Infratemporal Fossa - LO 2

2. What bony structures & landmarks delineate the temporal fossa and infratemporal fossa?

A lateral view of the temporal region can be divided into 2 main parts: temporal fossa (superior) & infratemporal fossa (inferior). These fossae are demarcated by the zygomatic arch, and are continuous with one another.

Temporal Fossa

Boundaries:

• • Medial: frontal, parietal, temporal, and sphenoid bones

    • Pterion: junction of these 4 bones; middle meningeal a., anterior branch typically lies deep to pterion

  • Lateral: temporal fascia

  • Anterior: posterior surface of frontal process of zygomatic & posterior surface of the zygomatic process of frontal

  • Superior: superior and inferior temporal lines

  • Inferior: zygomatic arch (laterally) & infratemporal crest of greater wing of sphenoid (medially)

Contents:

• • Temporalis m.

  • Deep temporal aa. & nn.

  • Superficial temporal a.

  • Zygomaticotemporal n.

Infratemporal Fossa

The infratemporal fossa can be visualized as having a wedge shape. It is located deep to the masseter muscle and zygomatic arch (to which the masseter attaches).

The infratemporal fossa communicates with:

• • Temporal fossa (superiorly)

  • Pterygopalatine fossa (medially) through the pterygomaxillary fissure

  • Orbit (anteriorly) through inferior orbital fissue

  • Middle cranial fossa through foramen ovale and spinosum

Boundaries:

• • Lateral: Ramus of mandible

  • Medial: Lateral pterygoid plate of sphenoid

  • Anterior: Posterior surface of maxilla

  • Posterior: Mastoid & styloid processes and tympanic plate of temporal bone

  • Inferior: Medial pterygoid m. at attachment site (angle of mandible)

  • Superior (roof): Greater wing of sphenoid

Contents:

• • Muscles:

    • Distal end of temporalis m.

    • Pterygoid mm.

  • Maxillary a.

  • Pterygoid venous plexus

  • Nervous tissue:

    • Otic ganglion

    • Mandibular n. (V3) & branches

    • Chorda tympani