PMC

The different pathways identified in the coronal plane: (a) The greater palatine canal travels in an inferior-lateral direction from the PPF and then in a directly inferior direction; (b) the greater palatine canal travels in an inferior-lateral direction for a certain distance and then changes to an inferior-medial direction through the remainder of the canal; (c) the greater palatine canal first travels in an inferior-lateral direction, then in a directly inferior direction, and finally in an inferior-medial direction; (d) the greater palatine canal travels in a directly inferior direction from the pterygopalatine fossa

The different pathways identified in the sagittal plane: (a) The greater palatine canal travels in an anterior-inferior direction from the pterygopalatine fossa; (b) the greater palatine canal travels in an inferior direction and then in an anterior-inferior direction through the remainder of the canal; (c) the greater palatine canal first travels in an inferior direction, then changes to an anterior-inferior direction, and subsequently travels in an inferior direction through the remainder of the canal

A CBCT sagittal cut at the level of the pterygopalatine fossa illustrating the method of determining the length of the greater palatine canal as considered by our study (at the level of the vidian canal); (a) the vidian canal and (b) the lower opening of the greater palatine canal corresponding to the greater palatine foramen.

The images above demonstrate the appearance of anatomical structures on CBCT images described above; coronal view (a) and sagittal view (b). From the coronal view, the pterygopalatine fossa and greater palatine canal can be seen lateral to the nasal cavity. The pterygopalatine fossa begins below the middle cranial fossa and meets the greater palatine canal below which extends to enter the hard palate at the greater palatine foramen. In the sagittal view, the pterygopalatine fossa and greater palatine canal can be seen again, posterior to the maxillary sinus. The pterygoid canal is visible here, entering the pterygopalatine fossa from the posterior. The midpoint of the pterygoid canal was determined in this plane for each canal and used as the superior point of measurement.