[Bone distraction using an external fixator: a new mandibular lengthening technic. A preliminary study apropos of 2 cases of children with mandibular hypoplasia].

The authors expose a technical innovation concerning mandibular lengthening without any bone graft, by applying to the mandibular Ilizarov's principles about limb lengthening by osseous distraction. This surgical technique concerns children with mandibular hypoplasia, like the Hanhart's syndrome (aglossia-adactylia, first observation), or Hemifacial Microsomia (second observation). The purpose of this new technique is mandibular lengthening with functional and aesthetic correction of the mandibular growth deficiency, and minimal morbidity. A specialist staff is essential to realize a distraction device with his minimal and appropriate shape for children, as well as a protection device conception. This external distraction device is placed with transmandibular pins. After mandibular corticotomy by endobuccal incision, the distraction is accomplished, at home by the parents, at the rythm of 1 mm p. two days. The distraction goes on about 2 months, depending on the lack of mandibular growth, and a retention device, much more light, is necessary during 8 weeks more to stabilize the osteogenesis. At the term of an eight weeks gradual distraction, the mandibular lengthening is 17.5 mm for the horizontal ramus (first observation), and 13 mm for the vertical ramus (second observation). The functional and aesthetic results, the swift and secure surgical procedure, lead to put forward this mandibular distraction technique in any mandibular or facial defects.