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
masseter function and innervation
- Function – elevates (closes) mandible; assists with protrusion
- Innervation – V3 via masseteric branches
medial pterygoid attachments
- Origin – medial surface of lateral pterygoid plate (deep head); tuberosity of maxilla (superficial head)
- Insertion – internal surface of ramus of mandible
function and innervation of the medial pterygoid
elevates (closes) mandible and assists with protrusion and pivot movements of mandible (side to side movements during chewing)
lateral pterygoid attachments
- Origin – lateral surface of lateral pterygoid plate (deep head); infratemporal crest of sphenoid bone (superficial head)
- Insertion – neck of mandibular condyle (deep portion); articular disc (superficial; sphenomeniscal portion)
function and innervation of the lateral pterygoid
- Function – protrusion of mandible; acting unilateral, moves jaw towards contralateral side to produce pivot movements of chewing (side-to-side movement of jaw).
- Innervation – V3 via lateral pterygoid branch
what are the 3 portions of the maxillary artery?
mandibular
pterygoid
pterygopalatine
where does the maxillary artery course?
posterior to the neck of mandible (b/w it and the sphenomandibular ligament) to enter the infratemporal fossa
what is the maxillary artery a branch of?
terminal branch of the external carotid artery (superficial temporal artery is the other terminal branch)
where is the course of the mandibular portion of the maxillary artery?
courses deep to the neck of the mandible
what are the 5 branches off the mandibular portion of the maxillary artery
deep auricular anterior tympanic middle meningeal accessory meningeal inferior alveolar artery
deep auricular a.
external acoustic meatus, outer tympanic membrane, and TMJ.
anterior tympnanic artery
inner tympanic membrane (courses through petrotympanic fissure to reach middle ear).
middle meningeal artery
inner tympanic membrane (courses through petrotympanic fissure to reach middle ear).
accessory meningeal artery
enters middle cranial fossa via foramen ovale to supply dura and skull.
inferior alveolar artery
what other artery does it give rise to ?
enters mandibular foramen to supply mandible, mandibular teeth, and chin (via mental branch);
also gives rise to the mylohyoid artery prior to entering mandibular foramen. and mental artery
pterygoid portion of the pterygoid artery course?
courses through infratemporal region
either superficial or deep (50/50) to the lateral pterygoid muscle
what are the 5 branches of the pterygoid portion of the maxillary artery
a. Masseteric branches
b. Anterior and posterior deep temporal
c. Medial pterygoid branches
d. Lateral pterygoid branches
e. Buccal artery supplies cheek.
what is the course of the pterygopalatine portion of the pterygopalatine artery
- Courses through pterygomaxillary fissure to enter pterygopalatine fossa.
what are the 6 branches off the pterygopalatine portion of the maxillary artery
a. Posterior superior alveolar
b. Infraorbital a.
c. Pharyngeal a.
d. Artery of pterygoid canal
e. Descending palatine a.
f. Sphenopalatine a.
what is the pterygoid plexus of veins ? what muscle doe s it invest?
large venous plexus investing the external and internal surface of lateral pterygoid muscle
what does the pterygoid plexus of veins coalesce to form?
maxillary vein which then exits the infratemporal fossa travelling with the maxillary artery
the pterygoid plexus of veins receives blood from the infratemporal fossa and nasal cavity via what?
receives blood from the face via what?
receives blood from the cavernous sinus via what?
receives blood from the pharynx via what?
- Infratemporal fossa and nasal cavity via venae comitantes of maxillary artery
- Face via deep facial vein and ophthalmic veins
- Cavernous sinus via emissary veins
- Pharynx via pharyngeal veins
where does the mandibular nerve exit the middle cranial fossa?
via formane ovale to enter infratemporal fossa
what are the components of the Mandibular nerve and what do each of these components supply
GSA–> sensory to lower portion of the face, including chin, lower cheek, temporal region, mandibular teeth and gingivae, auricle and external acoustic meatus, floor of oral cavity, 2/3rds of tongue, dura of the middle cranial fossa
SVE- all muscles of 1st pharyngeal arch origin
what components does it distribute?
