Influence of interocclusal distance of mandibular unilateral distal extension removable partial denture on masticatory function]

The purpose of this study was to elucidate the influence on masticatory function when the mandibular unilateral distal extension removable partial denture changed the interocclusal distance. The experiments, crushability, the sense of mastication, and the masticatory strokes until swallowing, were conducted, on four subjects, using the denture with the apparatus that enabled to change the interocclusal distance. The results were as follows: The particle size distribution showed that the ratio of small particle (diameter 2.5-4.5 mm) decreased, while that of large particle (more than 5.0 mm) increased, on three of four subjects, and the value of crushability diminished. A reduction of the value of crushability when the interocclusal distance was extended more than 800 microns was found. As for the other subject, no change was recognized on the particle size distribution under experimental condition, and the value of crushability showed no significant change.