Association of oral fungal profiles with health status and bacterial composition in elderly adults receiving community support and home care service.

Fungi compose a minority but a common component of normal oral microbiota and contribute to oral and systemic health by interacting with bacterial inhabitants. This study investigated the relationship of oral fungal profiles to health status and bacterial profiles of 159 elderly adults receiving community support and home care services. Fungal and bacterial densities and compositions were determined based on the fungal ribosomal internal transcribed spacer region and bacterial 16S rRNA gene amplicon analyses, respectively. The total fungal density of 87 individuals exceeded 5,000 copies, and their microbiota was characterized by significantly less dense bacterial populations and lower relative abundances of oral health-associated taxa, such as Neisseria perflava and Porphyromonas pasteri, compared with those with less than 5,000 copies of fungi. These individuals were significantly older, had fewer teeth, had lower physical function, and comprised more denture users and individuals with cognitive decline. Fungal compositions were classified into three profiles (Candida albicans-dominant, non-albicans Candida-dominant, and non-Candida-dominant), and individuals with a non-albicans Candida-dominant profile exhibited significantly lower physical and cognitive function than those with the Candida albicans-dominant profile. These results demonstrate that a high-density fungal population co-occurs with poor oral and systemic health status of the host and dysbiosis of the bacterial community, and particularly, the overgrowth of non-albicans Candida species may be implicated in worsening systemic conditions. IMPORTANCE: The interaction between fungal and bacterial components involved in the virulence of oral microbiota has received attention. This study demonstrates that an increase in fungal components is associated with a dysbiotic bacterial community and poor health status in elderly adults. Among individuals with a high-density fungal population, particularly, those with a non-albicans Candida-dominant profile had lower physical and cognitive functions than those with a C. albicans-dominant profile. These findings indicate that the evaluation of fungal components, in addition to the bacterial components, is important to understand the involvement of oral microbiota in oral and systemic diseases in elderly adults.

Oral-to-rectum microbial transmission in orthopedic patients without a history of intestinal disorders.

The enrichment of oral taxa in the gut has recently been reported as a notable alteration in the microbial balance in patients with intestinal disorders. However, translocation in populations without such diseases remains controversial. In this study, we examined 49 pairs of tongue and rectal samples collected from orthopedic patients without a history of intestinal disorders to verify the presence of oral taxa in the rectal microbiota. The bacterial composition of each sample was determined using 16S rRNA gene sequencing and amplicon sequence variant (ASV) analysis. Although the bacterial compositions of the tongue and rectal microbiota were distinctly different, tongue ASVs were detected in 67.3% of the participants and accounted for 0.0%-9.37% of the rectal microbiota. Particularly, Streptococcus salivarius, Fusobacterium nucleatum, and Streptococcus parasanguinis were abundant in the rectal microbiota. According to the network analysis, tongue taxa, such as S. salivarius and S. parasanguinis, formed a cohabiting group with Klebsiella pneumoniae and Alistipes finegoldii in the rectal microbiota. The total abundance of tongue ASVs in the rectal microbiota was significantly higher in participants with older age, hypertension, and proton pump inhibitor (PPI) use. Our study presents an extensive translocation of oral taxa to the rectum of a population without intestinal disorders and suggests that aging, hypertension, and PPI use are associated with an increased abundance of oral taxa and potential pathogenic bacteria in the rectal microbiota.

Possible association between oral health status and appetite loss in community-dwelling older adults.

This study aimed to evaluate the association between the oral health status and appetite in community-dwelling older adults. We enrolled 100 people aged ≥65 years who had participated in long-term care prevention projects between December 2018 and January 2019. Appetite was assessed using the Council on Nutrition Appetite Questionnaire score. The oral health status was assessed based on the number of teeth, occlusal condition, swallowing function, tongue coating, and the Oral Health Assessment Tool. A multiple linear regression analysis was performed with appetite as the dependent variable and each variable related to oral health status as an independent variable. The analysis was adjusted for sex, age, activities of daily living, cognitive function, smoking habit, and alcohol consumption. Dental pain was associated with poor appetite in community-dwelling older adults. No other oral health status parameter was associated with appetite. Thus, controlling dental pain is critical to prevent appetite loss while considering other factors.

Establishment of tongue microbiota by 18 months of age and determinants of its microbial profile.

