Oral function as an indexing parameter for mild cognitive impairment in older adults

To investigate the association between mild cognitive impairment (MCI) and oral status, and to develop an oral-based screening index for MCI.

A cross-sectional study was carried out in a total of 5104 community-dwelling adults (aged ≥65 years) from the Obu Study of Health Promotion for the Elderly. Screening for MCI included a standardized personal interview, Mini-Mental State Examination, Geriatrics and Gerontology-Functional Assessment Tool (which included 8 tasks used to assess logical memory, word list memory, attention and executive function, processing speed, and visuospatial skill) and oral status.

In our study, 930 individuals were diagnosed with MCI, whereas the remaining 2669 were not. Both men and women with MCI showed a significantly lower number of functional and present teeth, poorer oral diadochokinesis, and less palpation of masseter muscle tension (P < 0.01). Discriminant analysis of participants with MCI, between categories of pertinence and non-pertinence, showed significant associations for age, sex, educational background, handgrip strength, Geriatric Depression Scale score, Mini-Mental State Examination score, history of heart disease, albumin level and oral diadochokinesis representing oral motor skill. Although the diagnosis rate of our screening index for MCI was not high, it was in the acceptable range as a screening index.

Oral motor skill, such as lip movement, might be impaired in patients with MCI. Detecting decreasing oral motor dexterity supports the early detection of MCI, and might be key to improve the prognosis of dementia. Geriatr Gerontol Int 2018; 18: 790-798.