[Application of computer aided design/computer aided manufactured techniques in mandible defect reconstruction].

OBJECTIVE: To investigate the application of CAD/CAM technique in reconstruction of mandible defect. METHODS: Before surgery, three-dimensional computed tomography was performed in 23 patients with mandible lesions, then the CT data were transformed into a readable format to produce facsimile models by using rapid prototyping (RP) techniques. When individual mandibular models were produced, evaluation and surgical simulation were performed on the model, which included measuring range of mandible lesions, prefabrication of mandibular reconstructive titanium plates or distractors, ascertaining precise position of transport disk, and shaping the free vascularized fibula, etc. According to the simulation, the mandible reconstruction was accomplished in operation. RESULTS: The surgical simulation on the model produced by CAD/CAM technique highly resembled the real operation. The measurements of the lesion on the model were completely correspondent with those found in operation, and the prefabricated plates and distractor fitted the contour of the mandible. The operation time shortened and the results were satisfactory. The post-operation X-ray showed that the mandible was symmetrical and the maxillofacial contour maintained. CONCLUSIONS: CAD/CAM technique was very helpful for simulation of anatomically complicated mandible defect. By preoperative simulation of the mandible and lesions, surgeons are able to improve or refine surgical planning so that better results can be assured.