Association among the number of teeth, dental prosthesis use, and subjective happiness: A cross-sectional study from the Japan Gerontological Evaluation study (JAGES).

Statement Of Problem: Little is known about the association between the number of teeth and self-rated happiness or the association between dental prosthesis use and self-rated happiness in an older population.

Purpose: The purpose of this cross-sectional study was to examine the association between the number remaining of teeth with and without dental prosthesis use and self-rated happiness in an older population.

Material And Methods: The survey data from the 2016 Japan Gerontological Evaluation Study (JAGES) on independent participants aged 65 years or older were assessed. The Poisson regression and multiple imputation methods were used for analyses. Covariates were age, sex, marital status, educational attainment, self-rated health, self-rated economic situation, and symptoms of depression.

Results: The data from 178 090 participants, 81 489 men (45.8%) and 96 601 women (54.2%), were analyzed, with a mean ±standard deviation age of 73.6 ±6.1 years. Overall, 66.4% of the participants were happy, declining to 45.7% in those who had 0 to 9 teeth and no dental prosthesis (n=3102). It was 61.5% in those who had 0 to 9 teeth and used a dental prosthesis (n=41 424), 56.8% in those who had 10 to 19 teeth and no dental prosthesis (n=6719), 65% in those who had 10 to 19 teeth and used a dental prosthesis (n=31 592), 70.5% in those who had ≥20 teeth and no dental prosthesis (n=52 525), and 70.1% in those who had ≥20 teeth and used a dental prosthesis (n=42 728). The interaction analysis showed that the reduction in the probability of being happy among those with fewer teeth was smaller among those who used a dental prosthesis.

Conclusions: Having a higher number of teeth and using a dental prosthesis were independently associated with being happy. A significant interaction suggested that dental prosthesis use improves happiness among those with moderate to severe tooth loss (<20 remaining teeth).