Infratemporal Fossa Pt. 1 Flashcards
An irregularly-shaped space in the head that is surrounded by bone and soft tissues
Infratemporal fossa
The infratemporal fossa contains structures that are important for
Mastication, taste, and salivation
The infratemporal fossa is inferior to the
Zygomatic arch
The infratemporal fossa is deep/medial to the
Ramus of the mandible
The infratemporal fossa is lateral to the
Sphenoids lateral pterygoid plate
The infratemporal fossa is posterior to the
Maxilla
One of the regions where anesthesia may be administered by dentists for nerve blocks during work on mandibular teeth
Infratemporal fossa
Superior to the zygomatic arch and communicates with the infratemporal fossa through a gap between the zygomatic arch and cranial bones
Temporal fossa
The floor of the temporal fossa is formed by the
Sphenoid (gretaer wing), temporal (squamous portion), frontal, and parietal bones
The sutures that unite these bones forms the
H-shaped pterion
Fully occupies the temporal fossa and extends into the infratemporal fossa
-one of the four muscles of mastication
Fan-shaped temporalis muscle
Covers the temporalis and attaches to the zygomatic arch to provide resistance to the masseter that pulls down on the zygomatic arch
Tough facia
Located intracranially and medially to the infratemporal fossa
Middle cranial fossa
The Middle cranial fossa communicates with the infratemporal fossa through the
Foramen ovale and foramen spinosum
Openings in the intervening greater wing of the sphenoid bone that transmit neurovasculature
Foramen ovale and Foramen spinosum
The largest of three major paired salivary glands
-located in the posteriolateral part of the face
Parotid gland
Wedged within a region bounded by the zygomatic
arch (superiorly), external acoustic meatus-mastoid process-sternocleidomastoid (posteriorly), mandible ramus and masseter (anteromedially)
Parotid gland
Course through the parotid region
External carotid artery and retromandibular vein
Proceeds anteriorly and horizontally from the gland and turns medially at the masseters anterior border to pierce the buccinator
Parotid duct
The parotid duct pierces the buccinator and enters the oral cavity through an orifice located near the
2nd maxillary molar tooth
Course through the parotid gland on their way to supply the muscles of facial expression
Somatic motor branches of CN VII
The parotid gland and some lymph nodes are enclosed in a tough, unyielding fascia capsule known as the parotid sheath, which forms from the
Inversting layer of deep cervical fascia
Mumps virus may result in parotid gland inflammation known as
Paroditis
Swelling within the parotid sheath can cause pain during chewing and in the auricle and external aucoustic meatus that is relayed by
1.) Auriculotemporal nerve of CN V3, and the great auricular nerves (C2-C3)
Somatic (branchial) motor fibers of the facial nerve (CN VII), which course through the parotid gland, may
be injured from parotiditis or surgery and result in
Facial nerve (Bell’s) palsy
Facial nerve (Bel’s) palsy results in weakness or paralysis of
Facial muscles on ipsilateral side
Eversion of inferior eyelid, dry eye, tearing, impaired pronunciation of B, M, P, or W, and inability to whistle are symptoms of
CN VII (Bell’s) Palsy
In Bell’s palsy, the skin of the affected side may show
Irritation
Anterior and medial to the infratemporal fossa, with separation by muscles and mucosa
Oral cavity
Deep and medial to the infratemporal fossa
Pterygopalatine fossa
Allows passage of neurovascular structures between the infratemporal fossa and pterygopalatine fossa
Pterygomaxillary fissure
The parotid, temporal, and infratemporal regions include the
Tempromandibular joint (TMJ)
What produces the movement of the TMJ?
Muscles of mastication
What are the four muscles of mastication?
Temporalis, masseter, lateral pterygoid, and medial pterygoid
Which of the four muscles of mastication are located in the infratemporal fossa?
Inferior part of temporalis and the lateral and medial pterygoid
The superior part of the temporalis is located in the
Temporal fossa
The masseter is located
Lateral to the ramus of the mandible
-outisde of infratemporal fossa
The muscles of mastication, tensor muscles, and some suprahyoid muscles are all derivatives of the first pharyngeal arch and are innervated by branches of the
Mandibular nerve (CN V3) which is located in the infratemporal fossa
At the superior end of the jaw, immediately anterior to the ear/external acoustic meatus
Tempromandibular joint (TMJ)
In the TMJ, the temporal’s madibular fossa receives the head of the
Condylar/condyloid process of the mandible
The mandibular fossa is bound anteriorly by the
Articular tubercle
The mandibular fossa is bound posteriorly by the
Postglenoid tubercle
articular disc of the TMJ interposed between bones to create two separate joint cavities/spaces
Fibrocartilaginous meniscus
Surrounds the TMJ and attaches to the temporal bone, neck of mandible’s condylar process, and the peripheral edges of the articular disc
Fibrous joint capsule
The attachment of the edges of the articular disc
to the internal aspects of the capsule separates the articular surfaces and creates two separate (superior and inferior) joint cavities that are lined by
Synovial membranes
Several types of mandibular movements are possible at the TMJ because it has
2 joint cavities
What type of movements occur in the superior joint cavity>
Gliding movements (translation)
The gliding movements of the mandible in the superior joint cavity allow themandible to
- ) Protrude/protract anteriorly
2. ) Retrude/retract posteriorly
These gliding movements occur as the articular disc and condylar head glide together along the mandibular fossa up to the
Articular tubercle
The prime mover in protrusion
Lateral pterygoid
Prime mover in retrusion
Horizontal fibers of the temporalis
What are the two types of movements that occur in the inferior joint cavity?
