Temporal and Infratemporal Regions

Temporal Fossa - Temple Territory

• Boundaries:
  • Superior & Posterior: Superior temporal line.
  • Anterior: Frontal & zygomatic bones.
  • Lateral: Zygomatic arch.
  • Inferior: Infratemporal crest (greater wing of sphenoid).
  • Floor: Pterion (junction of Frontal, Parietal, Temporal, Sphenoid bones 📌FPTS).
  • Roof: Temporal fascia (superficial layer).
• Contents:
  • Temporalis muscle.
  • Temporal fascia (deep layer, investing temporalis m.).
  • Deep temporal nerves (anterior & posterior branches of mandibular nerve V3).
  • Deep temporal arteries (anterior & posterior; from maxillary artery) & accompanying veins.

⭐ Pterion: key floor landmark; overlies middle meningeal artery. Fracture risks epidural hematoma.

Infratemporal Fossa - Deep Skull Base

• Irregular space inferior & deep to zygomatic arch.
• Boundaries:
  • Lateral: Mandibular ramus.
  • Medial: Lat. pterygoid plate.
  • Anterior: Post. maxilla.
  • Posterior: Tympanic plate, styloid/mastoid.
  • Roof: Sphenoid greater wing, squamous temporal.
  • Floor: Open to neck.
• Communications & Key Foramina:
  • Foramen Ovale: V3, Acc. meningeal a., Lesser petrosal n., Emissary v. (📌 OVALE)
  • Foramen Spinosum: Middle meningeal a./v., nervus spinosus.
  • Pterygomaxillary Fissure: To pterygopalatine fossa.
• Contents Overview:
  • Muscles: Medial/Lateral pterygoids, temporalis (inf. part).
  • Nerves: V3 branches, chorda tympani, otic ganglion.
  • Vessels: Maxillary artery (1st/2nd parts), pterygoid venous plexus.

⭐ Foramen Ovale transmits: Mandibular Nerve (V3), Accessory meningeal artery, Lesser petrosal nerve, Emissary vein.

Muscles & Mandibular Nerve - Chew & Feel Central

Muscles of Mastication: All innervated by Mandibular Nerve (CN V3).

Mandibular Nerve (CN V3): Mixed; exits Foramen Ovale.

• 📌 Mnemonic (Branches): "Bad Apples Look Incredibly Mouthwatering" (Buccal, Auriculotemporal, Lingual, Inferior Alveolar, Motor branches).
• From Trunk: N. to medial pterygoid, Meningeal br.
• Anterior Div (motor focus): Nerves to masseter, temporalis, lat. pterygoid; Buccal n. (sensory).
• **Posterior Div (sensory focus):
  • Auriculotemporal n. (sensory; parotid secretomotor via otic ganglion).
  • Lingual n. (sensory ant. 2/3 tongue; +chorda tympani CN VII).
  • Inferior alveolar n. (sensory lower teeth; N. to mylohyoid motor; Mental n. terminal).

Otic Ganglion:

• Location: Infratemporal fossa, medial to V3, inferior to foramen ovale.
• Function: Parasympathetic; relays lesser petrosal n. (CN IX) fibers to parotid gland via auriculotemporal n. (secretomotor).

⭐ Lateral pterygoid is the only muscle of mastication that primarily opens (depresses) the jaw.

Maxillary Artery & TMJ - Blood, Bites, Breaks

• Maxillary Artery: From ECA.
  • 1st (Mandibular): Middle Meningeal A. (→ foramen spinosum), Inferior Alveolar A.
  • 2nd (Pterygoid): Muscular branches (to masticatory muscles).
  • 3rd (Pterygopalatine): Sphenopalatine A. (terminal), Infraorbital A., Post. Sup. Alveolar A.

![Maxillary artery branches in temporal/infratemporal regions](https://ylbwdadhbcjolwylidja.supabase.co/storage/v1/object/public/notes/L1/Anatomy_Head_Temporal_and_Infratemporal_Regions/d6c076ad-212a-4e69-9235-fdf9303ad698.jpg)
> ⭐ The Middle Meningeal Artery, branch of 1st part maxillary artery, enters via foramen spinosum. Rupture (e.g. pterion fracture) causes extradural hematoma.

• Pterygoid Venous Plexus:

  • Location: Around lateral pterygoid muscle.
  • Drains: To maxillary vein.
  • Connects: Cavernous sinus, facial vein.
  • Clinical: Infection spread to cavernous sinus.

• Temporomandibular Joint (TMJ):

  • Type: Synovial (condylar & hinge).
  • Articular Surfaces: Mandibular condyle, temporal bone's articular fossa & tubercle.
  • Articular Disc: Divides joint; upper (gliding), lower (hinge).
  • Ligaments: Lateral, Sphenomandibular, Stylomandibular.
  • Movements & Muscles:

    Movement	Primary Muscles
    Elevation	Masseter, Temporalis, Medial pterygoid
    Depression	Lateral pterygoid, Suprahyoids
    Protrusion	Lateral pterygoid, Medial pterygoid
    Retrusion	Temporalis (post.), Masseter (deep)
    Lateral	Contra Pterygoids, Ipsi Temporalis

• Key Clinicals:

  • TMJ Dislocation: Anteriorly; mandible open.
  • Frey's Syndrome: Gustatory sweating (auriculotemporal n. injury).
  • Trismus: Limited mouth opening (pterygoid spasm).

High‑Yield Points - ⚡ Biggest Takeaways

• Muscles of mastication: Innervated by Mandibular N. (V3). Lateral pterygoid opens jaw.
• Mandibular N. (V3): Exits foramen ovale. Middle Meningeal A. (maxillary branch) through foramen spinosum.
• Otic Ganglion: Medial to V3; relays CN IX parasympathetics to parotid via auriculotemporal N.
• Chorda Tympani (CN VII): Joins Lingual N. (V3); taste (ant. 2/3 tongue) & secretomotor.
• Inferior Alveolar N.: V3 branch, supplies lower teeth, enters mandibular foramen.
• Pterygoid Venous Plexus: Risk for infection spread to cavernous sinus_