Morphometric analysis of vidian canal and its relations with surrounding anatomic structures by using cone-beam computed tomography

Background: We identified the vidian canal (VC) in a Turkish subpopulation on cone-beam computed tomography (CBCT) images and explored its anatomic relationships; the canal serves as an anatomic pathway during endonasal surgical approaches. Materials and methods: Coronal and axial CBCT images of 100 patients (50 males and 50 females) were evaluated (slice thickness and interval, 0.5 mm). We measured the length of the VC length, extent of VC pneumatisation into the sphenoid sinus, position of the VC relative to the medial pterygopalatine plate (MPP), pterygopalatine fossa (PPF) depth, and VC-VC, VC-MPP, and VC-foramen rotundum (FR) distances, the angle between the posterior end of the middle turbinate and the lateral part of the VC anterior opening, and the angle between the VC and the palatovaginal canal. Results: The mean VC length was 13.09 +/- 2.07 and 13.01 +/- 2.12 mm on the right and left sides, respectively. Relative to the MPP, the VC was located medially in 54.5% of patients, on the same level in 36%, and laterally in 9.5%. Pneumatisation was of grade I in 24% of patients, grade II in 33%, grade III in 23.5%, and grade IV in 19.5%. The VC-FR and VC-MPP distances were significantly greater on the left side. The angle between the posterior end of the middle turbinate and the lateral part of the anterior VC opening was significantly greater on the right side. The VC-VC distance was significantly greater when the VC lay lateral to the MPP. Conclusions: Anatomic characteristics of the VC on CBCT images unique to Turkish populations should be kept in mind during surgery.