Temporal & Infratemporal Fossae

Temporal & Infratemporal fossae

Temporal fossa: boundaries

  • Anterior: Frontal process of Zygomatic bone & Zygomatic process of frontal bone
  • Posterior & Superior: Temporal lines
  • Lateral: Temporal fascia- from Temoral lines to Zygomatic arch
  • Inferior: Zygomatic arch & Infratemporal crest of greater wing of sphenoid
  • Floor: Pterion
  • Pterion is the point where the four bones- Frontal, Parietal, Temporal & Sphenoid meet.
“Temporal

Contents of Temporal fossa

-the major str is Temporalis muscle, also the Zygomaticotemporal br of the Maxillary nerve[V2] passes through the fossa.

Infratemporal fossa: boundaries

  • Medial: Lateral pterygoid plate
  • Lateral: Mandible ramus & coronoid process
  • Anterior: Maxilla
  • Posterior: Tympanic plate, mastoid & styloid processes of temporal bone

Contents of Infratemporal fossa

  1. Muscles:
    • Medial pterygoid
    • Lateral pterygoid
    • Temporalis
  2. Vessels:
    • Maxillary artery
    • Pterygoid venous plexus
  3. Nerves: these nerves pass through infratemporal fossa-
    • Mandibular nerve
    • Chorda tympani
    • Otic ganglion
    • Auriculotemporal nerve
    • Inferior alveolar nerve
    • Lingual nerve

Muscles of Mastication

The following are muscles of mastication & are supplied by the Mandibular division of Trigeminal Nerve, V3.
Of the four muscles of mastication, Temporalis fills the temporal fossa, Medial & Lateral pterygoids are in the Infratemporal fossa & Masseter is lateral to Infratemporal fossa.

Muscles of mastication

Muscles Origin Insertion Nerve suppply Function
Temporalis Temporal fossa Coronoid process of mandible Elevation & retraction of mandible
Masseter Zygomatic arch Ramus of mandible Elevation of mandible
Medial pterygoid Tuberosity of maxilla, Palatine process
& medial surface of lateral pterygoid plate		 Angle of mandible Elevation & side to side movements of mandible
Lateral pterygoid Skull & lateral surface of lateral pterygoid plate T-M joint Protrusion & side to side movements of mandible

<<< Facial artery- course & branches >>>

Course: The Facial artery branches from anterior surface of the External carotid artery(Other branches of External Carotid artery:SALFOPMS -Superior Thyroid, Ascending Pharyngeal, Lingual, Facial, Occipital, Posterior Auricular, Superficial Temporal & Maxillary arteries) in the Carotid triangle, passes obliquely beneath the digastric & stylohyoid muscles, appears at lower border of mandible after passing posterior to submandibular gland. It curves upwards over the body of mandible anterior to Masseter(where its pulse can be felt) & enters the face. From here it runs upwards & medially to reach the angle of mouth, passes along the side of nose & terminates as angular artery at the medial corner of eye.

Branches:
  • In the Neck–
    1. Ascending palatine artery
    2. Tonsillar artery
    3. Submental artery
    4. Br to submandibular gland
  • Facial branches–
    1. Superior labial artery
    2. Inferior labial artery
    3. Lateral nasal artery
    4. Angular artery

    • <<< Retromandibular vein >>>

    The superficial temporal vein & maxillary vein join to form Retromandibular vein which runs downwards within the parotid gland deeper to facial nerve & then divides into anterior & posterior branches. The Anterior br joins to the facial vein to form common facial vein which drains into Internal Jugular vein. The posterior br joins with posterior auricular vein to form External Jugular vein which drains into subclavian vein.