- ) Hinge movements (elevation/depression)
2. ) Rotation/spin along a vertical axis (lateral movements in grinding)
When the mouth closes, what happens to the mandible?
Retracts and elevates
When in a deep sleep, there is tonic contraction of retractor muscles and relaxation of elevator muscles causing
Mouth to open slightly
For the mouth to open wide, the mandible is
Protruded and depressed
The prime mover in depression of the mandible
Gravity
Help depress the mandible against resistance
Platysma, suprahyoids, infrahyoids, and lateral pterygoid
When one condyle of the mandable spins/rotates around a vertical axis and the contralateral condyle translates forward, we get a small degree of
Lateral movement of the mandible
The lateral movements for grinding and chewing occure through the action of the
Masseter and temporalis of the same side and the pterygoids of the opposite side
When protraction of the head and disc occurs unilaterally, the contralateral, retracted head rotates (pivots) on the inferior surface of the articular disc, permitting simple
Side-to-side grinding
Sometimes during yawning or taking a large bite, excessive contraction of the lateral pterygoid may
cause the disc with heads of the mandible to cross the anterior tubercle of the TMJ, causing
TMJ dislocation (can’t close mouth)
-lock-jaw
What resists posterior dislocation of the TMJ?
Postglenoid tubercle and ligaments
Blows to the chin often result ina fracture of the
Neck of themandible
Fracture of the mandibular condyle results in a unilateral lateral pterygoid function in which there is deviation of the jaw to the
Affected side
The terminal branches of the external carotid artery are the
Superficial temporal and maxillary arteries
The temporalis muscle is supplied by the
Superficial temporal artery and some muscular branches of the maxillary artery
Originates within the parotid gland, near the neck of the mandible
Maxillary artery
The maxillary artery enters the infratemporal fossa either lateral to or within the
Lateral pterygoid muscle
Branches of the maxillary artery supply the
Dura matter of cranial cavity, nasal cavity, oral cavity, and all teeth
The maxillary artery is divided into which three parts based on its relation to the lateral pterygoid muscle in the infratemporal fossa?
- ) Mandibular part
- ) Pterygoid part
- ) Pterygopalatine part
Deep to the condyle of the mandible
-branches into middle meningeal artery and inferior alveolar artery
Mandibular (1st) part of maxillary artery
Exits the infratemporal fossa by ascending vertically via the foramen spinosum to reach the middle cranial fossa of the cranial cavity to supply the dura and bone
Meningeal artery
Passes between the two roots of the auriculotemporal nerve in the infratemporal fossa
Meningeal artery
Travels with the inferior alveolar nerve of CN V3, descends to exit the infratemporal fossa via the mandibular foramen
Inferior Alveolar Artery
The inferior alveolar artery eventually becomes the
Mental Artery (supplies the chin)
Located lateral to or within the lateral pterygoid muscle
Pterygoid (2nd) part of maxillary artery
Gives off numerous branches to the muscles of mastication
Pterygoid (2nd) part of maxillary artery
Passes through pterygomaxillary fissue to exit from the infratemporal fossa and enter into the pterygopalatine fossa
Pterygopalatine (3rd) part of maxillary artery
The pterygopalatine part of the maxillary artery branches into the
- ) Posterior superior alveolar artery
- ) Infraorbital artery
- ) Sphenopalatine artery
Supplies maxillary teeth
Posterior superior alveolar artery
Supplies part of the cheek
Infraorbital artery
Supplies the nasal cavity
Sphenopalatine artery
Lies between the temporalis and lateral pterygoid muscle in the infratemporal fossa
-Venous sequivalent of the maxillary artery
Pterygoid venous plexus
The pterygoid venous plexus communicates anteriorly with the
Facial vein via Deep facial vein
The ptrerygoid venous plexus communicates superiorly with the
Cavernous sinus (via emissary veins)
The pterygoid venous plexus also has an indirect communication with the
Inferior opthalmic vein
The pterygoid venous plexus also communicates
with the external jugular vein via the
Maxillary and retromandibular veins
