Image guided oral implantology and its application in the placement of zygoma implants

The application of zygoma implants proposes a successful treatment for functional reconstruction of maxillary defects. However, the placement of zygoma implants is not without risk due to anatomically complex operation sites. Aiming at minimizing the risks and improving the precision of the surgery, an image guided oral implantology system (IGOIS) is presented in this study to transfer the preoperative plan accurately to the operating theatre. The principle of IGOIS is introduced in detail, including the framework, 3D-reconstruction, preoperative planning, registration, and the motion tracking algorithm. The phantom experiment shows that fiducial registration error (FRE) and THE (target registration error) of IGOIS are, respectively, 1.12 mm and 1.35 mm. With respect to the overall accuracy, the average distance deviations at the coronal and apical point: of the implant are, respectively, 1.36 +/- 0.59 mm and 1.57 +/- 0.59 min, while average angle deviation between the axes of the planned and the actual implant is 4.1 + 0.9. A clinical report for a patient with a severely atrophic maxilla demonstrates that the major advantage of this computer-aided navigation technology lies in its accuracy, reliability, and flexibility. (C) 2008 Elsevier Ireland Ltd. All rights reserved.