Real-time motion tracking in image-guided oral implantology.

BACKGROUND As a crucial part of an image-guided oral implantology system (IGOIS), intra-operative motion tracking is important in terms of accuracy and efficiency. The tracking method, including the relevant algorithms, is described in detail. METHODS The conventional CAD method is proposed to build the three-dimensional (3D) surgical instrument models. With the application of the optical tracking device, calibration can be carried out. Three tracking algorithms are presented, and 'tracking based on registration of RCS to VCS' is regarded as the most efficient of these. In order to evaluate the tracking accuracy, the landmark coordinates are respectively obtained through pre-operative CT data and intra-operative tracking, so that the deviation can be calculated. RESULTS The result data reveal that FRE and TRE of IGOIS are, respectively, 0.27 +/- 0.11 mm and 0.77 +/- 0.04 mm through a phantom experiment. CONCLUSIONS The experiment demonstrates the accuracy and reliability of IGOIS. The tracking method can be extended to other surgical navigation systems in various areas.