IMPORTANCE: Understanding the development of oral microbiota early in life and the factors that influence it is important for preventing the establishment of dysbiotic oral microbiota later in life. This study demonstrates that the tongue microbiota undergoes early development from 4 to 18 months of age and converges into two types of microbiota showing indications of adult characteristics, with either S. salivarius or Neisseria-dominance. Interestingly, their divergence was strongly determined by their weaning status and the dietary frequencies of sweetened beverages, snacks, and fruits, suggesting that dietary habits during this period might influence the establishment of the oral microbiota. These findings may contribute to the development of novel preventive strategies against oral microbiota-related diseases.

Association of second-hand smoke exposure, quantified by salivary cotinine, with dental caries in Japanese adolescents.

PURPOSE: Second-hand smoke has adverse effects on oral health. This cohort study used a multilevel approach to investigate the association of second-hand smoke exposure, as determined by salivary cotinine level, with dental caries in adolescents. METHODS: Data from 75 adolescents aged 11 or 12 years and 2,061 teeth without dental caries were analyzed in this study. Annual dental examinations to assess dental caries were conducted between 2018 and 2021. Salivary cotinine and Dentocult SM-Strip level were measured at baseline. Information on the smoking habits of parents, snack frequency, regular dental visits, and use of fluoride toothpaste was collected at baseline from parent-reported questionnaires. RESULTS: During the 3-year follow-up, dental caries was noted in 21 adolescents and 43 teeth. Participants exposed to parental smoking had higher salivary cotinine levels than those whose parents did not smoke. The multilevel Cox regression model showed that a high salivary cotinine level was associated with the incidence of dental caries, after adjusting for potential confounding factors (hazard ratio, 3.39; 95% confidence interval 1.08-10.69). CONCLUSION: This study suggests that the risk of dental caries is higher for adolescents who have high salivary cotinine levels attributable to second-hand smoke exposure.

Longitudinal association between periodontal condition and glycaemic status in middle-aged adults: A cross-lagged panel analysis.

AIM: To investigate the existence of a bidirectional temporal relationship between periodontal condition and glycaemic status. MATERIALS AND METHODS: This longitudinal study included 2198 participants with mean age 43.4 ± 7.7 years, who underwent dental examinations in Yokohama, Japan, at two time points, 2003-2004 and 2008-2009, at an interval of 5 years. Periodontal condition was assessed by the mean value of probing pocket depth (PPD) and clinical attachment level (CAL). Glycaemic status was assessed by fasting glucose and glycated haemoglobin (HbA1c). RESULTS: The cross-lagged panel models showed the effect of HbA1c at baseline on mean PPD at follow-up (ß = 0.044, p = .039). There was a marginal effect of fasting glucose on the mean PPD (ß = 0.037, p = .059). It was similar to the effect of fasting glucose or HbAlc on mean CAL. However, in the opposite direction, no effect of mean PPD or CAL at baseline on fasting glucose or HbAlc at follow-up was identified. CONCLUSIONS: This study demonstrated a unidirectional relationship between glycaemic status and periodontal condition. The study population, however, had mostly mild periodontitis. Future studies are needed to investigate the effect of periodontal condition on glycaemic status in patients with severe periodontitis.

Dietary Problems Are Associated with Frailty Status in Older People with Fewer Teeth in Japan.

This study aimed to investigate the association between dietary problems and frailty according to tooth loss in older Japanese people. This cross-sectional study included 160 older people (mean age 82.6 years) from Japan. Frailty status was assessed using the Study of Osteoporotic Fractures (SOF) criteria, which consists of (i) weight loss > 5% in the past year, (ii) inability to perform five chair stands, and (iii) self-perceived reduced energy level. Frailty was defined as the presence of ≥2 items of SOF criteria. Multivariate logistic regression analyses were performed with frailty as the dependent variable and dietary problems as the independent variable, stratified according to having <20 teeth. Low appetite and no enjoyment of eating were associated with frailty after adjusting for covariates in participants with <20 teeth. Dietary problems, including low appetite, eating alone, and negative attitudes toward enjoyment of eating were associated with a self-perceived reduced energy level in participants with <20 teeth. However, this association was not observed in participants with ≥20 teeth. In older people with fewer teeth, dietary problems have been suggested to be associated with frailty. Therefore, it may be necessary to pay attention to dietary problems, especially in older people with tooth loss.

Burden of Oral Diseases and Access to Oral Care in an Ageing Society.

