[Computer-aided design in double-step distraction osteogenesis of unilateral mandibular segmental defects reconstruction].

Objective: To investigate the feasibility of using computer-aided design (CAD) in double-step distraction osteogenesis in the reconstruction of mandibular segmental defects after tumor resection.

Methods: Eight cases of unilateral mandibular segmental defects were reconstructed using distraction osteogenesis secondary to oncologic surgery, with the help of CT and CAD system. The mandibular body was lengthened first, and then the residual defect of mandibular ramus was restored using a distraction device.

Results: No incidence of infection or other complications were observed. The maximal amount of the lengthening reached 55 mm in the mandibular body, and 45 mm in the mandibular ramus. The average amount of the lengthening reached 49 mm in the mandibular body, and 36 mm in the mandibular ramus. The aesthetic and functional results of bone lengthening were excellent in all cases. The retractor was removed eight months postoperatively.

Conclusions: Using CAD in double-step distraction osteogenesis in the reconstruction of unilateral mandibular segmental defects has the advantages of precise diagnosis, operation planning and assuring success of operation. It has the disadvantage of a long period for the overall treatment time.