Canadians missing five or more natural teeth face roughly a 76 per cent higher risk of being hospitalized for any cause and a 120 per cent higher risk of being hospitalized for circulatory-system diseases, according to a new Statistics Canada cohort study.
In line with previous global research on the mouth-body connection, the study suggests that tooth loss may serve as a meaningful indicator of overall health and health-service burden in adults aged 20 to 79.
The analysis drew on data from the Canadian Health Measures Survey (CHMS) Cycle 1 (2007-2009), which included direct clinical tooth counts, and linked them to the Canadian Vital Statistics – Death Database and the Discharge Abstract Database through 2019. The population-based sample included 3,454 participants in the mortality linkage and 2,252 participants in the hospitalisation linkage.
“This study is the first to provide time-to-event evidence on clinically measured oral health and its association with hospitalisation and mortality outcomes in Canada,” the authors wrote.
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The research team — Xue Feng Hu, Mohammad Moharrami and Janine Clarke of Statistics Canada’s Centre for Health Data Integration and Direct Measures, and Kellie Murphy of the agency’s Health Analysis and Modelling Division — conducted the analysis. Moharrami also teaches at the University of Toronto Faculty of Dentistry.
The authors described missing teeth as a “cumulative indicator of lifelong oral-health deterioration” and suggested it may function as a “simple, non-invasive marker” of broader health risk or service use. They noted that the association between missing teeth and hospitalisation remained strong across multiple sensitivity analyses.
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High certainty
The researchers quantified these risks using hazard ratios, a statistical measure estimating how much more likely an event is to occur in one group compared to another over time. In this study, adults missing five or more teeth had a hazard ratio (HR) of 1.76 for all-cause hospitalization and 2.20 for circulatory-system diseases, after adjusting for age, sex, smoking and diabetes. The 95 per cent confidence interval (CI) reflects the range within which the true value is expected to fall with high certainty — narrower intervals indicate greater precision.
Although the study found no major differences in tooth loss between men and women, it showed a progressive increase with age, with edentulism — complete tooth loss — remaining an important oral-health indicator.
Overall, the data from CHMS Cycle 1 showed that nearly half of Canadian adults (49.6 per cent) had no missing crowned teeth, while about one-quarter (26.3 per cent) had one to four missing crowns. Another 17.5 per cent had five or more missing crowns, and 6.4 per cent were edentulous.
Notably, rates of edentulism among Canadian adults have declined sharply: from 23.6 per cent in 1970-72 to 6.4 per cent in 2007-09, and further to 4.4 per cent in 2023-24, according to the report.
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Limitations and caveats
While the findings are robust for hospitalisation outcomes, the authors caution that:
- The sample excluded Quebec and Atlantic provinces, limiting national representativeness.
- The average 11-year follow-up period may still be too short for certain mortality analyses, meaning the absence of a statistically significant adjusted mortality link should not be interpreted as proof of no association.
- Tooth loss was treated as an indicator rather than a direct causal factor, and the authors noted that other unmeasured variables — such as nutrition, periodontal disease or socioeconomic status — could help explain the association. “Future studies could employ directed acyclic graphs and path analysis to further assess potential causal relationships and quantify direct, indirect, mediating and moderating effects,” the authors advised.