OBJECTIVES: To estimate the impact of explicit fluoride-related language in prefectural dental health ordinance on the dissemination of school-based fluoride mouth-rinse (S-FMR) programs. METHODS: A longitudinal ecological design was employed to analyze prefectural-level panel data from Japan spanning 2007 to 2018. Ordinances enacted between 2010 and 2014 were categorized by the presence of explicit fluoride-related terms: 1) explicit mention of "fluoride mouth-rinse" (FMR group); 2) explicit mention of "fluoride application" (FA group); and 3) no fluoride-related policy language (NF group). The outcome was the proportion of children aged 4-15 years participating in S-FMR programs. Total prefectural income per year, prefectural mean age, and prefectural mean number of decayed, missing, or filled primary teeth (dmft) among 3-year-old children were included as covariates. The Callaway and Sant'Anna Difference-in-Differences (CSDID) method was applied to estimate the average treatment effects on the treated (ATT) for the FMR and FA groups under a conditional parallel trends assumption. RESULTS: A total of 39 prefectures were analyzed. The pre-post increase in S-FMR participation was greater in the FMR group than in the FA or NF groups, with comparable differences (FMR: 12%; FA and NF: 5% each). In the CSDID analysis, both the FMR and FA groups showed a significant increase in S-FMR participation compared with the NF group, with a larger effect in the FMR group [FMR: 8% (95% CI: 2%-15%); FA: 5% (95% CI: 0%-9%)]. The event-study estimates indicated that the effects strengthened over time, particularly in the FMR group. CONCLUSIONS: Prefectural dental health ordinances explicitly refer to fluoride, particularly FMR, are associated with a greater dissemination of the proportion of children participating in S-FMR programs. These findings suggest that more specific and explicit policy language in dental health ordinances may enhance the dissemination of S-FMR programs.

OBJECTIVE: Cardiovascular health (CVH), defined by the American Heart Association, aims to reduce cardiovascular disease (CVD) deaths and improve overall health. Poor oral health, including tooth loss, is increasingly linked to higher CVD risk. However, the effects of specific partial tooth loss patterns on CVH remain unclear. This study aimed to identify clinically relevant tooth loss patterns and evaluate their association with CVH in a large Japanese population. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Health insurance claims data were obtained from the JMDC database between 2016 and 2019. The study included 215,750 adults aged 40-75 years who had at least 20 remaining teeth and underwent both dental and general health examinations. METHODS: CVH scores were calculated based on 4 behavioral metrics (smoking status, body mass index [BMI], physical activity, and dietary habits) and 3 biological metrics (blood pressure, fasting glucose, and total cholesterol), following American Heart Association guidelines. K-median clustering was applied to identify patterns of partial tooth loss. Associations between tooth loss patterns and CVH scores were analyzed using fixed-effects models, including sex-stratified analyses. RESULTS: Six distinct partial tooth loss patterns were identified, including maxillary and mandibular molar loss, unilateral molar loss, and minor anterior tooth loss. Compared with individuals with all 28 teeth, those with partial tooth loss exhibited significantly lower CVH scores. The greatest reduction was observed in the maxillary molar loss group (β = -0.28; 95% CI, 0.34 to -0.22). Sex-stratified analyses showed that the associations were stronger in women than in men. Partial tooth loss was more strongly associated with behavioral metrics, particularly BMI and dietary habits, than with biological metrics. CONCLUSIONS AND IMPLICATIONS: Specific partial tooth loss patterns, especially molar loss, were associated with poorer CVH scores. These findings underscore the importance of preserving molar occlusion and integrating dental and cardiovascular prevention.

OBJECTIVES: Social isolation and loneliness each have negatively affect various health outcomes. No studies have examined the combined association of social isolation and loneliness on frailty onset. This study aimed to investigate both the objective and subjective aspects of isolation by evaluating social isolation and loneliness and to determine their interaction effects on frailty onset. METHODS: This cohort study used data from the 2019 and 2022 Japan Gerontological Evaluation Study. The eligible participants were independent older adults aged ≥65 years without frailty in 2019. The outcome variable was frailty onset in 2022. The exposure variables were social isolation and loneliness in 2019. Risk ratios (RR) and 95 % confidence intervals (CI) were estimated using modified Poisson regression models, with potential confounders as covariates. Moreover, a multiplicative scale and relative excess risk due to interaction (RERI) was used to assess the interaction. RESULTS: The analysis included 8440 participants (mean age: 73.2 [standard deviation, 5.5] years). During the follow-up, 15.1 % of participants experienced frailty onset. After adjusting for all covariates, the "severe isolation" & "severe loneliness" group had the highest risk of frailty onset (RR = 2.09 [95 % CI: 1.60-2.73]) compared to "no isolation" & "no loneliness" group. However, there were no significant multiplicative and additive interaction between social isolation and loneliness on frailty onset (multiplicative scale: 0.75 [95 % CI: 0.50-1.11]; RERI:0.29 [95 % CI:1.02-0.44]). DISCUSSION: These findings highlight the importance of considering social factors such as interaction with others and loneliness, to prevent frailty.

PURPOSE: To investigate the association of removable partial denture (RPD)/complete denture (CD) and fixed partial denture (FPD) use with health-related quality of life (HRQoL), evaluated using the EuroQol 5-dimension, 5-level instrument (EQ-5D-5L) among older adults with tooth loss. METHODS: Cross-sectional data from the 2022 Japan Gerontological Evaluation Study. Participants were classified as RPD/CD users, FPD users, or nonusers. Generalized linear regression models stratified by the number of teeth were used to explore the association of RPD/CD and FPD use with the HRQoL evaluated using the EQ-5D-5L. The interactions among the number of teeth, RPD/CD, and FPD use were examined. RESULTS: After adjusting for all covariates, RPD/CD and FPD users with 5-19 teeth had higher predicted HRQoL utility scores than nonusers (RPD/CD [n=14,297]: 0.837 vs. 0.850; FPD [n=7,476]: 0.858 vs. 0.861 [nonusers vs. users]). The interaction between number of teeth and RPD/CD and FPD use revealed that differences in HRQoL between users and nonusers were greater among those with 1-14 teeth for RPD/CD use and among those with 10-14 teeth for FPD use (RPD/CD: β = -0.008, P < 0.01; FPD: β = -0.008, P = 0.183). CONCLUSIONS: RPD/CD and FPD users with 5-19 teeth had a higher HRQoL than nonusers, with differences appearing to depend on the number of teeth. The World Health Organization has promoted the incorporation of oral health into universal health coverage (UHC). Given the minimal HRQoL difference between CD users and nonusers among edentulous individuals, unconventional dentures may merit inclusion in UHC.