Theoretical analysis of force distribution on lower partial dentures with symmetric saddles

Abstract

It is difficult to make direct measurements of the displacement of a partial denture as a function of the magnitude and direction of a force applied to the occulusive surface of the denture teeth during chewing. An indirect approach is possible, using a theoretical model in conjunction with some particular experimental measurements that are easier to make. The purpose of this paper is to present a theoretical linear model. The origin of the coordinate system is chosen at the tissue level under the center of the lower first molar. We first compute the total depth to which an arbitrary point on the ridge crest line will go when the denture is depressed into the ridge tissue during mastication. Using the approximation of linear depth force relationship, we find: A X=B where A is the shape and size coefficient matrix, B is the mastication-force column matrix, and X is the unknown column matrix which includes both the movement of reference points and the reactive force.