Pterygopalatine fossa

Why this matters

Almost everything that makes the upper jaw work passes through one fat-filled space of well under a millilitre, about half a dental cartridge, behind the maxilla. The maxillary nerve crosses it and hands off the branch that supplies the upper molars; the third part of the maxillary artery loops through it and sends one terminal branch out through six of its seven doors - every one except the foramen rotundum, which carries V2 in and returns only small emissary veins; and the pterygopalatine ganglion hangs in it, relaying the fibres that make the lacrimal, nasal and palatal glands secrete.

The big picture

The pterygopalatine fossa is the junction box of the midface. Sensory traffic arrives from the middle cranial fossa through the foramen rotundum as the maxillary nerve, is redistributed to the upper teeth, palate, nose and midface skin, and leaves forwards through the inferior orbital fissure as the infraorbital nerve.

The 15 cards in this lesson

1. 01A room of about 0.87 cm3, with three tenants
2. 02Four walls, one open side, one apex
3. 03Seven doors, and the ones books miscount
4. 04Door by door: destination and traffic
5. 05V2 crosses the fossa and changes its name
6. 06The superior dental plexus is a plexus, not three territories
7. 07Behind the tuberosity: the anatomy of the posterior superior alveolar block
8. 08The ganglion and its three roots
9. 09Four branch groups out of one ganglion
10. 10The lacrimal relay your textbook draws is one route of two, and rarely the only one
11. 11The third part of the maxillary artery is a coil, and the veins are the first thing you meet
12. 12One branch per door: the memory hook
13. 13The greater palatine canal: the one door a dentist can see
14. 14Clinical alert — in the lesson
15. 15Where the evidence about this fossa stops

You have got it when

You can describe the fossa as four bony walls, one open lateral side and one inferior apex, and say what forms each; name every communication and where it goes, and say why published lists disagree on the total; sort V2's branches by segment so that only the posterior superior alveolar nerve appears as a fossa branch; state the three roots of the pterygopalatine ganglion and which one synapses; map each terminal…