Periodontal Disease and Healthcare Expenditures: A 7-Year Cohort Study of Employees in Japan

Background: The global economic burden of dental diseases, particularly periodontitis, is substantial, with growing evidence linking these conditions to systemic diseases such as diabetes and cardiovascular diseases. Although international studies have demonstrated that periodontal treatment can mitigate medical costs, comprehensive research examining the relationship among oral health, healthcare expenditures, and systemic disease inset is still scarce, particularly in Japan. Therefore, this study examined the associations among oral health, medical and dental expenditures, and the incidence of lifestyle-related diseases, using annual health checkup data. Methods: This long-term cohort study analyzed data from 467 male employees who participated in annual health and dental check-ups from 2009-2014. Participants were categorized into periodontitis and non-periodontitis groups based on the community periodontal index. We compared baseline characteristics and healthcare expenditures (medical, dental, pharmaceutical and total healthcare) between two groups. Longitudinal changes in glycated hemoglobin (HbA1c) levels were evaluated using a mixed model for repeated measures. Results: Participants in the periodontitis group (n=87) was significantly older than the non-periodontitis group (n=380). Median annual medical expenditure (¥41,160 vs ¥21,770; p=0.03), dental expenditure (¥12,760 vs ¥7,030; p=0.01), and total healthcare expenditure (¥97,030 vs ¥51,415; p=0.002) were significantly higher in the periodontitis group. No significant difference in HbA1c trajectories or the risk of exceeding an HbA1c threshold of 5.6% or 6.5% was observed between the two groups. Conclusion: Poor periodontal health is associated with increased medical and dental expenditures. Promoting oral health in the workplace may be a cost-effective strategy for reducing the overall healthcare burden.