OBJECTIVE: The total years lived with disability among older people, and the concomitant burden of tooth loss in ageing societies have increased. This study is an overview of the burden of oral diseases and access to oral care in an ageing society. METHODS: We selected key issues related to the burden of oral diseases and access to oral care and reviewed the relevant literature. RESULTS: The rising number of older people with teeth increases their oral health care needs. To improve access to oral care, affordability of care is a great concern with respect to universal health coverage. In addition, accessibility is a crucial issue, particularly for vulnerable older adults. To improve oral care access, attempts to integrate oral health care into general care are being made in ageing countries. For this purpose, provision of professional oral care at home through domiciliary visits and provision of daily oral health care by non-dental professional caregivers are important. Oral health care for older people reduces general diseases such as pneumonia and malnutrition, which in turn could reduce further healthcare costs. CONCLUSIONS: To address the growing burden of oral care in ageing societies, special provision of oral health care to vulnerable older people, and integration of oral care with primary care will be required.

High-Level Acquisition of Maternal Oral Bacteria in Formula-Fed Infant Oral Microbiota.

The influx of maternal oral microbes is considered to play an important role in the acquisition and development of infant oral microbiota. In this study, we examined tongue swab samples from 448 mother-infant pairs at 4-month checkups. The bacterial composition of each sample was determined using PacBio single-molecule long-read sequencing of the full-length 16S rRNA gene and the amplicon sequence variant (ASV) approach. Although the infant oral microbiota was distinctly different from the mother oral microbiota, ASVs shared with their biological mother accounted for a median relative abundance of 9.7% (range of 0.0 to 99.3%), which was significantly higher than that of ASVs shared with unrelated mothers. This shared abundance was strongly associated with the feeding method of infants rather than their delivery mode or antibiotic exposure, and formula-fed infants had higher shared abundance than exclusively breastfed infants. Our study presents strain-level evidence for mother-to-infant transmission of oral bacteria and suggests that colonization of maternal oral bacteria is higher in formula-fed infants. IMPORTANCE Acquisition of oral bacteria during infancy can affect the subsequent formation of stable oral microbiota. This study focused on the mother-to-infant transmission of oral bacteria, a major acquisition route of infant oral microbiota, and demonstrated that most infants acquired oral bacteria from their biological mother even at the single-nucleotide level. Our results also indicated that the occupancies of maternal oral bacteria in infant oral microbiota were associated with the feeding methods of infants. These data could increase understanding of the early development of oral microbiota in infants and its potential associations with oral microbiota-related diseases.

Yogurt product intake and reduction of tooth loss risk in a Japanese community.

AIM: To evaluate the longitudinal association between yogurt product intake and oral health in a population-based study. MATERIALS AND METHODS: This study included 1967 Japanese residents aged 40-79 years who underwent dental examinations in 2012. Among them, 1469 participants were followed up in 2017 for the incidence of tooth loss, which was defined as two or more teeth lost over 5 years. The intake of yogurt products, defined as yogurt and lactic acid beverages, was estimated using a semi-quantitative food frequency questionnaire. The composition of the salivary microbiota was evaluated. RESULTS: The Poisson regression model showed that a higher intake of yogurt products was negatively associated with the incidence of tooth loss (p for trend = .020), adjusted for potential confounding factors. Mediation analysis confirmed that periodontal condition partly mediated the effect of yogurt product intake on tooth loss, while dental caries experience did not. Additionally, we confirmed the association of a high intake of yogurt products with a low percentage of the salivary microbiota pattern, which was associated with poor oral health. CONCLUSION: These findings suggest that the intake of yogurt products is associated with a lower risk of tooth loss resulting from periodontal disease, probably via modulation of the oral microbiome composition.

Baseline periodontal status and modifiable risk factors are associated with tooth loss over a 10-year period: Estimates of population attributable risk in a Japanese community.

BACKGROUND: This study aimed to examine whether modifiable risk factors can predict tooth loss over 10 years and estimate population attributable risk (PAR) for a combination of modifiable factors. METHODS: This longitudinal study included 1466 participants who underwent dental examinations in 2007 and 2017 and were aged 40 to 79 years at baseline. Periodontal conditions were assessed using the 2018 periodontal classification. Incident tooth loss was defined as ≥4 teeth lost over a 10-year period. We calculated the partial PAR (pPAR%) for tooth loss to estimate the combined effect of modifiable risk factors. RESULTS: Incidence of tooth loss was 17.5%. Directed acyclic graphs were used to identify risk factors for tooth loss. A logistic regression model showed that baseline periodontitis, dental caries experience, no regular dental visit, periodontal treatment, smoking, and obesity were associated with tooth loss after adjusting for covariates; pPAR% was 55.5% (95% confidence interval: 31.1% to 73.0%) in periodontitis Stage III to IV and 87.6% (50.4% to 97.4%) in the combination of all factors, respectively. The sex-stratified analysis showed that smoking and no regular dental visit in men and obesity in women were identified as potential risk factors for tooth loss. CONCLUSIONS: Modifiable factors accounted for most cases of incident tooth loss. Risk factors for tooth loss might differ by sex, suggesting that the appropriate approach for preventing tooth loss base on sex.

