Fracture or defect of the mandible is a serious complication of mandibular angleplasty, and precise reconstruction for such defect is still a huge challenge. This case report provides a new method based on CAD/CAM and rapid prototyped titanium for individual design, fabrication, and implantation of a mandibular ramus and angle. A 25-year-old woman with a square-shaped face, who had undergone mandibular outer cortex split ostectomy (MOCSO) 3 months earlier, was afflicted by a series of symptoms: asymmetric face, collapse of the right face, masticatory problems, deviation during mouth opening, malocclusion, and TMJ clicks. These symptoms were caused by unintentional removal of the fractured ramus during MOCSO. By means of CT scan data, rapid prototyping, reverse engineering, 3D display, and CAD/CAM, the individualized titanium implant was designed and fabricated. The 3D demo system of operative scheme demonstrated the operative procedure, and determined the position of the implant so as to obtain a perfect fit. Postoperatively, the patient regained satisfactory morphologic symmetry, facial appearance, occlusion, and TMJ functions.