Dual midfacial distraction osteogenesis: Le Fort III minus I and Le Fort I for syndromic craniosynostosis.

Abstract

Midfacial hypoplasia has been corrected by Le Fort III or monobloc forward advancement in one stage in syndromic craniosynostosis, but recently developed distraction osteogenesis has been in use. Whereas the amount of forward mobilization in Le Fort III conventional osteotomy is determined by the preplanned fabricated interdental splint, that in Le Fort III distraction is determined by the positions of the inferior orbital rim, malar complex, and nose. Therefore, the forward mobilization of the upper part of the midface may sometimes be insufficient when one focuses on the final occlusion, and the occlusion might not be satisfied when the forward mobilization is sufficient. Correction of the midfacial hypoplasia should be considered differently in the upper and lower portions of the midface. The upper portion contains the inferior orbit and nose, and the lower portion contains the occlusal structure of the maxillary dentoalveolar portion with the mandible. Separating the midface into two portions and conducting the distraction osteogenesis in both portions separately in different amounts and vectors of distraction is described in this article. Although distraction of the upper portion of the midface can be conducted in one direction with an internal device, distraction of the lower portion of the midface is preferred for conduction by a controllable device because of the need to obtain the preferred occlusion. To obtain better functional and aesthetic results in midfacial distraction in adults and adolescents with syndromic craniosynostosis, dual Le Fort III minus I and Le Fort I midfacial distraction osteogenesis was performed in four cases (in two patients with Crouzon syndrome and in two patients with Apert syndrome). Two females and two males are described (age range, 13 to 26 years). An internal device was used for the upper portion of the midface and an external device was used for the lower portion. The amount of distraction ranged from 14 to 21 mm in the upper portion of the midface and from 11 to 18 mm in the lower portion. No particular complications were noticed over a follow-up period of 10 to 38 months (average follow-up, 19.8 months).