Number of teeth, denture wearing and cognitive function in relation to nutritional status in residents of nursing homes.

BACKGROUND: Although statistical associations between tooth loss and cognitive decline have been reported, there are few previous studies on denture wearing. Additionally, it remains unclear whether nutritional status mediates this association. OBJECTIVE: Our purpose was to test for the hypothesis that the association between the number of teeth and denture wearing with cognitive function is mediated by nutritional status in residents of nursing homes. MATERIALS AND METHODS: We enrolled 162 participants who required long-term care (mean age: 87.7 ± 7.5 years, 26 men and 136 women) and were admitted to eight nursing homes in Fukuoka city, from September 2013 to March 2014. A trained dentist conducted dental and swallowing examinations, and the care-staff assessed nutritional status, comorbid conditions and cognitive function using the Clinical Dementia Rating (CDR). RESULTS: Poisson regression analysis showed that 0-19 teeth without dentures were associated with severe cognitive impairment (CDR 3) (prevalence ratio = 2.00; 95% confidence interval: 1.13-3.55) after adjustment for sex, age, suspected swallowing dysfunction and comorbid conditions. Mediation analysis confirmed that the nutritional status as a mediator of this association (the percentage mediated effect through nutritional status was 23.1%). CONCLUSION: There is an association between dental status and cognitive impairment in elder individuals, and dentures and poor nutrition are involved in this association. However, due to the cross-sectional design of this study, there is a possibility that this association is bidirectional.

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.

10-year trend of tooth loss and associated factors in a Japanese population-based longitudinal study.

OBJECTIVES: We examined the trend in the number of missing teeth in a Japanese community over a 10-year period and the potential associated explanatory factors. DESIGN: Prospective cohort study. SETTING: A population-based study conducted in 2007, 2012 and 2017 in Japan (Hisayama Study). PARTICIPANTS: Residents of a Japanese community aged 40-79 years undergoing dental examination in 2007 (n=2665), 2012 (n=2325) and 2017 (n=2285). OUTCOME MEASURES: The number of missing teeth, periodontal condition, dental caries experience, dental plaque index and oral health behaviours were evaluated each year. The longitudinal analysis of variation in these factors were assessed using mixed models. RESULTS: The age-adjusted and sex-adjusted mean number of missing teeth decreased with time (6.80 in 2007, 6.01 in 2012 and 4.99 in 2017). The mean clinical attachment level (CAL), prevalence of periodontitis and dental plaque index decreased over the study period, while dental caries experience slightly increased. The level of oral health behaviour increased over time. Poisson mixed models showed that changes in mean CAL and dental caries experience were positively associated with the change in the number of missing teeth over time. Linear mixed models showed that changes in dental plaque index and no regular dental visit were positively associated with changes in mean CAL. CONCLUSIONS: These findings suggest that a decreasing trend regarding the number of missing teeth in Japan might be associated with improvements in the periodontal condition due to changes in oral hygiene level and oral health behaviour.

Clinical utility of subgingival plaque-specific bacteria in salivary microbiota for detecting periodontitis.

Saliva contains diverse bacteria shed from various oral sites, including subgingival plaque. It is reasonable to focus on the total occupancy of subgingival plaque-specific bacteria (SUBP bacteria), which live in subgingival environments, in the saliva for detecting periodontitis using salivary testing. This study aimed to validate the clinical utility of SUBP bacteria in the salivary microbiota for the detection of periodontitis. We examined stimulated saliva samples collected from 125 subjects who visited three dental clinics. The relative abundances of previously identified 11 SUBP bacteria were determined using 16S ribosomal RNA gene sequencing and a reference-based approach. The prediction performance was evaluated using a receiver operating characteristic (ROC) curve. The SUBP bacteria accounted for 0-15.4% of the salivary microbiota, and the percentage distinguished periodontitis patients with at least 15 sites with probing depth ≥4 mm with a sensitivity of 0.90 (95% confidence interval [CI], 0.81-0.98) and specificity of 0.70 (95% CI, 0.60-0.80) (area under the ROC curve [AUC], 0.87). Among 2,047 combinations of 11 SUBP bacteria, combinations including Streptococcus constellatus, Porphyromonas gingivalis, and Fusobacterium nucleatum subsp. vincentii demonstrated significantly higher AUC values in their detection. These results suggest that examining SUBP bacteria in saliva may be useful for detecting periodontitis patients in mass screening.

