Temporal and Infratemporal Fossa Flashcards
what is the temporal fossa?
lateral area of skull overlying squamous portions of frontal, parietal temporal and sphenoid bones
this region is continuous inferiorly with the infratemporal fossa
what are the boundaries of the temporal fossa?
anterior/superior/posterior border?
inferior (lateral)?
superior temporal line (zygomatic, frontal, parietal, temporal bones)
inferior (lateral)–> zygomatic arch
inferior (medial) –> infratemporal crest of temporal and sphenoid bones
what are the contents of the temporal fossa?
upper portion of temporalis muscle and a dense temporalis fascia
what is the infratemporal fossa?
deep region of head lying inferior and deep (inferiomedial) to temporal region
lateral abounder of ITF
ramus of mandible
superior (lateral)
superior (medial) borders of ITF
zygomatic arch (lateral) infratemporal crest of temporal and sphenoid bones (medial)
medial border of ITF
lateral pterygoid plate of sphenoid and pharynx
anterior border of ITF
maxilla
poseterior border of ITF
imaginary line connecting posterior border of ramus of mandible and styloid process of temporal bone
inferior border of ITF
continuous with submandibular region
what are the general contents of the ITF
which muscles? arteries? veins? nerves? ganglion?
- Lower portion of temporalis muscle
- Medial pterygoid2
- Lateral pterygoid
- Maxillary artery (1st and 2nd portion)
- Pterygoid plexus of veins
- Mandibular division of CN V (V3)
- Otic ganglion
what is the TMJ
what type of tissue is inside the joint.
temporomandibular joint
articulation b/w mandible (condyle) and temporal bone (mandibular fossa and articular tubercle)
containts a dense connective tissue articular disc which separates the joint into two separate synovial lined cavities
during chewing what happens to the joint?
operates during chewing: while opening the mouth, the condyle of the mandible slides anteriorly against the posterior surface of the articular tubercle
what is the joint capsule ?
loose covering above the disc and tight below the disc
what are the 3 ligaments of the TMJ?
lateral ligament of TMJ
stylomandibular
sphenomandibular
lateral ligament of TMJ
thickening of joint capsule
helps to prevent posterior dislocation of mandible
stylomandibular ligament
thickening of parotid fascia
extends from styloid process to angle of mandible
not a very strong ligament
sphenomandibular ligament
extends from spine of sphenoid to lingula of mandible
strong ligament, provides most passive support for TMJ
what type of joint is the TMJ ?
synovial joint
what type of motion is in the upper TMJ
what movements of the jaw does this part allow
- Upper portion (between temporal bone and disc)
a. Gliding movements
b. Allows for protrusion/retrusion and elevation/depression of mandible
what type of motion is in the lower portion of the TMJ
what type of jaw motions does this allow?
- Lower portion (between disc and mandible)
a. Pivot-type movements
b. Allows for side-to-side movements during chewing.
what occurs in dislocation of the TMJ?
how can this be corrected
what other structures can be damaged by this ?
- Mandibular condyle slides too far anteriorly (anterior to the articular tubercle) and results in inability to close the jaw.
- Mandible must be pushed inferiorly and then posteriorly to correct the dislocation.
- Dislocation may damage the auriculotemporal nerve.
what is a cause of crepitus (clicking) or popping while opening the jaw
TMJ can develop arthritis leading to degeneration of the cartilage and bones of the joint
painful
from what embryologic arch are the muscles of mastication derived?
what are they innervated by?
function?
from the 1st pharyngeal arch
V3
function- mastication
attachments of the temporalis muscle
- Origin – temporal lines and deep temporal fascia / infratemporal crest
- Insertion – coronoid process and anterior surface of ramus of mandible
function of temporalis
elevates (closes) and retracts jaw
innervation of temporalis
V3 via anterior and posterior deep temporal nn.
what is the temporobuccinator band? function?
a. Dense fascial band that spans from temporalis tendon to buccinator muscle. Contracts when temporalis contracts
b. Function – pull buccinator muscle away from teeth.
Masseter attachments
- Origin – zygomatic arch (maxilla and zygomatic bone)
2. Insertion – external surface of ramus of mandible