Cone-beam computed tomography of the orbit and optic canal volumes

PURPOSE: The aim of this study was to measure orbital and optic canal volumes by means of cone-beam computed tomography (CBCT) of human skulls as a prerequisite for estimating alterations of this bony region by this method.

MATERIALS AND METHODS: A total of 200 orbits of 100 adult individuals were investigated. These patients had no history of orbital trauma, dysplasia, or other diseases with a putative effect on orbital growth (female/male = 50/50; age: 20-70 years). Each 10 individuals with a male-to-female ratio of 1:1 constituted a 10-year age group. Area measurements and calculations of volumes were performed with OsiriX software.

RESULTS: Orbital mean volume values did not differ significantly with respect to site. However, orbital volume slightly increased with age, whereas the optic canal volume declined over time. Mean orbital and optic canal volumes were larger in males than in females. Volumetric measurements of the orbit are in line with published data derived from computed tomograms and magnetic resonance images.

CONCLUSION: Orbital and optical canal volumes in adults show sexual dimorphism and alter depending on age. CBCT is suitable for determining orbital volumes and the provided data can be useful, for example, for defining orbital pathologies, to calculate orbital reconstructions, or for use in anthropological studies.