Occupational Difference in Oral Health Status and Behaviors in Japanese Workers: A Literature Review.

The occupational environment is an important factor for oral health because people spend a long time in the workplace throughout their lives and are affected by work-related stress and occupational health policies. This study aimed to review evidence for the association between occupation and oral health status and behaviors. A literature search of PubMed was conducted from February to May 2022, as well as a manual search analyzing the article origins. Articles were screened and considered eligible if they met the following criteria: (1) published in English; (2) epidemiological studies on humans; and (3) examined the association between occupation and oral health status and behaviors. All 23 articles identified met the eligibility criteria. After full-text assessments, ten articles from Japan were included in this review: four on the association between occupation and dental caries, three on occupation and periodontal disease, two on occupation and tooth loss, and one on occupation and oral health behaviors. An association was apparent between occupation, oral health status and behaviors among Japanese workers. In particular, skilled workers, salespersons, and drivers who work longer hours and often on nightshifts, tended to have poor oral health.

Use of the dental formula from the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

The National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) is a database including health insurance claim and specific health checkup data. Observational studies using real-world big data attract attention because they have certain strengths, including external validity and a large sample size. This review focused on research using the dental formula of the NDB because the number of teeth is an important indicator of oral health. The number of teeth present calculated using the dental formula of periodontitis patients was similar to that from the Survey of Dental Diseases. In addition, the graphs of the presence rates of tooth types by 5-year age groups from the NDB were smoother and had less overlap than those from the Survey of Dental Diseases, and they could detect slight changes in the presence rate that reflected sugar consumption before and after World War II. Using the NDB, a low number of teeth was associated with high medical care expenditures, high risk of aspiration pneumonia, and high risk of Alzheimer's disease. Although there are some restrictions on the use of the NDB, we hope that dental research using the NDB will be further promoted in the future.

Reasons for Tooth Extractions in Japan: The Second Nationwide Survey.

BACKGROUND: More than 10 years have passed since the first nationwide study on the reasons for tooth extraction in Japan. In the present study, we conducted the second nationwide survey to update the previous data. METHODS: This was a descriptive study. A sample population consisting of 5,250 dentists was selected by systematic random sampling using the 2018 membership directory of the Japan Dental Association. The reason for each permanent tooth extraction was documented by each dentist during a period of 1 week from June 4 to June 10, 2018. A questionnaire was provided for documentation. Reasons for tooth extraction were categorised into 6 groups as follows: caries, periodontal disease, fracture, orthodontics, impacted teeth, and others. RESULTS: A total of 2345 identified dentists responded to the questionnaire (recovery rate: 44.8%). Information on 7809 extracted teeth from 6398 patients was obtained. Periodontal disease was the main reason for tooth extraction for both sexes (men: 40.4%, women: 34.9%). Caries accounted for 30.2% of tooth extractions among men and 29.0% among women. Periodontal disease was predominant in the groups older than 55 years of age. Dental fracture accounted for 16.8% of tooth extractions among men and 19.2% among women. CONCLUSIONS: Caries and periodontal disease are still the main reasons for tooth extraction in Japan. Moreover, dentists should note that fractures accounted for approximately one-fifth of permanent tooth extractions after the age of 45 years.

Pneumonia incidence and oral health management by dental hygienists in long-term care facilities: A 1-year prospective multicentre cohort study.

OBJECTIVE: To investigate the association between oral health management (OHM) by dental hygienists and the occurrence of pneumonia, and determine the effectiveness of OHM in pneumonia prevention. BACKGROUND: In long-term care facilities in Japan, the need for professional OHM is increasing with an increase in the number of severely debilitated residents. MATERIALS AND METHODS: A 1-year prospective multicentre cohort study was conducted using data from 504 residents (63 men; mean age: 87.4 ± 7.8 years) in Japanese long-term care facilities. Basic information, medical history, willingness to engage in oral hygiene behaviour, need for OHM and oral conditions were investigated at baseline. In addition, information on the occurrence of pneumonia was collected using a follow-up survey after one year. A Poisson regression analysis with robust standard errors was conducted, with pneumonia as the dependent variable, and factors associated with OHM and pneumonia occurrence as explanatory variables. RESULTS: Overall, 349 (69.2%) residents required OHM by dental hygienists during that year of follow-up. Of those, 238 (68.2%) were provided with OHM, and 18 (7.5%) developed pneumonia. Among the 111 patients (31.8%) who were not provided with OHM, 21 (18.9%) developed pneumonia. The OHM group had lower pneumonia rates than the non-OHM group (prevalence rate ratio: 0.374; 95% CI: 0.210-0.665). CONCLUSION: Oral health management by dental hygienists was associated with a lower incidence of pneumonia among residents of long-term care facilities, underlining the importance of professional OHM for such individuals. It is recommended that OHM be practised routinely in long-term care facilities.

