Trends in dental expenditures in Japan with a universal health insurance system.

BACKGROUND: The government of Japan has spent a significant amount on dental healthcare, but it remains unknown how the spending varies across age, type of service, and time. This study describes trends in dental expenditures in Japan. METHODS: This descriptive study used two national data sources: Estimates of National Medical Care Expenditure and Survey on Economic Conditions in Health Care. We obtained annual total and average per capita dental expenditures by age in Japan from 1984 to 2020 and estimated the proportions of types of service from 1996 to 2021. All costs were adjusted for the 2020 Consumer Price Index (1 US dollar ≈ 100 yen in 2020). RESULTS: Total dental expenditures increased from 1.96 trillion yen in 1984 to 3.00 trillion yen in 2020. In particular, total and average per capita dental spending for older persons showed a rapid increase (total: from 185 billion yen in 1984 to 1.18 trillion yen in 2020; average per capita: from 15,500 yen in 1984 to 32,800 yen in 2020), contributing to the total amount increase. The crown restoration and prosthesis category amounted to 50.3% of the total expenditure in 1996, and this proportion declined to 32.4% by 2021. In 0-14 years persons, expenses on the crown restoration and prosthesis category decreased while the medical management category (mainly including fees for a management plan for oral diseases or oral functions) increased. In persons aged 65 years or older, expenses on the crown restoration and prosthesis category decreased, with increasing expenses in the medical management and at-home treatment categories. CONCLUSION: The amount of dental spending in Japan substantially increased from 1.96 trillion yen in 1984 to 3.00 trillion yen in 2020), a 1.53-fold increase. The observed changes in annual dental spending varied across age groups and types of service.

Policies Supporting Oral Health in Ageing Populations Are Needed Worldwide.

This literature review examines the need to develop appropriate policies specific to the oral health needs of older people that are individualised, cost-effective, and sustainable. Poor oral health and impaired oral function negatively affect the health and quality of life of older adults. Developing care systems that aim to meet patients' normative needs as well as their perceived needs and expectations is one factor in successful delivery of appropriate dental care. Cost is another significant driver of utilisation, and many older adults worldwide lack adequate resources for dental care. Failure to address these issues results in poor outcomes and increased costs of dental and medical care. Disease prevention and control at early stages can preserve public and private financial resources as well as quality of life and well-being for older adults at any stage of life.

Periodontal health predicts self-rated general health: A time-lagged cohort study.

OBJECTIVES: There is limited evidence of a temporal relationship between periodontal diseases and self-perceived general health. To plug this knowledge gap, we aimed to assess how periodontal health affects future self-rated health (SRH). METHODS: We collected data from five waves of an annual nationwide Japanese survey of dental patients from 2015 to 2019. The analysis of repeated measurements included 9306 observations from 4242 patients aged 20 years or older. The clinical periodontitis measurements were bleeding on probing, deepest periodontal pocket depth and most severe clinical attachment loss (CAL). We used a self-administered questionnaire to collect data on sociodemographic characteristics, diabetes history, health behaviour, SRH and self-reported periodontitis. We applied 2-level ordered logistic regression models for repeated measurements to examine the relationships between SRH (time t) and 1-year-lagged periodontal health (time t-1) after adjusting for covariates. RESULTS: The percentage of SRH responses recorded at time t as 'good', 'moderate' and 'poor' were 36.9%, 52.4% and 10.7%, respectively. Multivariate analyses showed that the risk of poorer SRH at time t increased in patients with CAL ≥7 mm (odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.02-1.30), those who reported bleeding gums (OR = 1.33, 95% CI = 1.21-1.46) and those who perceived swollen gums (OR = 1.40, 95% CI = 1.26-1.56) at time t-1. Sensitivity analyses using the 4-year follow-up model and 3-year-lagged cohort model also showed consistent results. CONCLUSION: Periodontitis shows a gradual contribution to future SRH in dental patients, even after adjusting for sociodemographic characteristics, general health and health-related behaviours.

Multilevel Analysis of the Association of Dental-Hygienist-Related Factors on Regular Dental Check-Up Behavior.

