(20) Deep Face & Temporal Region

Pterion

Junction of frontal, parietal, sphenoid (greater wing), and temporal (squamous part) bones

zygomatic arch

zygomatic bone & zygomatic process of temporal bone. Serves as the boundary between the temporal fossa & infratemporal fossa

temporal fossa

Space anterior to the zygomatic arch that largely contains the temporalis muscle. Formed by the frontal, parietal, sphenoid (greater wing), and temporal (squamous part) bones. Communicates freely with the infratemporal fossa.

infratemporal fossa

Space posterior to the zygomatic arch & deep to mandible between the maxilla and lateral pterygoid plate that goes to the deep face & out through the nasal cavity. Communicates freely with temporal fossa.

contents of infratemporal fossa

-Medial and lateral pterygoid muscles

-Maxillary artery and its branches

-Branches of V3

-Facial nerve branches

-Lesser petrosal nerve (branch of glossopharyngeal nerve)

-Otic ganglion

lateral pterygoid plate

sharp process that laterally and inferiorly projects from the sphenoid & is the floor of the infratemporal fossa.

inferior orbital fissure

opening in the orbit floor between maxilla and greater wing of sphenoid

Pterygomaxillary fissure

triangular opening between lateral pterygoid plate and maxilla

Pterygopalatine Fossa

space inside the pterygomaxillary fissure

Sphenopalatine foramen

hole in the lateral wall of each nasal cavity within the pterygopalatine fossa that allows the passage of branches of the maxillary artery

Optic Canal is located in

lesser wing of sphenoid

foramen rotundum, spinosum, & ovale are located in

greater wing of sphenoid

superior orbital fissure is located

between the greater and lesser wings of the sphenoid bone

lateral plate of pterygoid process

more lateral projection of the pterygoid process of the sphenoid

medial plate of pterygoid process

more medial projection of the pterygoid process of the sphenoid

pathway of maxillary artery

infratemporal fossa, through pterygomaxillary fissure, pterygopalatine fossa, through sphenopalatine foramen, nasal cavity

angle of mandible

meeting point of the body & ramus

coronoid process of mandible

beak-like anterior projection of mandible that allows attachment for temporalis muscle

condyle/head of mandible

rounded anterior projection of mandible that forms the hinge between the maxilla and the mandible and is a part of the temporomandibular joint

neck of mandible

the constricted portion just inferior to the mandibular head

mandibular notch

between coronoid process and mandibular condyle

alveolar process of mandible

bumpy, ridge-like projections where the bottom teeth are held

lingula of mandible

tongue-like process that serves as the site for attachment of sphenomandibular ligament, which restricts some movement

mandibular foramen

Hole on the medial surface of the ramus that allows passage of inferior alveolar nerve & vessels into the mandibular canal

Temporomandibular Joint (TMJ)

modified synovial hinge joint with high mobility between the temporal bone and the condyle of the mandible that enables chewing movements of the jaw

articular tubercle

convexity in front of the condyle that limits and controls mandibular movement at the TMJ

mandibular/glenoid fossa

the depression in the temporal bone into which the condyle of the mandible fits at the TMJ

articular disc of TMJ

divides synovial cavity of TMJ into superior and inferior chambers

joint capsule

The fibrous sac that keep a joint together

Ligaments of the TMJ joint

lateral ligament, sphenomandibular ligament, stylomandibular ligament. All function to restrict jaw opening.

lateral ligament of TMJ

reinforces TMJ joint capsule

sphenomandibular ligament

ligament running from the sphenoid bone to the lingua of the mandible

stylomandibular ligament

ligament running from the styloid process to the angle of the mandible

3 Planes of TMJ movement

1. Anterior/Posterior aka Protraction/Retraction

2. Superior/Inferior

3. Medial and Lateral

protraction of mandible

Bringing the lower jaw forward/anterior

retraction of mandible

Bringing the lower jaw backward/posterio

Rotation of Condyle

hinge movement in the inferior synovial cavity, resulting in slight depression of the mandible

protraction of condyle

gliding movement in the superior synovial cavity between articular disk and mandibular fossa

slight jaw opening requires

rotation of mandibular condyle only

wide jaw opening requires

both rotation & protraction of mandibular condyle only

Muscles of mastication

temporalis, masseter, medial pterygoid, lateral pterygoid

-All are innervated by the mandibular division of the trigeminal nerve (V3)

-Most function as jaw closers

Temporalis

two-fibered muscle of mastication that originates in the Temporal Fossa & inserts on the Coronoid process of the mandible

-Functions to close/elevate the jaw, & to retract the jaw

Masseter

muscle of mastication that originates in the zygomatic arch & inserts on the lateral side of the mandibular ramus & angle

-Function to close/elevate the jaw, & to protract the jaw

medial pterygoid

muscle of mastication that originates on the medial side of the lateral pterygoid plate & inserts on the medial side of the mandibular ramus & angle

-Functions to close/elevate the jaw, to protract the jaw, & (unilaterally) to move the jaw to the contralateral side

lateral pterygoid

muscle of mastication with 2 heads. The superior head originates in the greater wing of sphenoid, & inserts on the articular disk/capsule of TMJ. The inferior head originates in the lateral side of lateral pterygoid plate of sphenoid & inserts on the neck of the mandible.