A Validation Study of the National Database of Health Insurance Claims and Specific Health Checkups of Japan Regarding the Annual Number of Tooth Extractions Performed Across the Entire Japanese Population.

This report describes a validation study of data in the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) obtained by nationwide surveys on tooth extractions. The following 3 data sources on tooth extractions in Japan were compared: (1) the Nationwide Survey of the Reasons for Permanent Tooth Extractions in Japan (a previous survey conducted by the present authors); (2) the Statistics on Medical Care Activities in Public Health Insurance; and (3) the 4th NDB Open Data Japan. Source 1 was a nationwide survey conducted in 2018; sources 2 and 3 comprised data that are freely available for use by the public. In Source 1, 2,345 of 5,250 dentists approached responded to the questionnaire (recovery rate: 44.8%). The number of extracted teeth among younger age groups (aged 25-50 years) reported in Source 1 was lower than that in the other two sources. In contrast, the number of extracted teeth among older age groups reported in Source 1 was higher than that reported in the other two sources. However, when stratified by age group, all differences across the 3 sources regarding the mean annual number of tooth extractions were <0.05 teeth/year. The present results suggest that the NDB is a reliable resource for data on tooth extractions performed across the entire Japanese population.

Self-Reported Diabetes Mellitus and Tooth Extraction Due to Periodontal Disease and Dental Caries in the Japanese Population.

Diabetes mellitus is closely related to oral health. We aimed to determine the relationship between diabetes mellitus and tooth extraction due to periodontal disease and dental caries. Japan's second nationwide survey data collected from 4 June to 10 June 2018 was used to identify reasons for tooth extraction among patients aged > 40 years. General dentists collected information on patients who underwent tooth extraction procedures, and the presence of diabetes mellitus was determined through interviews. Multivariable logistic regression was performed to investigate the relationship between diabetes mellitus and the reasons for tooth extraction, including periodontal disease and dental caries. In total, 2345 dentists responded to the survey (response rate 44.8%). We analyzed data on 4625 extracted teeth from 3750 patients (1815 males and 1935 females). Among patients with self-reported diabetes mellitus, 55.4% had extractions due to periodontal disease compared to 46.7% of such extractions among those without self-reported diabetes mellitus. Self-reported diabetes mellitus was significantly associated with tooth extraction due to periodontal disease. No significant differences were observed in dental caries according to self-reported diabetes mellitus status. This study provides further evidence of a significant association between diabetes mellitus and tooth extraction due to periodontal disease.

Association between number of teeth and Alzheimer's disease using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

Associations of numbers of teeth present and of missing teeth with Alzheimer's disease were cross-sectionally analyzed using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Dental care claims data of patients aged 60 years or older diagnosed with periodontitis (n = 4,009,345) or missing teeth (n = 662,182) were used to obtain information about the numbers of teeth present and of missing teeth, respectively, and they were combined with medical care claims data including the diagnosis of Alzheimer's disease. Numbers of teeth present and of missing teeth excluding third molars were calculated using the dental formula in the claims for periodontitis and missing teeth, respectively, and categorized into three groups each. Percentages of subjects treated for Alzheimer's disease with 20-28, 10-19, and 1-9 teeth present were 1.95%, 3.87%, and 6.86%, respectively, in patients diagnosed as having periodontitis, and those treated for Alzheimer's disease with 1-13, 14-27, and 28 missing teeth were 2.67%, 5.51%, and 8.70%, respectively, in patients diagnosed as having missing teeth. Logistic regression models using treatment for Alzheimer's disease as an outcome variable and adjusting for age and sex showed that odds ratios (95% confidence intervals) for patients with 10-19 and 1-9 teeth (reference: 20-28 teeth) were 1.11 (1.10-1.13) and 1.34 (1.32-1.37), respectively, (p<0.001), in patients diagnosed as having periodontitis, and odds ratios (95% confidence intervals) for patients with 14-27 missing teeth and 28 missing teeth (reference: 1-13 missing teeth) were 1.40 (1.36-1.44) and 1.81 (1.74-1.89), respectively, (p<0.001), in patients diagnosed as having missing teeth. In conclusion, the results of the present study using Japanese dental claims data showed that older people visiting dental offices with fewer teeth present and a greater number of missing teeth are more likely to have Alzheimer's disease.