Few studies have examined the factors related to dental clinics during dental check-ups. We examined the association between dental-hygienist-related factors and patients' regular dental check-ups. This nationwide cross-sectional study was based on a survey conducted in Japan in 2014. The analyzed population included 12,139 patients from 1181 dental clinics. We used three-level Poisson regression analysis, considering patient‒clinic‒prefecture, to examine the association of dental-hygienist-related factors with dental check-up behavior. Patients attending treatment and regular check-ups constituted 63.0% and 37.0%, respectively. The adjusted prevalence ratios (PRs) for patients undergoing regular dental check-ups at dental clinics with dedicated dental hygienists' units, spending ≥20 min in patient education (compared to 0 min), and with three or more dental hygienists (compared to 0 hygienists) available were 1.17 (95% confidence interval [CI]: 1.06-1.30), 1.25 (95%CI: 1.07-1.46), and 2.05 (95%CI: 1.64-2.56), respectively. The median PR indicates that when a patient randomly moves to another dental clinic with more regular dental check-ups, this prevalence increased 1.69 times. These results suggest that dental check-up behavior is determined not only by individual factors but also dental-clinic-level factors. Improving the dental-hygienist-related factors is necessary to encourage people to visit dentists for regular check-ups.

A multilevel analysis of the importance of oral health instructions for preventing tooth loss: The 8020 Promotion Foundation Study of Japanese Dental Patients.

BACKGROUND: Many studies have reported risk factors for tooth loss. Oral health instruction is considered effective at improving oral health behavior and oral health. However, few studies have examined the relationship of dental clinic factors, such as the number of dental hygienists and implementation of oral health instructions, with tooth loss. Here, we conducted a multilevel analysis to clarify the dental clinic risk factors associated with tooth loss. METHODS: Baseline surveys were conducted at 1216 dental clinics in 46 prefectures in Japan, and 12,399 dental patients aged 20 years and over underwent oral examinations and completed a questionnaire. The dental clinics also completed a questionnaire at baseline. A 3-year follow-up survey included 2488 patients in 585 dental clinics. Multilevel multivariate logistic regression analysis was used to examine the risk of tooth loss at the patient and clinic levels. RESULTS: Of the patient variables, older age, higher mean probing pocket depth, current or past smoking, and bleeding during tooth brushing were associated with higher risks of tooth loss. Individuals with many teeth who visited dental clinics for maintenance were at significantly lower risk of tooth loss. Of the clinic variables, patients attending dental clinics with four or more dental hygienists had a significantly lower risk of tooth loss (OR 0.68, 95% CI 0.50-0.99). Patients attending dental clinics that provide oral health instructions for 20 min or more had a significantly lower risk of tooth loss (OR 0.69, 95% CI 0.50-0.96). CONCLUSIONS: In addition to individual risk factors for tooth loss, dental clinic factors such as length of oral health instruction and number of dental hygienists are associated with tooth loss. In dental clinics, ensuring sufficient time for dental hygienists to provide oral health instructions can help prevent tooth loss in dental patients.

PRECEDE-PROCEED model based questionnaire and saliva tests for oral health checkup in adult.

Screening is a fundamental strategy for early detection, treatment, and prevention of progression of oral disease and those at high risk for oral disease. While numerous screening tools exist, questionnaires, and saliva tests are often suitable for screening. The questionnaire based on the PRECEDE-PROCEED model was developed, validated, and elucidated on the structural interrelationship between these two methods. In the current investigation, 311 adults had this questionnaire and saliva testing administered simultaneously during an occupational health checkup. The questionnaire was validated by classical test theory, item response theory, and path analysis. Through structural equation modeling, it was found that self-care guidance may be an important role of the family dentist. In addition, self-awareness of oral symptoms was significantly related to saliva test results. However, self-administered questionnaires and saliva tests together may provide more information than either of them alone for the detection, treatment, and prevention of progression of oral disease. Thus, simultaneous application of self-administered questionnaires and saliva tests is recommended during oral health checkups for adults.

Periodontal status and self-reported systemic health of periodontal patients regularly visiting dental clinics in the 8020 Promotion Foundation Study of Japanese Dental Patients.

This nationwide cross-sectional survey investigated the association between periodontal disease and self-reported systemic health in periodontal patients who regularly visited private dental clinics in Japan. Data from 999 patients of 444 dental clinics were analyzed; the patients were aged 40 years or older, regularly visited dentists, and had diagnosed periodontal disease (defined as two or more teeth with a clinical attachment level ≥6 mm). Medical history was collected with a self-reported questionnaire. Number of teeth with a probing pocket depth (PPD) ≥5 mm was used to define periodontal status, and the highest quartile was used as the dependent variable. A Poisson regression model showed that histories of diabetes and hypertension were associated with a larger number of teeth with a PPD ≥5 mm (diabetes: prevalence rate ratio [PRR] 1.36, 95% confidence interval [CI] 1.00-1.85; hypertension: PRR 1.27, 95% CI 1.02-1.58) after adjusting for potential periodontal risk factors. These findings suggest that diabetes and hypertension are associated with worse periodontal disease. Dentists should confirm the diabetes and hypertension status of patients who receive maintenance care, because these conditions could affect periodontal management of patients.

