Dental health and longevity

[Examination of correlation between medical expenses with average life expectancy according to municipality and gender]

OBJECTIVES

To determine the influence of medical expenses on life expectancy.

METHODS

The expenses of 1,718 municipalities were divided into total expenses, hospitalization expenses and expenses other than hospitalization and dental expenses. 1) The correlation of life expectancy with sex was considered. 2) The correlation between expenses and life expectancy was considered. 3) The correlation of life expectancy or expenses with the numbers of doctors, dentists, facilities and beds was considered. 4) Using the Mahalanobis-Taguchi method, a unit space was formed by 10 municipalities with a high life expectancy, and D(2) was calculated. When D(2) was outside the unit space, the expenses were not as much as those of the 10 municipalities with a high life expectancy.

RESULTS

1) Life expectancy showed a positive correlation with gender. 2) Male life expectancy showed a negative correlation with total and hospitalization expenses, and a positive correlation with dental expenses. A positive correlation was found between each of expenses and female life expectancy. Total expenses, hospitalization expenses and expenses other than those on hospitalization showed a negative correlations with life expectancy in Hokkaido. Dental expenses showed a negative correlation with life expectancy in Chubu, hospitalization expenses showed a negative correlation with life expectancy in Kyushu. Total, hospitalization and dental expenses showed positive correlations with life expectancy in Tohoku, and dental expenses showed a positive correlation with life expectancy in Kanto and Chubu. 3) Total expenses, hospitalization expenses and expenses other than those on hospitalization were found to correlate with the number of doctors. Dental expenses were found to correlate with the numbers of doctors, facilities, and beds. 4) The difference in among estranged municipalities was considered. Life expectancy was significantly short in estranged municipalities, and the total expenses and hospitalization expenses were large.

CONCLUSIONS

The relationship of medical expenses with life expectancy became clear. It was assumed that medical performance was poor in estranged municipalities.

Critical tooth number without subjective dysphagia

AIM

To assess the critical tooth number (CTN) required for prevention of subjective dysphagia caused by oral impairments and to evaluate the relationship between this CTN and mortality.

METHODS

The baseline study was performed with residents aged 40-89years (n=5,643; 2224 men and 3419 women) in Miyako Islands, Okinawa, in 1987. Dental examinations were performed by dentists, and subjective dysphagia was asked. We recorded the cause and year of death of participants who died during the next 15years.

RESULTS

The average functional tooth number of participants with and without subjective dysphagia declined with age in both sexes. The CTN for each respective age group (40s, 50s, 60s, 70s and 80s) not including the denture group were 20.0, 17.5, 14.0, 11.8 and 10.1 in men and 19.0, 14.7, 12.7, 9.5 and 4.0 in women. These CTN were significant factors of 15-year mortality in both sexes (P<0.05). The hazard ratios were 0.72 (95% confidence interval=0.55-0.93) in men and 0.71 (0.51-0.99) in women.

CONCLUSION

  In aged people, the minimum number of functional teeth needed to avoid subjective dysphagia might not be as high as in young people.