下顎片側遊離端欠損症例における垂直荷重時の義歯床の回転

Abstract

In function, the movement of removable partial denture in various directions is caused by biting force or masticatory force. For free-end saddle denture, these movements are known to have a bad influence on abutment teeth or residual ridges.For denture retention and stability and for protecting supporting tissues, movement should be kept as small as possible.In this study, by focusing on the artificial teeth arrangement procedure which minimizes denture movements in function, it was attempted to establish a method of measuring lower unilateral denture base movement under loading and of analyzing it as rotation with a three-dimensional 6-degree comparator.The results were as follows: 1. An angle of denture base rotation on the horizontal plane (Yawing) tended to be smaller than that on the frontal plane (Rolling) and on the sagittal plane (Pitching). The loading position had little influence on the angle of Yawing. 2. Empirical equations, which express the angle of Rolling and Pitching, were obtained from the investigation of the relation between the denture base movement and the loading position in the frontal sections of the residual ridge. These results suggested that the position of artificial teeth on the residual ridge, which control the denture base movement, could be estimated by using these equations.