Risk factors for tooth loss in adult Japanese dental patients: 8020 Promotion Foundation Study.

AIM: The assessment of the risk of tooth loss in patients visiting a dental clinic is important for managing their oral health. In the present study, we examined the risk factors for tooth loss among dental patients. METHODS: Data from the 8020 Promotion Foundation Study on the Health Promotion Effects of Dental Care were used in the present study. The study involved 2743 patients who visited a dental clinic in Japan and completed a questionnaire and oral health examination at baseline and at the 2-year follow up. Tooth- and person-level risk factors for tooth loss during 2 years were subjected to a multilevel multivariate logistic regression analysis. RESULTS: In both the person- and tooth-level analyses, age, smoking habit, reason for dental visit, economic status, number of remaining teeth, and periodontal status were significantly associated with tooth loss. In the tooth-level analysis, tooth type, tooth status, and periodontal status were significantly related to tooth loss. Persons who visited a dental clinic for periodic maintenance had a significantly lower risk of tooth loss than those who visited only to receive dental treatment. CONCLUSIONS: Various tooth-level factors and modifiable factors, such as smoking cessation and periodic maintenance, are important for the suppression of tooth loss in dental patients.

Oral health for healthy longevity in an ageing society: maintaining momentum and moving forward.

The ageing of populations worldwide is rapidly accelerating. However, the global burden of oral disease remains a critical and often underestimated problem. As ageing progresses globally, oral health maintenance becomes a matter not only of public health, but also of human rights. Therefore, in low- and middle-income countries, policymakers are seeking to realize universal health coverage even as they struggle with severe resource limitations. To achieve and maintain global oral health, we propose an ongoing global monitoring cycle consisting of the following four steps: needs assessment, implementation of appropriate health care systems and provisions, reducing the global burden of oral disease, and working to achieve a healthy ageing society. Rather than a unidirectional information flow from high income to low- and middle-income countries, the proposed system would establish a multidirectional information-sharing cycle that would benefit all countries. To make this possible, however, we must develop a standardized set of core oral health indicators that all countries use, as well as a global repository for gathering, compiling, and sharing the data. This system would allow each country to move forward at its own pace and in locally-appropriate ways, making it more effective and efficient in the long run than the current pattern of setting unrealistic goals that all countries are expected to achieve by a certain point in time.

Estimated tooth loss based on number of present teeth in Japanese adults using national surveys of dental disease.

Oral health instruction for adults should take into account the potential effect of tooth loss, as this has been suggested to predict further tooth loss. Therefore, the purpose of this study was to determine whether further tooth loss could be predicted from the number of present teeth (PT). We employed the same method as in our previous study, this time using two national surveys of dental disease, which were deemed to represent a generational cohort. Percentiles were estimated using the cumulative frequency distribution of PT from the two surveys. The first was a survey of 704 participants aged 50-59 years conducted in 2005, and the second was a survey of 747 participants aged 56-65 years conducted in 2011. The 1st to 100th percentiles of the number of PT were calculated for both age groups. Using these percentiles and a generational cohort analysis based on the two surveys, the number of teeth lost per year could be calculated. The distribution of number of teeth lost generated a convex curve. Peak tooth loss occurred at around 12-14 PT, with 0.54 teeth being lost per year. The percentage of teeth lost (per number of PT) increased as number of PT decreased. The results confirmed that tooth loss promotes further tooth loss. These data should be made available for use in adult oral health education.

Sex- and age-based differences in single tooth loss in adults.

The aim of this study was to investigate sex- and age-based differences in single tooth loss in adults. The data were obtained from the results of a periodontal disease examination carried out under a health promotion law in a city in Japan in 2005. Baseline data from a total of 3,872 participants aged 40 or 60 years comprising 1,302 men and 2,570 women were available. Only participants with 27 present teeth were eligible for inclusion in the analysis, giving a total of 218 men and 428 women. Third molars were excluded from the study. The bilateral total of each type of tooth was obtained. The mandibular first molar was missing in 26.7% of the men and 36.2% of the women among 40-year-olds and 35.3% of the men and 29.8% of the women among 60-year-olds. The mandibular second molar was missing in 14.7% of the men and 12.5% of the women among 40-year-olds, and 17.6% of the men and 18.4% of the women among 60-year-olds. Significant differences were observed between men and women in the mandibular second premolars and first molars among 40-year-olds. These results suggest that we need to pay more attention to individual teeth which are at particularly high risk for tooth loss, namely the mandibular first and second molars, and especially the mandibular first molars in middle-aged women.

