Infratemporal and Pterygopalatine Fossa (Skull Part 5)

Infratemporal Fossa

• The infratemporal fossa is an irregularly shaped cavity, situated below and medial to the zygomatic arch.
• Superior border: greater wing of the sphenoid bone
• Inferior border: medial Pterygoid muscle
• Anterior border: maxilla
• Posterior border: styloid and condylar processes
• Medial border: sphenoid and palatine bones
• Lateral border: ramus and coronoid process of the mandible
• Functions of the Infratemporal Fossa: contains the muscles of mastication.
• The lateral pterygoid muscle & the medial pterygoid muscle are located within the fossa.
• The masseter & temporalis muscles originate and insert at the borders of the fossa
• It serves as a passageway for many neurovascular structures.
• Structures that pass through the infratemporal fossa:
  • Maxillary artery/vein
  • Middle meningeal vein
  • Posterior division of the mandibular nerve
  • Inferior alveolar nerves
  • Sensory branches of the trigeminal nerve

Pterygopalatine Fossa

• The pterygopalatine fossa is located between the infratemporal fossa and the nasopharynx.
• Structure: inverted pyramidal shape
• Walls: maxilla, palatine, and sphenoid bones
• Anterior border: Posterior wall of the maxillary sinus
• Posterior border: Pterygoid process of the sphenoid bone
• Inferior border: Palatine bone and palatine canals
• Superior border: Inferior orbital fissure of the eye
• Medial border: Perpendicular plate of the palatine bone
• Lateral border: Pterygomaxillary fissure
• The pterygopalatine fossa contains important neurovascular structures and their branches.
  • Maxillary nerve
  • Pterygopalatine ganglion
  • Maxillary artery
• Seven foramina connect the pterygopalatine fossa to the orbit, nasal cavity, oral cavity, middle cranial fossa, and infratemporal fossa.