Two-step transport-disk distraction osteogenesis in reconstruction of mandibular defect involving body and ramus

One-step transport-disk distraction osteogenesis (TDDO) is effective for repairing segmental mandibular defects. The authors studied whether it was effective for reconstructing angled large mandibular defects using a two-step TDDO procedure in seven patients suffering from neoplasm. In the two-step TDDO procedure, the first distraction (horizontal distraction) was initiated immediately after mandibulectomy, aimed at restoring the mandibular body. It was followed by the second distraction, which was obliquely vertical and aimed at restoring the height of the ramus. The distraction rate was set at twice 0.4mm/day. The treatment lasted for 14-18 months. The horizontal distraction length ranged from 48 to 55mm, and the vertical one from 33 to 43mm, with full ossification in the distraction area. No obvious shift of mandible, malocclusion or mouth opening limitation was observed. Patients had a regular diet and spoke clearly. In conclusion, the two-step TDDO is still an option for the reconstruction of large angled mandibular defects when patients are prudently selected, despite the long treatment period required.