-Functions to open the jaw & depress the chin by pulling the condyle anteriorly, to protract the jaw, & (unilaterally) to move the jaw to the contralateral side

foramen ovale

opening in the sphenoid bone through which V3 exits

foramen spinosum

opening in the sphenoid bone through which the middle meningeal artery enters the head

V3 nerve branches of the infratemporal fossa

1. Deep temporal nerves

2. Nerve to mylohyoid

3. Auriculotemporal nerve

4. Buccal Nerve

5. Lingual Nerve

6. Mental Nerve

7. Inferior alveolar nerve

Deep temporal nerve

branch of V3 that provides somatic motor innervation to the temporalis muscle

nerve to mylohyoid

branch of V3 that provides somatic motor innervation to the mylohyoid & the anterior belly of the digastric

-closely associated with inferior alveolar nerve

Auriculotemporal nerve

branch of V3 that provides somatic sensory innervation to the TMJ, side of head & scalp, & anterior ear

-Posterior to superficial temporal artery

-Forms a loop over the middle meningeal artery in many cases

-Relays postganglionic parasympathetic fibers of CN IX to the parotid gland

buccal nerve

branch of V3 that provides somatic sensory innervation to the skin over the cheek

lingual nerve

branch of V3 that provides somatic sensory innervation to the anterior 2/3rd of the tongue & the mucosa of the floor of the mouth

-anterior to inferior alveolar nerve

-passes inferior to Lateral pterygoid muscle & crosses medial pterygoid muscle

mental nerve

branch of V3 that provides somatic sensory innervation to the chin & lower lip

-Fully continuous with inferior alveolar nerve; name change happens after it passes out of the mental foramen

inferior alveolar nerve

branch of V3 that provides somatic sensory innervation to the lower teeth & gums

-Posterior to lingual nerve

-passes inferior to Lateral pterygoid muscle & crosses medial pterygoid muscle

Branches of the facial nerve in petrous temporal bone (after it leaves brainstem & enters internal acoustic meatus)

1. Greater petrosal nerve

2. Branch to muscles of facial expression

3. Chorda Tympani

greater petrosal nerve

branch of the facial nerve after the geniculate ganglion that carries parasympathetics & taste innervation

branch to muscles of facial expression

branch of the facial nerve that exits the stylomastoid foramen & carries somatic motor innervation to the muscles of facial expression

chorda tympani

branch of the facial nerve that carries the special sense of taste to anterior ⅔ of tongue & preganglionic parasympathetics to the submandibular and sublingual glands

pathway of chorda tympani

branches off facial nerve in petrous temporal bone → crosses tympanic cavity and tympanic membrane over malleus → exits tympanic cavity to infratemporal fossa → enters infratemporal fossa to travel with lingual nerve to the submandibular ganglion & the tongue

Cranial Nerves in Infratemporal Fossa

CNV3, CN VII, CN IX

lesser petrosal nerve

Branch of the glossopharyngeal nerve (CN IX) that supplies parasympathetic fibers for the parotid gland, which synapse in the otic ganglion before being relayed by the auriculotemporal nerve.

Mandibular nerve block

Injection of anesthetic at V3 as it exists foramen ovale. Numbs Inferior alveolar nerve (lower teeth), Mental nerve (skin over chin), & Lingual nerve (tongue)

maxillary artery

one of the terminal branches of the external carotid artery that branches & supplies blood within the infratemporal fossa. Also supplies masseter, buccinator, & pterygoids.

Branches of maxillary artery

1. Deep Temporal Arteries

2. Infraorbital artery

3. Posterior superior alveolar arteries

4. Inferior alveolar artery

5. Middle meningeal artery

6. Sphenopalatine artery

7. Descending palatine artery

deep temporal arteries

branches of the maxillary artery that supply temporalis muscle

infraorbital artery

Branch of the maxillary artery that runs through the inferior orbital fissure, through the infraorbital canal, & then through the infraorbital foramen to supply blood to the muscles of the eye

posterior superior alveolar arteries

branches of the maxillary artery that supply the upper teeth

inferior alveolar artery

branch of the maxillary artery that supplies the lower teeth

middle meningeal artery

branch of the maxillary artery that enters the skull through foramen spinosum & supplies the dura mater of the cranial cavity.

Sphenopalatine artery

branch of the maxillary artery that supplies the nasal cavity

Descending palatine artery

Deepest branch of the maxillary artery that supplies the palate