A planning system for oral implant surgery based on a true three-dimensional approach is described. This system allows the interactive placement and adjustment of axial-symmetric models representing implants in the jawbone structures visible on computerized tomographic volume data. Simultaneous visualization is possible on two-dimensional reformatted images and on three-dimensional-derived bone surface representations. This approach largely outperforms the manual planning practice based on two-dimensional dental computerized tomographic images printed or on film. Keywords: computer-assisted surgery, computerized tomography, dental implant, OpenGL, preoperative planning