Measurements of orbital volume using cone-beam computed tomography in eye movement abnormalities

Purpose: To measure the orbital volume in adult patients with unilateral eye movement abnormalities originating in childhood.Methods: Cone-beam computed tomography was performed in 2 patients with eye movement abnormalities. A 28-year-old woman was treated because of right divergent squint originating at 8 years of age after penetrating corneal trauma. A 38-year-old man was examined because of abnormal head posture caused by left superior oblique underaction originating at 6 years of age. Orbital scans were analyzed with Cranioviewer 3D craniofacial cephalometric program. We measured bony orbital area in 6 slices (in ventro-dorsal direction per 4.8 mm) in every orbit on coronal scans.Results: The volume was more in the orbit with unilateral divergent squint and less in the orbit with unilateral superior oblique underaction compared to the contralateral orbital volume measurements. Conclusion: Cranioviewer 3D craniofacial cephalometric program is suitable for volumetric analysis of the bony orbit on cone-beam computed tomography files. The development of the orbit can be influenced by extraocular muscle movements