Evolution of Bandeau Shape, Orbital Morphology, and Craniofacial Twist after Fronto-Orbital Advancement for Isolated Unilateral Coronal Synostosis: A Case-Control Study of 2-Year Outcomes

Background: The authors' purpose was to quantify the change in unicoronal synostosis symmetry between presentation (time 0), after fronto-orbital advancement (time 1), and 2 years later (time 2). Methods: Bandeau/orbital symmetry ratios and skull base/midface twists were measured on computed tomographic scans of consecutive isolated unicoronal synostosis patients. Comparisons were made across three time points and against normal controls. Results: Forty-three unicoronal synostosis patients and 36 controls were included. The mean bandeau ratio (symmetry = 1) changed from 0.76 (time 0), to 1.13 (time 1), and then to 1.01 (time 2). The median bandeau ratio change from time 1 to time 2 was -9.1 percent and was impacted by the degree of time 1 asymmetry. The odds of a desired symmetric or overcorrected result (bandeau ratio > 1.0) at time 2 were increased in patients with less severe preoperative asymmetry (OR, 4.2; p = 0.04) and in those who obtained symmetry or overcorrection at surgery (OR, 4.9; p = 0.02). Craniofacial twist did not significantly change after surgery but decreased at time 2. Orbital height ratios were 1.08, 1.00, and then 1.02 at time 2, respectively. The orbital width ratio was not significantly impacted by surgery, remaining at 0.89 at time 2. Conclusions: Overcorrection of the unicoronal synostosis bandeau resulted in these patients being five times more likely to have a desired result at time 2. Patients with a more severe brow presentation were four times more likely to be asymmetric at time 2. Orbital height was improved, but attention should be directed at addressing orbital width.