[Hemifacial microsomia treated with mandibular lengthening using intraoral distractors. On precise indications].

Mandibular hypoplasia in the hemifacial microsomia have largely benefited from distraction techniques especially intraoral. In fact, these techniques are possible in the child, replacing him in a better morphological, psychological and functional configuration. They can redynamise growth and, in any case, diminish secondary distant effects. The authors, from precise criteria, propose a surgical classification to facilitate the therapeutic decision. Intraoral and sometimes bidirectional distraction, whose results are equivalent to external distraction, present numerous advantages that, in the majority of cases, make it preferred now to external distraction. Its three-dimensional (3D) effect on bone and soft tissues and the long term follow-up must be evaluated more objectively, as pre and post-distraction stereolithographic or 3D photogrammetric may get. It must be considered in the child as the first step of skeletic surgery preparing to a facilitated second step orthopedic, orthodontic or orthognathic after puberty. In the young adult, it is in competition with conventional surgery but the slow progressive process, kind with the temporo-mandibular joints, allows in mandibular asymmetries an adaptation having avoided the need for controlateral osteotomy or a bone graft.