Pediatric Anatomy of the Anterior Clinoid Process on Computed Tomography Images

<b>Objective</b> To show the change in the anterior clinoid process (ACP) morphology in children with advancing age. <b>Methods</b> Radiologic images of 180 subjects aged 1 to 18 years were included in the work. The length (ACPL), width (ACPW), and angle (ACPA) of ACP, and the distance (DisACPOS) of ACP to the optic strut (OS) were measured. ACP pneumatization and OS location types were noted. <b>Results</b> ACPL, ACPW, and ACPA, and DisACPOS were measured as 12.34 ± 2.29 mm, 4.52 ± 1.03 mm, 26.26 ± 4.30°, and 5.10 ± 1.12 mm, respectively. ACP pneumatization was identified in 30 (8.3%) sides. Four types regarding its pneumatization were observed: Type 0 in 91.7% out of 360 sides, Type 1 in 2.5%, Type 2 in 3.6%, and Type 3 in 2.2%. Three configurations regarding OS location types were observed as follows: Type C in 3.6% out of 360 sides, Type D in 51.7%, and Type E in 44.7%. Linear function was calculated as <i>y</i> = 9.377 + 0.312 × age for ACPL, <i>y</i> = 3.716 + 0.084 × age for ACPW, and <i>y</i> = 3.808 + 0.136 × age for DisACPOS. <b>Conclusion</b> ACPL, ACPW, and DisACPOS increased, but ACPA did not vary with advancing ages in children. OS was located more posteriorly in children compared with adults. Most of ACP pneumatization was seen after prepubescent period.