Dental health may be far more than a cosmetic or comfort issue in old age. New research from Japan suggests that the condition of an older adult’s teeth can offer important clues about their overall health, life expectancy and likelihood of requiring long-term care.
Two large-scale studies conducted by researchers at Osaka Metropolitan University and the Institute of Science Tokyo found strong links between poor oral health, higher mortality rates and increased dependence on nursing care among elderly populations. The findings add to a growing body of evidence that oral health plays a critical role in systemic health, particularly as people age.
One study, led by Osaka Metropolitan University, analyzed dental checkup data from more than 190,000 residents of Osaka Prefecture aged 75 and older. The participants underwent dental examinations between fiscal 2018 and 2020, allowing researchers to track patterns across a large and diverse population.
The team focused on the relationship between dental condition and all-cause mortality — deaths resulting from any cause. The results showed a clear trend: individuals with a greater number of healthy or properly treated teeth had lower death rates, while those with untreated cavities faced a significantly higher risk of mortality.
Researchers believe several factors may explain the connection. Poor oral health can make chewing difficult, leading to inadequate nutrition. Infections caused by untreated dental disease may also contribute to chronic inflammation, which has been linked to cardiovascular disease, diabetes and other serious conditions. In older adults, these risks are compounded by weakened immune systems and existing health problems.
The findings also have implications for long-term care planning. Declining oral health is often associated with reduced physical function and frailty, increasing the likelihood that older individuals will need assistance with daily activities or enter care facilities.
Taken together, the studies highlight the importance of routine dental care well into old age — not just to preserve quality of life, but potentially to extend it. Researchers stress that early treatment of cavities and proactive oral health management could serve as relatively simple interventions with meaningful public health benefits.
As Japan continues to grapple with the challenges of a rapidly aging population, the research underscores a key message: maintaining dental hygiene may be a powerful, and often overlooked, tool for supporting healthy aging and reducing the burden on healthcare and long-term care systems.