INTRODUCTION OF AN INTRAORAL BONE-LENGTHENING DEVICE

Distraction osteogenesis, initially described in the enchondral bones of the axial skeleton,(1,2,6,8) has has been applied recently to the membranous bone of the craniofacial skeleton. Preliminary studies on the canine mandible(3,4) led to the first clinical trials in 1989 of bone lengthening involving the human mandible.(5) Thus far the technique has been applied unilaterally in the treatment of hemifacial microsomia and bilaterally in patients with Nager syndrome, Treacher Collins syndrome, and developmental micrognathia. The main criticism of the technique has been the residual scars along the cheek. The currently available devices are sufficiently large to require a skin incision along the mandible to permit their application. As with devices used on the long bones of the extremity, this device lies externally, and the half-pins cut through the skin during active expansion. In order to avoid external scars, we have investigated the use of a miniaturized bone lengthener (Howmedica Corp., Rutherford, N.J.) that is suitable for intraoral placement along the buccal surface of the mandible (Fig. 1 and Table I).