Studies: Better Dental Health, Longer Life

Jiji Press

17:06 JST, January 16, 2026

TOKYO (Jiji Press) — Regular dental checkups and early treatment will help older people live longer, recent research studies have suggested.

Associations between the number of teeth and all-cause mortality have already been found, but little is known about dental conditions that should specifically be looked at to predict the incidence of death.

In their study, Naoko Otsuki, a lecturer at Osaka Metropolitan University, and team members including from the University of Osaka analyzed fiscal 2018-2020 dental checkup data collected from 190,282 residents aged at least 75 in Osaka, with particular attention to the number of sound, filled and decayed teeth.

The researchers first observed that elderly people having no teeth were 1.7 times more likely to die for whatever cause compared with those with 21 teeth or more. Then they found that the combination of sound and filled teeth can predict all-cause mortality more accurately than sound teeth alone or sound, filled and decayed teeth combined.

Death risks go down as the total number of sound and filled teeth increases, they concluded, warning that leaving dental problems untreated will result in higher risks.

In a separate study, an Institute of Science Tokyo-led team clarified that oral frailty, comprehensively defined by the team as fewer teeth, dry mouth and declining chewing, swallowing and speaking abilities, makes it harder for older people to live healthy lives longer.

Among 11,080 participants in the study with the mean age of 74.1, the healthy life expectancy at age 65 came to 23.39 years for men without oral frailty against 21.96 years with the condition. For women, the health expectancy stood at 24.77 years without oral frailty against 23.64 years with it.

Science Tokyo Prof. Jun Aida and colleagues also discovered that regular dentist visits extend healthy longevity by approximately one year regardless of sex and frailty status and that oral frailty sufferers have 1.23 times the chance of needing nursing care and 1.34 times the risk of dying compared with non-sufferers.

Noting that “chewing difficulty tends to lead to an unbalanced diet, low nutrition and weight loss,” Aida recommends regular checkups and early treatment of dental problems.