Midface correction in patients with Crouzon syndrome is Le Fort III distraction osteogenesis with a rigid external distraction device the gold standard?

Introduction: Le Fort III distraction osteogenesis with a rigid external distraction device is a powerful procedure to correct both exorbitism and impaired airways in faciocraniosynostosis. The aim of this study was to investigate treatment effect, perioperative parameters and volumetric outcomes after Le Fort III distraction osteogenesis in patients with Crouzon syndrome in a retrospective study design and to explore potential strengths and weaknesses of this procedure.

Materials And Methods: From June 2013 to February 2015, a total of nine children with Crouzon syndrome underwent Le Fort III distraction osteogenesis with a rigid external distraction device (RED device, KLS Martin, Tuttlingen, Germany). Along with perioperative parameters, sleep study reports, traditional cephalometric analysis, three-dimensional imaging and photographs were evaluated for severity of disease and therapeutic effect and structural and functional changes of the upper airway preoperatively, after device removal and one year postoperatively.

Results: Surgery for Le Fort III distraction was performed at a median age of 12.5 years (SD 2.5 months) with an average weight of 43.0 kg (SD 12.9 kg). Mean estimated blood loss was 535.7 ml (SD 128.1 ml), not requiring any red blood cell transfusions. Mean duration of surgery was 240 min (SD 30.6min), average hospital stay eight days (SD 0.5 days) with a planned median ICU stay of 1.7 days (SD 0.4 days) for all patients. There were a total of five minor complications. Exorbitism and Angle class III malocclusions were corrected in all patients. No patient showed velopharyngeal problems postoperatively. The average amount of distraction was 18.4 mm (14-26 mm). Average length of the distraction period was 18.3 days (SD 0.4 days), with a total distraction plus consolidation time of three months (SD 0.25 months). In two patients, vector correction was performed during distraction. A counterclockwise movement despite vector correction, clinically resulting in an open bite, was observed in one of these two patients. Eight of the nine patients showed a frontal overbite at the end of the distraction period. Cephalometric analysis revealed a significant increase of Sella-Nasion-Point A angle (SNA) from 76.0° (+/- 2.9; T1) to 86.0° (+/- 3.4; T2) (p = 0.006) and growth-related point A-Nasion-point B angle (ANB) from -4.8° (+/-3.7) to 5.7° (+/-4.8) (p = 0.001) from preoperatively to device removal and stable results one year postoperatively. Upper airway structure and respiratory function were improved clinically after the Le Fort III DO treatment in all cases with an average posterior airway space increase from 3199 mm (+/- 229.6 mm) to 8917,7 ml (+/-415.1 mm) (T1 to T2). Surgical outcome was judged good to excellent both by patients and families and the craniofacial team.

Conclusion: Le Fort III DO with a rigid external distraction device in patients with Crouzon syndrome is a powerful and reliable surgical procedure that reliably produces a more significant change of appearance than most other single procedures routinely performed by craniofacial surgeons. It effectively treated sleep apnea in the affected patients. In our collective, the maxilla remained stable after advancement without any relapse, but there was no subsequent anterior growth on one year follow-up. Careful vector planning was able to avoid frontal open bite in eight patients. Complication rates were acceptably low and patients' functional and esthetic outcome was high.