Risk factors affecting third molar autotransplantation during 5 and 10 years.

The aim of this study was to investigate risk factors affecting 5- and 10-year survival in autotransplantation of third molars with complete root formation at dental clinics. Participating dentists were requested to provide information on transplantations performed between 1 January 1990 and 31 December 2009. After data screening and elimination, 183 teeth in 171 men aged 20-72 years (mean, 44.8 years) and 205 teeth in 189 women aged 20-74 years (mean, 42.0 years) were included in the study. A single-factor analysis using the log-rank test revealed that the following factors had a significant influence (p<0.05) on 5-year survival in transplanted teeth in men: recipient site in the maxilla and fewer than 25 present teeth; those for 10-year survival, on the other hand, were recipient site tooth extraction due to periodontal disease, recipient site in the maxilla, fewer than 25 present teeth, and Eichner index Group B1 to C. Cox regression analysis revealed that the odds ratio for 5-year survival for recipient site in the maxilla was 2.873 (95% CI, 1.073-7.695), while that for 10-year survival was 3.713 (95% CI, 1.601-8.609) for recipient site extraction due to periodontal disease, 2.190 (95% CI, 1.021-4.700) for recipient site in the maxilla, and 3.110 (95% CI, 1.470-6.581) for fewer than 25 present teeth. In women, the log-rank test indicated experience of less than 10-year in performing treatment as a significant factor (p <0.05) in 5-year survival. These results suggest that medium-term survival in transplanted teeth is influenced by operational risk factors in women, while long-term survival in transplanted teeth is influenced by individual oral status in men.

Estimated percentile curves of occluding pairs in an adult population.

The purpose of this study was to provide the estimated percentile curves of occlusal pairs (OPs) in adults for use in oral health instruction. Data on number of present teeth (PT) were obtained from the National Report on the Survey of Dental Disease in 2005. Data from 1,535 males and 2,248 females, ranging in age from 18 to 82, were analysed. The mean number of OPs were used from our previous report. In that report we can be estimated OPs from the number of PT. In this study, PT data were replaced by the mean number of OPs. Estimated percentile curves in males, the 10th percentile of OPs was 13.7 at 60 years of age and 12.5 at 70. The 50th percentile of OPs was 12.2 at 50 years of age, 11.2 at 60 and 5.4 at 70. The 90th percentile of OPs was 7.6 at 50 years of age, 2.1 at 60 and 0 at 70. There appeared to be a cut off point after 10 OPs where the 50th to 97th percentile curves of OPs dropped off rapidly. In females, the 10th percentile of OPs was 13.4 at 60 years of age and 12.7 at 70. The 50th percentile of OPs was 11.5 at 50 years of age, 10.2 at 60 and 6.2 at 70. The 90th percentile of OPs was 7.1 at 50 years of age, 2.4 at 60 and 0 at 70. In females again the percentile curves dropped off after 10 OPs. Our results suggest that the loss of OPs may be accelerated when the number of OPs drops below 10. This means that patients need at least 10 OPs in order to maintain a stable oral status. The estimated percentile curves given in this study should be made available for use in adult oral health education.

Survival rate in autotransplanted premolars with complete root formation: a retrospective clinical survey.

The purpose of this study was to analyze the survival rate in autotransplanted premolars with complete root formation in dental clinics. Participating dentists were requested to provide information on transplantations they had undertaken between 1 January 1990 and 31 December 2010. Data on a total of 708 teeth from 637 patients were collected. Data for other tooth types and for teeth with incomplete root formation were eliminated. In this study, data on 40 teeth in 35 patients were analyzed. Participants consisted of 17 men and 18 women ranging from 24 to 79 years in age (mean age, 43.7 years). The cumulative survival rate was 100% at the 5-year mark and 72.7% at 10 years, as calculated by the Kaplan-Meier method. Single-factor analysis revealed that "transplanted to the molar regions" was a significant risk factor (p<0.05) influencing the survival of transplanted teeth. However, a Cox regression analysis showed no significance. The results of this study suggest that, in cases where there is a suitable donor tooth and the oral condition is good, premolar autotransplantation is a viable treatment option, even when there is complete root formation in the donor teeth.

A cross-sectional survey investigating care of the primary dentition by paediatric dental specialists in Japan and the UK.

