Evaluation of the Cranial Aperture of the Optic Canal on Cone-Beam Computed Tomography Images and its Clinical Implications for the Transcranial Approaches

Objective: This study aimed to investigate morphometric properties of the cranial aperture (CA) of the optic canal. Methods: Cone-beam computed tomography images of 400 individuals (200 males and 200 females) aged 37.32 +/- 15.87 years were retrospectively examined to assess the morphometry and morphology of the CA. Results: The height and width of CA were found as 4.22 +/- 0.74 mm and 7.27 +/- 1.15 mm, respectively. The distances between the CA and the midsagittal line, the anterior and lateral boundaries of the anterior skull base were measured as 5.77 +/- 1.32 mm, 64.97 +/- 6.36 mm, and 41.00 +/- 4.05, respectively. The angle of the optic canal in the sagittal plane was measured as 7.57 degrees +/- 3.95 degrees, whereas in the horizontal plane as 38.96 degrees +/- 4.36 degrees. The aperture shape was defined as the tear-drop (413 foramina, 51.62%), triangular (180 foramina, 22.50%), oval (158 foramina, 19.75%), round (30 foramina, 3.75%), and polygonal (19 foramina, 2.38%). Conclusions: The authors observed that the diameters, and angulations of the CA may change relative to gender and the shape. The anatomic features of CA are important for the positioning of the patient's head, the choice of the appropriate surgical approach or equipment, and the detection of anatomical landmarks during interventions. In this context, our dataset may be beneficial for surgeons helpful as a reference for radiological evaluations.