Assessment of Soft Tissue Changes Relative to Bone Following Box Osteotomy and Facial Bipartition for Correction of Hypertelorism

Box osteotomy (BO) or facial bipartition (FB) are used for the surgical correction of hypertelorism. There is a paucity in the literature assessing the degree to which bony resection translates into soft tissue movement. This study analyzes the bony and soft tissue changes achieved with BO and FB.1,2 A retrospective review was conducted evaluating patients who underwent BO or FB at our institution from 2005 to 2022. Demographics, medical history, and perioperative data were recorded. Correction of the interdacryon distance and intercanthal distance were measured on pre- and postoperative computed tomography scans. Data normality was determined, and independent t-test (parametric) and Wilcoxon rank-sum test (non-parametric) were utilized. The ratio of bone-to-soft tissue change was computed by calculating the change in the intercanthal distance for every 1-millimeter change in the interdacryon distance. Twenty-seven patients were included, of which 20 underwent FB and 7 BO. There was a significant improvement in the interdacryon distance (27.9 mm to 21.6 mm; P < .001) and intercanthal distance (43.4 mm to 28.4 mm; P = .003) for FB patients. Similarly, there was a significant improvement in the interdacryon distance (34.8 mm to 25.6 mm; P= .018) and intercanthal distance (48.9 mm to 41.0 mm; P = .036) for BO patients. The percent change in the interdacryon distance was 23.1% (FB) and 28.3% (BO; P = .216), whereas the percent change in the intercanthal distance was 11.2% (FB) and 16.4% (BO, P = .041). The ratio of bone-to-soft tissue change was 1-to-0.8 across both cohorts (BO: 1-to-0.9, FB: 1-to-0.7; P = .224). Box osteotomy and facial bipartition effectively correct hypertelorism, demonstrating significant bone and soft tissue changes. Our findings revealed that 1 mm of interorbital bone resection correlated with 0.8 mm change in the overlying soft tissue for both hypertelorism-correcting procedures.