Abstract
Esthetic improvement of the face is one of the goals of orthognathic surgery. When attempting to make an objective evaluation of the profile as a result of the surgery, soft tissue measurements on a lateral cephalometric radiogram are currently used, which are compared with the norm. However, no single measurement provides an overall evaluation of the profile esthetics. Contrarily a subjective impression by eye gives a comprehensive evaluation, although there is a problem which can not be quantified due to its intrinsic fuzziness. Then we applied the fuzzy reasoning to modelling a subjective evaluation of profile and have developed a computer system (prototype).
