Abstract
In this study, the author discussed the necessity of a facebow on the articulator which can reproduce forward movement of human jaw and conducted a geometrical analysis ofcompensating curve. Being against the use of a facebow, the author mathematically defined compensating curve which have not been determined accurately. Once centric occlusion obtained, the position of the jaw set in the articulator is exclusively related to the movement of the jaw and maintains the movement that are ideatical to those of the jaw by the use of check-bite. Therefore, the positions of the articulator joints( center of the calibration plate and anterios guide table) does not have to correspond to that of the condyle head. There is no need to use a facebow. On the other hand, since the inclination of the movement path of the articulator is determined when the occlusion plane of the articulator is positioned, the occlusion plane of the occlusion rim should correspond to that of the articulator. In other words, it is more logical to use the occlusion plane table for setting.
In addition, with the length of the occlusion rim being a chord, compensating curve is on the circumference of the circle containing difference between the movement path of forward and backward ends of the occlusion rim on the occlusal plane table.
