An interactive method for computing tooth-root orientation from 3D CT image

In tooth implantation surgery, dentist or surgeon needs to derive quantitative information about the place each implant should be go, the length and width of each implant should be, as well as the angle each implant should be inserted, based on the 3D CT image of jaw of a patient. In existing techniques, the information is measured from such slices that are generated from virtually cutting teeth-ridge along the direction perpendicular to teeth-ridge. However, according to the clinical experience and anatomical knowledge, usually the largest length of each implant should be measured on such slice that is generated by cutting teeth-ridge along the tooth root direction. Besides, for each defect tooth, the most suitable angle or orientation to insert an implant is the tooth root orientation. Thus, in surgical planning of dental implant, it is much important to compute or estimate tooth root orientation from 3D CT image of jaw. To our knowledge, this problem is seldom studied in existing literature. In this paper, we try to discuss this problem.