ファジィ推論による顎矯正術後の軟組織側貌の予測(一般講演2-画像診断-)

抄録

In the presurgical work-up of orthognathic surgery, a resultant profile is predicted on a lateral cephalogram. Several hard to soft tissue ratios or linear regression formulas are available to predict a change of soft tissue landmark. But the change in nasolabial region is unpredictable with linear formulas. Because the change is a nonlinear result of the interaction of some factors, including elasticity of the nasal cartilage, tissue thickness and tonicity, and the bony movement. The aim of this paper is to demonstrate a prediction system employing the fuzzy inference.Materials were 40 lateral cephalograms taken before and six months after surgery of twentybimaxillary orthognathic surgery cases. The change of point "Pronasale" was tested for fuzzy prediction system. The system showed high correlation between actual and predicted values and coefficient was 0.94. Errors ranged from -0.6mm to 0.5mm with standard error 0.35. Therefore, the fuzzy prediction system is available for a clinical use.