Learning Objective: To describe the location, borders, communications, contents, and clinical importance of the pterygopalatine fossa, with emphasis on the maxillary nerve, pterygopalatine ganglion, and maxillary artery.
The pterygopalatine fossa (PPF) is a bilateral, cone-shaped space located deep in the face. It lies posterior to the maxilla, inferior to the apex of the orbit, and medial to the infratemporal fossa. Despite its small size, it serves as a major neurovascular crossroads, connecting the orbit, nasal cavity, oral cavity, nasopharynx, and middle cranial fossa.
Borders of the Pterygopalatine Fossa
| Boundary | Formed by |
|---|---|
| Anterior | Posterior wall of the maxillary sinus |
| Posterior | Pterygoid process of the sphenoid bone |
| Medial | Perpendicular plate of the palatine bone |
| Lateral | Pterygomaxillary fissure (opens to the infratemporal fossa) |
| Superior | Inferior orbital fissure |
| Inferior | Palatine bone and palatine canals |
Contents
Maxillary Nerve (CN V₂)
- Enters via the foramen rotundum from the middle cranial fossa.
- Gives rise to:
- Infraorbital nerve
- Zygomatic nerve
- Nasopalatine nerve
- Greater and lesser palatine nerves
- Pharyngeal nerve
- Posterior superior alveolar nerve
- Communicates with the pterygopalatine ganglion via two small trunks (pterygopalatine nerves).
Pterygopalatine Ganglion
- The largest parasympathetic ganglion of the head.
- Receives preganglionic fibers from the greater petrosal nerve (CN VII).
- Sends postganglionic secretomotor fibers to:
- Lacrimal gland
- Nasal mucosa
- Palatal and pharyngeal glands
Maxillary Artery (Terminal Branch of ECA)
- Enters via the pterygomaxillary fissure.
- Branches include:
- Sphenopalatine artery → nasal cavity
- Descending palatine artery → hard & soft palate
- Infraorbital artery → face, inferior orbit
- Posterior superior alveolar artery → upper teeth
Communications and Foramina
| Opening | Connects To | Transmitted Structures |
|---|---|---|
| Pterygomaxillary fissure | Infratemporal fossa | Maxillary artery (terminal part), posterior superior alveolar nerve |
| Foramen rotundum | Middle cranial fossa | Maxillary nerve (CN V₂) |
| Pterygoid canal | Middle cranial fossa | Nerve, artery, and vein of the pterygoid canal |
| Pharyngeal canal | Nasopharynx | Pharyngeal branch of CN V₂ and artery |
| Inferior orbital fissure | Orbit | Infraorbital artery/vein, zygomatic nerve |
| Greater palatine canal | Oral cavity | Descending palatine vessels, greater & lesser palatine nerves |
| Sphenopalatine foramen | Nasal cavity | Sphenopalatine vessels, nasopalatine nerve |
Clinical Relevance
Maxillary Nerve Block
- Used in major dental procedures or facial pain management.
- The needle is introduced via the greater palatine canal into the PPF to anesthetize CN V₂.
Chronic Epistaxis
- The sphenopalatine artery (artery of epistaxis) often causes posterior nosebleeds.
- It can be surgically ligated via a transantral approach through the maxillary sinus.
