Tooth loss, swallowing dysfunction and mortality in Japanese older adults receiving home care services

Aim: Severe tooth loss and swallowing dysfunction occur more frequently in dependent older adult populations. Poor oral health and functional status are expected to have a negative impact on general health. We examined whether mortality is related to the number of teeth and swallowing function in dependent older Japanese individuals receiving home care services. Methods: Older adults aged ≥65 years who were receiving home care were included. The planned follow-up period was 3 years. Baseline data on the number of teeth, swallowing function, nutritional status, cognitive ability and activities of daily living were collected. Results: A total of 259 participants (mean age 85.0 ± 7.7 years) were enrolled. The mean length of follow up was 26.2 months. Severe tooth loss (≤9 present teeth) and swallowing dysfunction were observed in 68.0% and 32.0% of the participants, respectively. Cox's proportional hazards regression model showed that participants with both ≤9 teeth and swallowing dysfunction were at a higher risk of mortality compared with those with both ≥10 teeth and normal swallowing function (hazard ratio 2.89, 95% confidence interval 1.22–6.83). A significant interaction among severe tooth loss, swallowing dysfunction and mortality risk was observed. Conclusions: Severe tooth loss and swallowing dysfunction were associated with increased mortality. The present study suggests that the maintenance of oral health and swallowing function has a positive effect on general health. Therefore, attention should be given to both tooth loss and swallowing function in dependent older adult populations. Geriatr Gerontol Int 2018; 18: 873–880.