そしゃくにおける片側遊離端義歯装着の意義

Abstract

In some studies, the insertion of unilateral free-end removable partial dentures (RPDs) is regarded as overtreatment because mastication is not improved. However, most studies on masticatory efficiency have assessed only the degree of crushing and have disregarded the influence of RPDs on the intraoral flow of food, which is an essential factor for deglutition. In this study, two new parameters were devised to evaluate, at the same time, the degree of crushing and flow of the food, 10-mesh remaining ratio and lingual transport ratio, respectively.It was considered that patients who remove their RPDs chew unilaterally.Unilateral chewing was examined in seven fully dentate subjects (FDT group) first, and then in nine unilateral free-end RPD wearers (RPD group).In the FDT group, the degree of crushing and the accumulation of food particles in the lingual zone was significantly lower in unilateral chewing than in free chewing. In the RPD group, accumulation of food particles in the lingual zone was significantly lower without denture insertion than with the RPD inserted, but the degree of crushing was not significantly different.The results indicated that RPDs are useful for the accumulation of food particles in the lingual zone, which could facilitate deglutition.