OBJECTIVE: The aim of this study was to compare treatment decisions in primary dentistry between Japanese and UK-based paediatric dental specialists. METHODS: Four clinical scenarios involving a 6-year-old boy were used to ascertain the clinical opinions of participants. The scenarios presented: (i) a single distal cavity, vital and without pain; (ii) a distal occlusal cavity, vital and without pain; (iii) a large distal occlusal cavity, non-vital and without pain, and (iv) a large distal occlusal cavity, non-vital and painful. Participants were 104 Japanese and 115 UK-based paediatric dental specialists. RESULTS: In the first scenario, some UK specialists showed a preference for vital pulpotomy with a stainless steel crown (10.3% compared with 0.9% in Japan). In the second scenario, Japanese participants were more likely than UK participants to offer traditional restorative care (73.6% vs. 24.1%). In the third scenario, 54.7% of Japanese specialists chose to open the pulp chamber, whereas 51.8% of UK specialists selected non-vital pulpotomy with stainless steel crown. In the final scenario, 74.0% of Japanese specialists chose to open the pulp chamber, whereas 51.8% of UK specialists chose not to offer any treatment other than extraction. CONCLUSIONS: Japanese and UK specialists in paediatric dental care choose different interventions for the same clinical problems.

Dental patient preferences and choice in clinical decision-making.

In economics, the concept of utility refers to the strength of customer preference. In health care assessment, the visual analogue scale (VAS), the standard gamble, and the time trade-off are used to measure health state utilities. These utility measurements play a key role in promoting shared decision-making in dental care. Individual preference, however, is complex and dynamic. The purpose of this study was to investigate the relationship between patient preference and educational intervention in the field of dental health. The data were collected by distributing questionnaires to employees of two companies in Japan. Participants were aged 18-65 years and consisted of 111 males and 93 females (204 in total). One company (Group A) had a dental program of annual check-ups and health education in the workplace, while the other company (Group B) had no such program. Statistical analyses were performed with the t-test and Chi-square test. The questionnaire items were designed to determine: (1) oral health-related quality of life, (2) dental health state utilities (using VAS), and (3) time trade-off for regular dental check-ups. The percentage of respondents in both groups who were satisfied with chewing function, appearance of teeth, and social function ranged from 23.1 to 42.4%. There were no significant differences between groups A and B in the VAS of decayed, filled, and missing teeth. The VAS of gum bleeding was 42.8 in Group A and 51.3 in Group B (p<0.05). The percentage of persons having a regular dental check-up every three months was 34.1 and 31.3% in Groups A and B respectively. These results suggest that low preference results from lack of opportunity or utilization of dental care in the worksite. Ascertaining the factors involved in patient preference may have significant potential benefits in shared decision-making.

Relationship between Eichner Index and number of present teeth.

The aim of this study was to determine the percentage of participants in each of the six Eichner Index groups by number of present teeth (PT). The data were obtained from a periodontal disease examination carried out under a health promotion law in a city located northeast of Tokyo, Japan, in 2005. Data from a total of 1,549 (524 male and 1,025 female) 60-year-old participants were analyzed in this study. Number of occlusal supports was counted by analyzing dental charts. The Eichner Index was used to group the participants into six groups based on distribution of occlusal support teeth. The percentage of patients in Group A with 24 PT was 31.4%; none in Group A had fewer than 19 PT. The percentage in Groups A, B1, and B2 with between 20 and 28 PT was above 50%; the number of participants in these groups with fewer than 20 PT decreased rapidly. Those with fewer than 16 PT were almost found in Groups B3, B4 and C. Only a few patients in Group C had between 10 and 14 PT; those with fewer than 9 PT were only found in Groups B4 or C. Based on these results, the Eichner Index category of a given participant can be estimated from number of PT.

Age- and sex-specific differences in ratio of occluding pairs to number of present teeth.

The aim of this study was to determine age- and sex-specific differences in the ratio of occluding pairs (OPs) to number of present teeth (PT). The data were obtained from a periodontal disease examination carried out under a health promotion law in a city located northeast of Tokyo, Japan, in 2005. Data from a total of 5,131 (1,735 male and 3,396 female) 40-, 50-, and 60-year-old participants were analysed in this study. Occluding pairs were counted by analysing dental charts. Sex-related differences in the ratio of mean PT to OPs were found at 30 PT in 40-year-olds, at 22 PT and 28 PT in 50-year-olds, and at 24 PT and 28 PT in 60-year-olds. Age differences were only found at 28 PT in males. These differences in the ratio of PT to OPs were influenced by the presence of third molars and the type of tooth loss pattern. In some cases the PT-to-OP ratio is influenced by age and sex, but these differences are very small. Age and sex need to be considered when using PT to estimate OPs.