Relationship between decrease of erythrocyte count and progression of periodontal disease in a rural Japanese population.

BACKGROUND: Limited research has been reported on the relationship between periodontal status and erythrocyte parameters. In the present study, longitudinal data from health checkups are used to clarify the relationship between periodontal disease progression and changes in parameters of erythrocytes. METHODS: In this prospective study, a total of 120 subjects (35 men and 85 women; age range: 30 to 63 years) participated in a comprehensive health screening and dental checkup in 2006 and 2007. Medical examinations, including anthropometric and manometric measurements, blood-chemistry tests, and oral examinations, were performed. Subjects with periodontal disease progression (i.e., the progression group) were defined based on the presence of ≥1 tooth demonstrating a longitudinal loss of periodontal attachment ≥3 mm or tooth loss during the study period. The Wilcoxon signed-rank, χ(2), Fisher exact, and Mann-Whitney U tests and stepwise logistic regression analysis were used for statistical analyses. RESULTS: The progression group comprised 30 subjects. A significant difference between the progression and non-progression groups was observed in changes of erythrocyte counts but not those of the body mass index, systolic and diastolic blood pressure, creatinine, fasting blood glucose, hemoglobin, hematocrit, triglycerides, high- and low-density lipoprotein cholesterol, total cholesterol, aspartate and alanine aminotransferase, and γ-glutamyl transpeptidase. Stepwise logistic regression analysis showed that the progression of periodontal disease was associated with a change (year 2007 minus year 2006) of erythrocyte counts (adjusted odds ratio = 0.970; P = 0.009) after adjusting for age at baseline. CONCLUSION: Within the limitations of this study, the progression of periodontal disease is associated with a decrease in erythrocyte counts in a rural Japanese population.

Composition of the bacterial flora in tonsilloliths.

Tonsilloliths are a potential cause of oral malodor. In this study, microbial profiles and composition of tonsilloliths were determined using culture-independent molecular methods and scanning electron microscopy. 16S ribosomal RNA bacterial genes (16S rDNAs) isolated from tonsilloliths of 6 individuals were amplified by PCR and cloned into Escherichia coli. Partial 16S rDNA sequences of approximately 600 bases of cloned inserts were used to determine species identity by comparison with sequences of known species. Characteristics of bacteria on the surface and inside the tonsillolith were analyzed using scanning electron microscopy. Anaerobic bacteria detected in tonsilloliths belonged to the genera Eubacterium, Fusobacterium, Megasphaera, Porphyromonas, Prevotella, Selenomonas and Tannerella, all of which appear to be associated with production of volatile sulfur compounds. Electron microscopy revealed cocci and rods on the surface and rods predominating inside the tonsilloliths. These results support the tonsillolith as an origin of oral malodor.

Radiographic evaluation of periapical status and prevalence of endodontic treatment in an adult Japanese population.

OBJECTIVES: To determine the prevalence of periapical radiolucencies and endodontic treatment in an adult Japanese population. STUDY DESIGN: Periapical status and length of root fillings of 672 adult patients attending Okayama University Hospital of Dentistry were evaluated using full mouth intraoral radiographs. RESULTS: Overall, 87% of the subjects had root-filled teeth, and 70% exhibited an apical radiolucency. Of the 16,232 teeth examined, 21% had been root-filled, and, of these, 40% exhibited an apical radiolucency. Root-filled teeth that were overfilled or that were mandibular incisors had the highest prevalence of apical radiolucencies. CONCLUSIONS: The prevalence of root-filled teeth appears higher in this Japanese population than in Europe or America; however, the ratio of teeth with an apical radiolucency to root-filled teeth was within the range of that reported for other countries. Overfilled teeth and mandibular incisors are most likely to exhibit apical radiolucencies.