LeFort III distraction in patients with syndromic craniosynostosis: Is overcorrection beneficial?

Background: Patients with syndromic craniosynostosis often require LeFort III advancement surgery due to significant midface retrusion. As long-term outcome is imperative, this study aimed to investigate the effect of LeFort III and distraction osteogenesis with overcorrection. Methods: Six consecutive patients with syndromic craniosynostosis and significant midface hypoplasia were enrolled. They underwent LeFort III osteotomy with over-distraction at an average age of 10.3 years. Longitudinal lateral cephalograms were collected at three time points of pre-operation (T0), early post-distraction (T1), and skeletal maturity (T2). Changes in cephalometric measurements and dental relationships were assessed between the timings. Results: LeFort III distraction created an anterior advancement of 20.8 mm at the anterior nasal spine (ANS) and 22.7 mm at the A-point immediately after the procedure (T0 to T1), and led to an overcorrected overjet of 9.0 ± 7.5 mm at T1. From T1 to T2, neither surgical relapse or maxillary forward development was observed. However, continuous mandibular development in the anterior and inferior direction resulted in a gradual phenotypic reversion, marked by decreasing ANB angle, Wits relationship, and overjet. At the end point, only one patient necessitated orthognathic surgery in adulthood. Conclusion: LeFort III distraction effectively achieved midface overcorrection and ensured favorable surgical stability. Sufficient overcorrection at the mixed dentition stage is beneficial in preventing long-term midface relapse and reducing the need for further skeletal interventions.