Long-term stability of LeFort III distraction osteogenesis with a rigid external distraction device in a patient with Crouzon syndrome.

A 6-year-old boy, diagnosed with Crouzon syndrome, had moderate exorbitism, a concave profile, an anterior crossbite of -4.0 mm, and a skeletal Class III jaw-base relationship caused by midfacial hypoplasia. At age 8 years 9 months, a LeFort III osteotomy was performed, and distraction osteogenesis was immediately started with the rigid external distractor system. The midface was advanced approximately 10.0 mm for 6 days, including overcorrection. After the distraction, a reverse headgear was used for 6 years to prevent relapse and to accelerate expected growth. At age 16 years 5 months, after extraction of the maxillary first premolars and mandibular third molars, 0.022-in preadjusted edgewise brackets were placed to treat the edge-to-edge incisor relationship and minor crowding. After 13 months of treatment, the facial profile was significantly improved, and an acceptable occlusion was achieved. During the 9-year observation period after the distraction, acceptable facial growth occurred, and no relapse of the maxillary advancement was observed. However, syndrome-specific growth and methodologically induced relapse should be considered when planning a LeFort III distraction in children for the treatment of Crouzon syndrome.