of post-surgical morbidity by avoiding accidental damage to adjacent centers. Computer-assisted neurosurgery also includes spinal procedures using navigation and robotics systems. Current navigation systems available include Medtronic Stealth, BrainLab, 7D Surgical, and Stryker; current robotics systems available include Mazor Renaissance, MazorX, Globus Excelsius GPS, and Brainlab Cirq. Computer-assisted oral and maxillofacial surgery Bone segment navigation is the modern surgical approach in orthognathic surgery (correction of the anomalies of the jaws and skull), in temporo-mandibular joint (TMJ) surgery, or in the reconstruction of the mid-face and orbit. It is also used in implantology where the available bone can be seen and the position, angulation and depth of the implants can be simulated before the surgery. During the operation surgeon is guided visually and by sound alerts. IGI (Image Guided Implantology) is one of the navigation systems which uses this technology. Guided Implantology New therapeutic concepts as guided surgery are being developed and applied in the placement of dental implants. The prosthetic rehabilitation is also planned and performed parallel to the surgical procedures. The planning steps are at the foreground and carried out in a cooperation of the surgeon, the dentist and the dental technician. Edentulous patients, either one or both jaws, benefit as the time of treatment is reduced. Regarding the edentulous patients, conventional denture support is often compromised due to moderate bone atrophy, even if the dentures are constructed based on correct anatomic morphology. Using cone beam computed tomography, the patient and the existing prosthesis are being scanned. Furthermore, the prosthesis alone is also scanned. Glass pearls of defined diameter are placed in the prosthesis and used as reference points for the upcoming planning. The resulting data is processed and the position of the implants determined. The surgeon, using special developed software, plans the implants based on prosthetic concepts considering the anatomic morphology. After the planning of the surgical part is completed, a CAD/CAM surgical guide for dental placement is constructed. The mucosal-supported surgical splint ensures the exact placement of the implants in the patient. Parallel to this step, the new implant supported prosthesis is constructed. The dental technician, using the data resulting from the previous scans, manufactures a model representing the situation after the implant placement. The prosthetic compounds, abutments, are already prefabricated. The length and the inclination can be chosen. The abutments are connected to the model at a position in consideration of the prosthetic situation. The exact