Midface Osteodistraction: Experimental Studies
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Adi Rachmiel, DMD, Iaron Rabinovich, DMD, Dov Laufer, DMD

Introduction

Currently, surgical treatment for severe midface and orbital deformities includes multiple osteotomies followed by acute defect correction, bone grafting, and fixation with plates and screws. These methods, however, are associated with significant donor site morbidity due to bone graft infection or resorption, leading to relapse (Araujo et al., 1978; Bell & Scheideman, 1981; Laurie et al., 1984; Jackson, 1989). Persson and colleagues demonstrated that relapse following inferior repositioning of the maxilla ranges from 0% to 100% (Persson et al., 1986). Baker and associates also noted a relapse in 30% to 50% of cases when repositioning the maxilla more than 5 mm followed by bone grafting and mini plate fixation (Baker et al., 1992).

Recently, distraction osteogenesis has been proposed as an alternative method of skeletal reconstruction. In the 1950s, Ilizarov developed and popularized this technique for long bones (Ilizarov, 1988; Ilizarov, 1989a, 1989b). He demonstrated that osseous regeneration, if medullary blood supply was preserved, could be enhanced and controlled through the application of tensile forces with external fixation device. Later, Kojimoto and colleagues demonstrated that preservation of medullary blood supply was not essential for successful distraction osteogenesis (Kojimoto et al., 1988). In the past fifty years, this technique has been successfully applied for limb lengthening, deformity correction, and treatment of traumatic bone defects.

Several animal studies on the mandible (Snyder et al., 1973; Michieli & Miotti, 1977; Karp et al., 1990) and midface (Rachmiel et al., 1993; Staffenberg et al., 1995) as well as results of human mandibular lengthening (McCarthy et al., 1992) demonstrate that distraction osteogenesis may play an important role in the treatment of craniofacial anomalies by creating new bone without the need for bone grafting. The purpose of this study was to perform multi-segmental lengthening of facial bones in different directions, as might be required for three-dimensional correction of facial anomalies. The hypothesis to be tested was that gradual distraction of multiple facial bone segments produces a more predictable result than acute surgical correction with bone grafts.