Airflow limitation and tongue microbiota in community-dwelling elderly individuals.

Numerous oral indigenous microorganisms are constantly introduced into the stomach via the laryngopharynx, and a portion of these microorganisms irregularly reaches the lower airways and lungs. This study investigated the association between airflow limitation and the status of tongue microbiota, which is a primary source of ingested oral bacterial populations. The study population consisted of 484 community-dwelling adults aged 70-80 years inhabiting Hisayama town, Japan, who underwent a regular health examination including dental examination and spirometry test in 2016. The bacterial density and composition of their tongue microbiota were determined using a previously used 16S rRNA gene to understand their relationship with oral health conditions. The present cross-sectional study compared the tongue microbiota status between elderly individuals with airflow limitation and those with normal airflow. The total bacterial density of the tongue microbiota of individuals with airflow limitation was significantly higher than that of individuals with normal airflow. Logistic regression analysis demonstrated that a high-biomass tongue microbiota was significantly associated with airflow limitation after adjustment for smoking intensity and other covariates (adjusted OR 1.61, 95% CI 1.01-2.60). Of the predominant commensals, higher amounts of Prevotella melaninogenica and Actinomyces odontolyticus were associated with a higher prevalence of airflow limitation. These results indicate that increased bacterial burden in the tongue microbiota is associated with a higher prevalence of airflow limitation.

Tongue Microbiota Composition and Dental Caries Experience in Primary School Children.

The tongue microbiota of elderly adults is composed of two cohabiting commensal groups and their ratios are related to the number of teeth with dental caries experience. In this study, the variation in the tongue microbiota of primary school children and its relationship with the dental caries experience were investigated. We examined the tongue microbiota of 138 children aged 6 to 7 years and 11 to 12 years (61 and 77 children, respectively) who underwent annual dental examinations. The bacterial composition was determined by sequencing the V1-V2 region of the 16S rRNA gene. Cooccurrence network analysis indicated two groups of cohabiting predominant commensals in the tongue microbiota of children. The microbiota in children without a history of dental caries showed significantly higher relative abundances of one of the cohabiting groups, primarily composed of Neisseria subflava, Porphyromonas pasteri, and Fusobacterium periodonticum, compared to that in children with a history of dental caries, which is consistent with that of elderly adults with fewer teeth with dental caries experience. Linear discriminant analysis effect size (LEfSe) further identified Streptococcus oralis subsp. dentisani, belonging to the aforementioned commensal group, as a discriminant species in children without dental caries experience aged 6 to 7 years and 11 to 12 years. Our results describe the tongue microbiota composition of primary school children without history of dental caries and support the possibility that dental caries experience is accompanied by a shift in the tongue microbiota.IMPORTANCE Dental caries is now considered to be caused by acids produced by the overall dental plaque microbiota rather than by specific pathogens. This study focused on the relationship between dental caries experience and the variations in tongue microbiota, which is adjacent but separate from the dental plaque microbiota. Our results demonstrated that the tongue microbiota of primary school children with no history of dental caries experience was composed of predominant commensals with different relative abundances compared to those present in children with dental caries experience, suggesting that dental caries experience is accompanied by a shift in the tongue microbiota. The maintenance of a healthy tongue microbiota may indirectly contribute to the prevention of dental caries.

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.

Association between periodontitis and fibrotic progression of non-alcoholic fatty liver among Japanese adults.

AIM: Non-alcoholic fatty liver (NAFL) is known to develop into liver fibrosis, which increases the risk of liver cirrhosis and liver cancer. The association between periodontal condition and fibrotic progression of NAFL is unclear. This study aimed to clarify this longitudinal association. MATERIALS AND METHODS: Among 4812 participants aged 35-64 years undergoing annual health check-ups between 2003 and 2004, and follow-up 5 years later, 392 participants were diagnosed with NAFL. After excluding participants with liver fibrosis at baseline, 341 participants were followed up for 5 years. NAFL disease fibrosis score of ≥-1.455 was used to evaluate the probability of the presence of liver fibrosis. RESULTS: During the follow-up period, 10.6% of participants progressed to liver fibrosis. A higher clinical attachment level (CAL) tended to be associated with the incidence of liver fibrosis in the logistic regression analysis (odds ratio [OR] 1.82, 95% confidence interval [CI], 0.94-3.49, p = .074). The stratified analysis by obesity revealed a significant association with higher CAL in obese participants (OR 2.87, 95% CI, 1.23-6.69, p = .015), but not in non-obese participants. CONCLUSION: Higher CAL was associated with an increased probability of liver fibrosis in obese adults with NAFL.

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.