在可摘局部义齿的设计中,实验室研究虽能确定哪种卡环可使远中游离基托邻近的基牙移位最少,但临床实验资料却很少见。最近采用立体摄影测量术和电子计算机技术在(牙合)负载下测量基牙的位移,此方法可以在25μm水平三维空间内重复测定,本研究目的是将此法运 In the design of removable partial dentures, although laboratory studies can determine which snap ring can displace the abutment near the distal free abutment with minimal dislocation, clinical trial data are rare. Recently, the displacement of the abutments was measured under stereotactic load using stereophotogrammetry and computer technology. This method can be repeatedly measured in the three-dimensional space of 25 μm. The purpose of this study