Relapse following frontofacial advancement using the rigid external distractor.

Multisutural synostosis may result in frontofacial hypoplasia. The aesthetic and function problems arising from this can be corrected by frontofacial advancement, either by monobloc or bipartition osteotomy. Significantly larger, safer advancements can be achieved using distraction osteogenesis when compared to conventional osteotomy. However, the stability of this technique has been questioned. A retrospective study of 21 patients with craniofacial dysostosis who underwent frontofacial advancement osteotomies using the rigid external distractor system was undertaken. Twelve were distracted on protocol 1 (24 hours after surgery at 1.5 mm/d). Nine were distracted on protocol 2 (7 days after surgery at 1 mm/d). A 6-week consolidation period was used. Changes in frontofacial advancement in the sagittal plane were measured preoperatively, immediately, at 6 months, and where possible thereafter annually using lateral cephalograms and three-dimensional computed tomography scans. The midface was distracted an average of 16.4 mm with a range of 12 to 22 mm as measured in the sagittal plain. Relapse was seen only in 3 of 21 patients, and all of these patients were distracted using protocol 1. Distraction osteogenesis of the frontofacial skeleton using the rigid external distractor frame is generally stable. In this series, a longer latency period and reduced distraction rate resulted in greater stability. Overdistraction in the growing infant is recommended to allow for completion of growth. Overdistraction is not needed to compensate for potential relapse.