A chairside analysis of the feasibility of selective grinding

A rationale has been suggested for obtaining numerical values indicating the difficulty in reconciling RCP with IC. This approach makes a distinction between translation and rotation of the hinge axis as the mandible moves from RCP to IC. To differentiate translation from rotation, a comparison is made between the horizontal and vertical components of the slide. To determine the difficulty in reconciling RCP with IC, a comparison has been suggested between the angle of deflection of the slide (tan d = H/V), or its numerical inverse ratio (V/H), to the approximate angle of closure from RCP (34 degree +/- 4 degree) which has a ratio of 1.48. It has been suggested that an approximate angle of displacement of over 45 degree or a ratio of 1 or less acting over a significant distance between RCP and IC, may need further study before occlusal adjustment by selective grinding is attempted. The limitations and some ramifications of the geometric analysis were presented. Further studies are necessary to determine the error of the method.