pterygopalatine fossa anatomy : contents and communications
Boundaries of Pterygopalatine Fossa
It is a wedge shaped space deep on the side of the skull. It derives its name from 2 of its boundaries.
- posteriorly : The posterior boundary is the lateral pterygoid plate of the sphenoid.
- medially : The medial boundary is the perpendicular plate of the palatine.
- anteriorly : . The anterior wall is the posterior surface of the maxilla.
- inferiorly: The anterior and posterior wall converges inferiorly so it’s wedge shaped in outline.
Communications of Pterygopalatine Fossa
The pterygomaxillary fissure (fissure means crack) is between the lateral pterygoid plate and posterior surface of the maxilla. This opening allows the pterygopalatine fossa to communicate laterally with the infratemporal fossa. The pterygomaxillary fissure allows the maxillary artery to enter the pterygopalatine fossa (very important).
It communicates with the orbit anteriorly and superiorly through the inferior orbital fissure. It allows nerves and vessels (namely the infraorbital) to enter the orbit from pterygopalatine fossa.
On the medial wall of the fossa is a round foramen called the sphenopalatine foramen. It allows fossa to communicate medially with the nasal cavity. The sphenopalatine artery and several branches of V2 enter the nasal cavity through this foramen.
Posteriorly in the posterior wall there is the palatine canal (greater palatine canal), which lead to the palate. This canal splits further distally into an anterior greater and posterior lesser canal. These canals open up into the palate by foramina and allow communication between the pterygopalatine fossa and palate. There are vessels that supply the palate in the canal.
In the posterior wall we have 3 openings:
1. The foramen rotundum that communicates posteriorly with the middle cranial fossa. V2, the maxillary nerve, runs through this foramen rotundum and immediately enters the pterygopalatine fossa.
2. Below that is the pterygoid canal, which is a bony canal through the sphenoid bone. It also communicates with the middle cranial fossa posteriorly. It enters right on the region of the foramen lacerum of the middle cranial fossa. This is where the pterygoid canal begins. It carries the nerve of the pterygoid canal and that’s how it reaches the pterygopalatine fossa.
3. The last opening is the palatovaginal canal (or pharyngeal canal) that transmits a small branch of V2 into the nasopharynx. This canal opens up in the posterior wall and communicates with the nasopharynx.
Contents of Pterygopalatine Fossa
- Maxillary Nerve V2
- Pterygopalatine ganglion
- Maxillary Artery (3rd part)