Numerical variations and localization of foramen spinosum in 3D-CT images

Objectives: The structures passing through the foramen spinosum and its neurovascular relationships are of great importance for surgical approches directed to middle cranial fossa. The aim of the present study was to examine the number and location of the foramen spinosum (FS) in 3D-CT images. Methods: The study was retrospectively conducted on 3D-CT images of 177 adults. Firstly, the transverse section passing through the upper edge of the orbit, extending parallel to the Frankfurt plane was chosen. Then, the x and y-axes were determined on that transverse section. The coordinates, number, and location of the FS with respect to the foramen ovale (FO) were identified accordingly on x and y-axes. Results: While 1 FS was present in 90.96% of a total of 354 sides of 177 heads, there were 2 FS and 3 FS in 8.76% and 0.28% of the sides, respectively. The FS was located posterolaterally in 97.68%, posteriorly in 2.06%, and laterally in 0.26% with respect to the FO. In terms of FS coordinates, there was no statistically significant difference between gender and sides in the distance of the FS to the x-axis, but there was a statistically significant difference between gender and sides in the distance of the FS to the y-axis. Conclusion: Evaluation of the number of the FS and its location would help identifying and preserving neighbouring neurovascular structures during surgical interventions directed to the middle cranial fossa.