GVE-P from the CNVII and CNIX to the salivary glands
Distributes SVA fibers form CNVII to the anterior 2/3rds of the tongue
what are the muscles to which the trigeminal nerve (mandibular portion) supplies
muscles of mastication (temporalis, masseter, medial pterygoid, lateral pterygoid)
tensory tympani
tensor veli palatine
anterior belly of digastric
mylohyoid
what are the 4 sensory branches (GSA) of the mandibular nerve
meningeal
buccal
lingual
auriculotemporal
meningeal branch of V3
exits what foramen?
supplies what?
a. Re-enters middle cranial fossa via foramen spinosum
b. Supplies dura of middle cranial fossa
buccal nerve of V3
passes b/w what two muscles
pierces what and supplies what?
a. Exits the infratemporal region by passing between the two heads of the lateral pterygoid muscle
b. Pierces mucosa of cheek to supply cheek (internal and external), gingivae
where does the lingual nerve exits the infratemporal fossa (b/w what structures)
where does it travel
what does it supply?
what nerve joins the lingual nerve ?
a. Exits the infratemporal region by passing between the medial and lateral pterygoid muscles
b. Travels to oral cavity
c. Supplies the anterior 2/3rds of the tongue, floor of oral cavity, and mandibular gingivae with sensory innervation.
d. NOTE: Chorda tympani nerve (CN VII) joins the lingual nerve
what is the function of the chorda tympani joining the lingual nerve . what is it supplying and to what structures?
Chorda tympani nerve (CN VII) joins the lingual nerve in the infratemporal fossa to distribute taste (SVA) to the anterior 2/3rds of the tongue and GVE-P fibers to the submandibular and sublingual glands.
where does the auriculotemporal nerve arise from?
where does it exit the infratemporal fossa?
what does it provide and to what regions?
what autonomic portion and to what gland does this nerve distribute?
a. Arises from two roots which surround the middle meningeal artery.
b. Exits infratemporal fossa posteriorly by passing deep to neck of mandible.
c. Provides GSA to the TMJ, temporal region, auricle, external acoustic meatus, and external tympanic membrane.
d. NOTE: this nerve distributes GVE-P fibers to the parotid gland.
what are the 6 motor (SVE) branches of the mandibular nerve (V3)
- Medial pterygoid n
- Nerve to tensor tympani
- Nerve to tensor veli palatini
- Lateral pterygoid nn
- Masseteric nn
- Anterior and posterior deep temporal nn.
what branch of the mandibular nerve is the mixed branch and what are the components it carries? where does it course?
what are its branches (2) and what do they supply?
- Inferior alveolar n. (GSA and SVE)
a. Enters to the mandibular foramen to supply the mandibular teeth.
b. Branches
1. Mental n. –exits the mental foramen to supply the chin
- Mylohyoid n. (SVE) – supplies mylohyoid, anterior belly of digastric
mandibular nerve block?
needle passed through mandibular notch to inject anesthetic around main trunk of mandibular nerve.
inferior alveolar nerve block
a. Used primarily by dentists to anesthetize mandibular teeth.
b. Anesthetic is injected near the entrance of mandibular foramen.
where does the chorda tympani come off CN VII
in the middle ear
how does the lesser petrosal nerve exit the middle ear? where does it travel after it exits the middle ear
where does it synapse?
through the hiatus of lesser petrosal nerve and then courses through middle cranial fossa
synapses in the otic ganglion
where are the parasympathetic preganglionic cell bodies of nerves that are innervating submandibular and sublingual glands
salivatory nucleus in brainstem
where are parasympathetic preganglionic cell fibers traveling that innervate submandibular and sublingual glands
travel with CN VII via chorda tympani
where are parasympathetic postganglionic cell bodies for nerves that innevated submandibular and sublingual glands
submandibular ganglion
via what do parasympathetic postganglionic cell fibers that distribute to sublingual and submandibular run
lingual branch of V3
what two components is the chorda tympani carrying
SVA (taste) to the anterior 2/3rds of the tongue
GVE-P to the submandibular and sublingual glands
what is the function of parasympathetic innervation to the submandbiular and sublingual glands?
increase gland secretion
dysfunction of parasympathetic innervation to the submandibular and sublingual?
Xerostomia (dry mouth)
