Abstract: Objective　 This paper reported a semi-digital technique to get an optimal fitting custom-made high-density porous Polyethylene (Medpor) for reconstruction of mandibular contour defects with the help of CAD/CAM and reverse engineering technology.Methods　17 patients suffered from defects of mandibular contour registered for the novel techniques adoption to reconstruct the mandibular contour. For each patient, computed tomography (CT) data were collected, CAD/CAM, reverse engineering and rapid prototyping (RP) by three-dimensional (3D) printing were used to fabricate the preoperative individualized geometric model. The mandibular contour defected areas were reconstructed by modelling and implanting Medpor.ResultsAll cases, except one with delayed infection whose implantation material was removed later on, recovered quite well. The follow-up observation showed that the previous defect zones had been accurately reconstructed, and a symmetric bony contour as well as an appealing facial appearance was acquired.Conclusions　Individualized Medpor implant based on CAD/CAM can accurately reconstruct defect of mandibular contour.

Key words: computer-aided design and manufacture（CAD/CAM）, rapid prototyping (RP), high-density porous Polyethylene (Medpor ), Defects of mandible