Comparison of three representative subjective evaluations of chewing function

In 2018, oral hypofunction was registered officially as a disease in Japan. It is important to detect oral hypofunction symptoms early in patients, before frank oral dysfunction symptoms occur. Subjective evaluations of chewing function, which help to identify foods that cannot be chewed, might be useful in diagnosing oral hypofunction. Previous evaluations used to identify patients with oral hypofunction used varying standards, making it impossible to compare and integrate them without first developing a unified screening method. This study aimed to compare and integrate known evaluation methods that are useful for diagnosing oral hypofunction. A total of 76 elderly participants （aged ＞65 years） were enrolled after providing consent to participate in this study. The established subjective evaluation methods of chewing function investigated for this study included the Yamamoto denture performance judgment table, the Sato table for evaluation of chewing function in complete denture wearers, and the Hirai evaluation method for the masticatory function in complete denture wearers. As the Yamamoto method lacks scoring, the total number of circles was used as the score. A time study was performed on the time taken for the description, entry, and analysis of these tables. There was a strong correlation between the Sato and Hirai methods （r＝0.71） and between the Sato and Yamamoto （r＝0.68） and Hirai and Yamamoto （r＝0.60） methods. During the time study, the description time was the shortest with the Yamamoto method, and the entry and analysis times were the shortest with the Sato method. The total time was significantly shorter with the Sato method than with the Yamamoto method. Three evaluation methods showed correlation, but the examination times varied. In future studies, we plan to clarify the selection criteria, including the relevance of objective evaluation and usability.