Analysis of the relationship between cognitive impairment and oral oral hypofunction in health checkups of elderly Japanese residents

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K19311
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57080:Social dentistry-related
• Research Institution: Kanazawa University
• Principal Investigator: Ishimiya-Jokaji Mai 金沢大学, 附属病院, 医員 (70834620)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 社会歯科学 / 口腔機能低下 / 認知機能低下

Outline of Final Research Achievements

This study explored the relationships among oral functionality, dietary consumption, cognitive decline, and dementia in a cohort of 919 elderly Japanese individuals in Nakajima, Ishikawa Prefecture, Japan. Cognitively normal individuals with less than 10 teeth had significantly smaller volumes of the parahippocampal gyrus, superior parietal cortex, middle temporal gyrus, lingual cortex, and bankssts and a greater WMH volume than those with the most residual teeth (highest tertile). This suggests that tooth loss, even in cognitively normal individuals, is associated with atrophy of the parahippocampal gyrus and greater WMH volume, which are both characteristics of dementia.

Free Research Field

口腔外科学

Academic Significance and Societal Importance of the Research Achievements

認知機能低下と口腔機能低下との関連について調査した研究はこれまでに存在するが、認知機能についてはMMSEやHDS-Rを用いて簡易的に評価されたものが多かった。本研究では被験者の頭部MRIが撮影され、脳神経内科医師により認知症やMCIについての診断が行われ、同時に口腔機能検査が行われているという点において貴重なデータを得ることができたと思われる。今後は因果関係を明らかにするために追跡調査が必要と考える。