RESUMO
<p><b>OBJECTIVE</b>To investigate the application of double-step distraction osteogenesis in the reconstruction of mandibular segmental defects after tumor resection.</p><p><b>METHODS</b>From January 2002 to December 2006, six cases of post-tumor unilateral mandibular segmental defects were reconstructed using distraction osteogenesis. The mandibular body was lengthened first, following by mandibular ramus distraction.</p><p><b>RESULTS</b>No infection or other complication was observed. The maximal distraction length reached 55 millimeter in the mandibular body, and 42 millimeter in the mandibular ramus. The average distraction length was 52 millimeter in the mandibular body, and 34 millimeter in the mandibular ramus. Both the aesthetic and functional result was excellent in all cases.</p><p><b>CONCLUSIONS</b>Double-step distraction osteogenesis is effective and easily performed in the reconstruction of unilateral mandibular segmental defects with less morbidities and complications. There is no need for donor site. However, the treatment period is relatively long with three staged operations.</p>