
- retrusion of the mandible
What is the origin of the Lateral Pterygoid Muscle?
Superior head- infratemporal surface of the greater wing
inferior heard- lateral surface of the lateral pterygoid plate
Where is the Lateral Pterygoid muscle inserted?
most fibers insert on the pterygoid fovea on the anterior surface of the neck of the mandible; some fibers from the superior head insert on the joint capsule and articular disc of the temporomandibular joint.
What innervate the Lateral pterygoid muscle?
Lateral Pterygoid nerves
What are the actions of the Lateral Pterygoid muscle? (3)
- Protrusion of the mandible
- depresses mandible
- Right and left lateral chewing and grinding movements
What is the origin of the Medial Pterygoid Muscle?
Deep Head- medial surface of lateral pterygoid plate
superficial head- tuberosity of maxilla
What is the insertion of the Medial Pterygoid?
Medial surface and angle of mandible
What is the innervation of the Medial Pterygoid?
Medial Pterygoid nerve
What are the Actions of the Medial Pterygoid muscle? (3)
- Elevation of mandible
- Protrusion of mandible
- Right and Left lateral chewing and grinding movement
What does Excessive contraction of the Lateral pterygoid can cause?
It can cause the heads of the mandible to dislocate anteriorly past the articular tubercle
what can lead to the mandible to stay open and the person to be unable to close it?
excessive contraction of the lateral pterygoid which causes the heads of the mandible to dislocate anteriorly past the articular tubercle
Why is posterior dislocation of the mandible is uncommon?
Due tot he presence of the postglenoid tubercle and the strong lateral ligament
What will Falls in the chin or a direct blow to the chin can most often cause?
it will cause the neck of the mandible to fracture before posterior dislocation occurs.
How is Reduction of the anterior dislocated mandible performed?
by pressing downward on the last molar teeth
Communications with the infratemporal fossa
- Temporal fossa through the space between the zygomatic arch and cranial wall
- The orbit through the inferior orbital fissure
- The middle cranial fossa through the foramen ovale and foramen spinosum
- Pterygopalatine fossa via the pterygomaxillary fissure
Contents of the infratemporal fossa (6)
- Medial and lateral pterygoid muscles
- Mandibular divions of V (V3)
- Otic ganglion
- Chorda Tympani
- Maxillary artery and its branches
- maxillary vein and pterygoid venous plexus