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

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.

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.

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.

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.