Piehslinger E, Bauer W, Schmiedmayer H B
Department of Fixed and Removal Prosthodontics, University of Vienna, Austria.
J Prosthet Dent. 1995 Sep;74(3):279-83. doi: 10.1016/s0022-3913(05)80135-0.
The effect of arbitrary mounting of maxillary casts on occlusal relationships was investigated in this study. Maxillary casts of 31 volunteers were mounted on an articulator by use of two split cast bases. This mounting was done first with the arbitrary face bow and second with a hinge bow. Three reference points were defined and measured on each maxillary cast with a three-dimensional digitizer. The measurements were taken from the arbitrarily mounted cast and from the cast mounted according to the hinge axis. Opening and closing movements that were transferred according to the hinge axis. Opening and closing movements that were transferred from the articulator to the mouth of the patient were simulated by a computer based on measurements of the reference points. The results revealed that the use of an arbitrary face bow causes a deviation of the hinge-axis points from the precise axis of more than 5 mm in 77% of the cases. Resulting occlusal errors depended on the angles between the arbitrary and precise axes and the direction of the axis shifts. The occlusal error is roughly proportional to the shift or tilting of the hinge axis in millimeters or degrees. For a given deviation of the arbitrary and precise axes, the occlusal error is proportional to the record height. For a record height of 2 mm or more, an occlusal error of more than 0.1 mm will occur. An average occlusal error of more than 0.1 mm would most likely lead to the necessity of extensive selective grinding of occlusal discrepancies in the patient's mouth.
本研究调查了上颌模型任意上架对咬合关系的影响。使用两个分体模型底座，将31名志愿者的上颌模型安装在牙合架上。首先使用任意面弓进行这种上架，其次使用铰链式面弓。用三维数字化仪在上颌模型上定义并测量三个参考点。测量取自任意上架的模型以及根据铰链轴上架的模型。根据铰链轴传递开闭运动。基于参考点的测量，通过计算机模拟从牙合架传递到患者口腔的开闭运动。结果显示，在77%的情况下，使用任意面弓会导致铰链轴点偏离精确轴超过5毫米。产生的咬合误差取决于任意轴与精确轴之间的角度以及轴偏移的方向。咬合误差大致与铰链轴在毫米或度数上的偏移或倾斜成正比。对于任意轴与精确轴的给定偏差，咬合误差与记录高度成正比。对于2毫米或更高的记录高度，将出现超过0.1毫米的咬合误差。平均超过0.1毫米的咬合误差很可能导致需要在患者口腔中对咬合差异进行广泛的选择性研磨。
