Orbital volume changes during growth and development in human children assessed using cone beam computed tomography

OBJECTIVES: To measure growth-related changes in orbital volume from childhood to the late teenage years using cone-beam computed tomography (CBCT) scans. METHODS: This retrospective cohort study involved 65 (24 male, 41 female) healthy Caucasian children (ages 6-18 years) with existing serial craniofacial CBCT scans. CBCT scans were available for 292 orbits. Each orbit was transformed into a closed space with well-defined boundaries, and orbital volume was measured using manual segmentation. A novel statistical analysis was applied to extract the maximum amount of longitudinal information from the data. Intra- and inter-operator correlation coefficients were calculated from replications performed on a random subset of 10% of the sample. RESULTS: Orbital volume increased at a rate of 1-2% annually until the late teenage years. Intra- and inter-operator agreement between repeated measurements were >90%. CONCLUSIONS: Orbital volume increases by 1-2% per year throughout childhood continuing until the late teenage years. This annual increase is large enough to be clinically relevant as it may lead to less-than-optimal long term surgical outcomes when reconstructive surgery for the pediatric anophthalmic socket is required.