[Relation between articulatory function and prosthesis. I-1. Longitudinal changing aspects in the duration of speech sound, muscular discharge of facial muscle and tongue pressure before pronunciation caused by the experimental palatal plate].

The author noticed the relation between articulatory functions and the prosthesis. For the purpose of clarifying the influence of the insertion of denture on the duration of speech sound and the articulatory functions before pronunciation and on the self-compensation of these organs. The experimental palatal plates were inserted on 13 subjects with natural dentition, assuming that they were inserted with complete denture, and the duration of speech sound, muscular discharge of facial muscle and tongue pressure before pronunciation were evaluated longitudinally with the pre-insertion of palatal plate as basis. As the result of this study, the following conclusions were obtained. The results of this study suggest that speech sound, lips and tongue being important organs as the articulators are placed under strong influence before pronunciation by insertion of the denture, whereas on the self-compensation of the articulators before pronunciation differed according to the point of articulation and the manner of articulation of each speech sound. Therefore, it was necessary to take care on the relation between the shape of palatal plate and the articulatory functions of lips and tongue in the clinical prosthodontics.