[Three-dimensional modeling of mandibular distraction]

Facial hemi-atrophy affects 1 in 4000 or 5000 children. We propose treating this deformation of the 1st branchial arch with the "bone distraction" lengthening technique first described by Ilizarov in the 1950s, which has already been employed with the mandible. We have modelled mandibular distraction in facial hemi-atrophy patients and discuss the benefits of such pre-surgical planning encompassing the assistance of pre- and post-operative as well as surgically coordinated orthodontic therapy. Using X scanner views of a 5 year-old girl patient, we have developed a distraction-simulation software, which makes the pathological side harmonious with the healthy side along the medial sagittal plane. In order to obtain facial symmetry, put bones in balance, and orient the occlusal plane horizontally, essential requisites of occlusal stability, it is necessary: to employ a 2 or 3-dimensional distractor, to pre-plan the distraction and screw positioning, to set up a fixed orthodontic treatment plan prior to beginning distraction therapy.