The Evolution of Unicoronal Synostosis Correction: Long-Term Aesthetic Outcomes of Fronto-Orbital Distraction Versus Traditional Advancement.

Introduction: This study compares the long-term aesthetic outcomes of patients with unicoronal synostosis (UCS) who underwent fronto-orbital distraction osteogenesis (FODO) versus traditional fronto-orbital advancement and remodeling (FOAR).

Methods: Patients treated for nonsyndromic UCS from 2009 to 2023 were retrospectively reviewed. Perioperative and complication characteristics were compared between all patients who underwent FOAR, open FODO, and endoscopic-assisted FODO ("endo-FODO"). Aesthetic outcomes at greater than five years postoperatively were compared between patients who underwent FODO and a contemporaneous cohort of age-matched controls who underwent FOAR. Differences between pre- and postoperative periorbital symmetry ratios, canthal tilt symmetry, orbital dystopia angle (ODA), and frontal bossing angle were calculated, with positive differences representing postoperative improvement.

Results: Forty-one patients were treated at a median age of 9.7, 5.4, and 5.4 months in the FOAR, open FODO, and endo-FODO groups, respectively. Among 28 patients photographed at a median of 6.3 years postoperatively, the FODO cohort demonstrated greater margin-to-reflex distance 1 symmetry (6.5 [-9.3, 0.0] vs. -13.9 [-22.9, -11.5], p=0.010) and canthal tilt symmetry (0.9° [0.2°, 2.9°] vs. 3.3° [2.3°, 5.3°], p=0.004) postoperatively as well as ODA correction (5.4° [4.0°, 7.5°] vs. 3.0° [2.5°, 4.4°], p=0.027) compared to the FOAR cohort. Fewer patients in the FODO cohort exhibited temporal hollowing postoperatively compared to the FOAR cohort (14% vs. 71%, p=0.002).

Conclusions: Compared to FOAR, FODO was associated with greater periorbital symmetry, greater orbital dystopia correction, and reduced temporal hollowing in the long-term. Follow-up to cranial maturity is needed to adequately compare the two techniques.