Michiko Furuta

Interrelationship of oral health status, swallowing function, nutritional status, and cognitive ability with activities of daily living in Japanese elderly people receiving home care services due to physical disabilities.

OBJECTIVES Malnutrition and cognitive impairment lead to declines in activities of daily living (ADL). Nutritional status and cognitive ability have been shown to correlate with oral health status and swallowing function. However, the complex relationship among the factors that affect decline in ADL is not understood. We examined direct and indirect relationships among oral health status, swallowing function, nutritional status, cognitive ability, and ADL in Japanese elderly people living at home and receiving home care services because of physical disabilities. METHODS Participants were 286 subjects aged 60 years and older (mean age, 84.5±7.9 years) living at home and receiving home care services. Oral health status (the number of teeth and wearing dentures) was assessed, and swallowing function was examined using cervical auscultation. Additionally, ADL, cognitive ability, and nutritional status were assessed using the Barthel Index, the Clinical Dementia Rating Scale, and the Mini Nutritional Assessment-Short Form, respectively. Path analysis was used to test pathways from these factors to ADL. RESULTS The mean number of teeth present in the participants was 8.6±9.9 (edentates, 40.6%). Dysphagia, malnutrition, and severe cognitive impairment were found in 31.1%, 14.0%, and 21.3% of the participants, respectively. Path analysis indicated that poor oral health status and cognitive impairment had a direct effect on denture wearing, and the consequent dysphagia, in addition to cognitive impairment, was positively associated with malnutrition. Malnutrition as well as dysphagia and cognitive impairment directly limited ADL. CONCLUSIONS A lower number of teeth are positively related to swallowing dysfunction, whereas denture wearing contributes to recovery of swallowing function. Dysphagia, cognitive impairment, and malnutrition directly and indirectly decreased ADL in elderly people living at home and receiving home nursing care. The findings suggest that preventing tooth loss and encouraging denture wearing when teeth are lost may indirectly contribute to maintaining or improving ADL, mediated by recovery of swallowing function and nutritional status.

Sex differences in gingivitis relate to interaction of oral health behaviors in young people

BACKGROUND Although many epidemiologic surveys have shown that gingivitis is more prevalent in males than in females, few studies have clearly explained what causes this difference. The objective of the present study is to explain the sex difference in gingivitis based on the interaction between oral health behaviors and related factors, such as knowledge, attitude, and lifestyle, in young people. METHODS The study was comprised of 838 subjects (440 males and 398 females), aged 18 and 19 years. Gingivitis was assessed by the percentage of bleeding on probing (%BOP). Additional information was collected regarding oral hygiene status, oral health behaviors, and related factors. Structural equation modeling was used to test pathways from these factors to %BOP. Multiple-group modeling was also conducted to test for sex differences. RESULTS Females had greater knowledge, a more positive attitude, a healthier lifestyle, and higher level of oral health behaviors than males. There were significant differences in the paths (i.e., from lifestyle, knowledge, and attitude to %BOP) through oral health behaviors and oral health status. CONCLUSIONS Sex-based differences in gingivitis in young people can be explained by oral health behaviors and hygiene status, which are influenced by lifestyle, knowledge, and attitude. To prevent gingivitis, different approaches to males and females may be useful.

Social capital and self-rated oral health among young people

OBJECTIVES A few studies have revealed the impact of neighborhood social capital on oral health among young people. We sought to examine the associations of social capital in three settings (families, neighborhoods, and schools) with self-rated oral health among a sample of college students in Japan. METHODS Cross-sectional survey of 967 students in Okayama University, aged 18 and 19 years, was carried out. Logistic regression was used to examine the associations of poor self-rated oral health with perceptions of social capital, adjusting for self-perceived household income category and oral health behaviors. RESULTS The prevalence of subjects with poor self-rated oral health was 22%. Adjusted for gender, self-perceived household income category, dental fear, toothbrush frequency, and dental floss use, poor self-rated oral health was significantly associated with lower level of neighborhood trust [odds ratio (OR) 2.22; 95% confidence interval (CI): 1.40-3.54] and lower level of vertical trust in school (OR 1.71; 95% CI: 1.05-2.80). Low informal social control was unexpectedly associated with better oral health (OR 0.54; 95% CI: 0.34-0.85). CONCLUSIONS The association of social capital with self-rated oral health is not uniform. Higher trust is associated with better oral health, whereas higher informal control in the community is associated with worse oral health.

Bacterial diversity in saliva and oral health-related conditions: the Hisayama Study

This population-based study determined the salivary microbiota composition of 2,343 adult residents of Hisayama town, Japan, using 16S rRNA gene next-generation high-throughput sequencing. Of 550 identified species-level operational taxonomic units (OTUs), 72 were common, in ≥75% of all individuals, as well as in ≥75% of the individuals in the lowest quintile of phylogenetic diversity (PD). These “core” OTUs constituted 90.9 ± 6.1% of each microbiome. The relative abundance profiles of 22 of the core OTUs with mean relative abundances ≥1% were stratified into community type I and community type II by partitioning around medoids clustering. Multiple regression analysis revealed that a lower PD was associated with better conditions for oral health, including a lower plaque index, absence of decayed teeth, less gingival bleeding, shallower periodontal pockets and not smoking, and was also associated with tooth loss. By contrast, multiple Poisson regression analysis demonstrated that community type II, as characterized by a higher ratio of the nine dominant core OTUs, including Neisseria flavescens, was implicated in younger age, lower body mass index, fewer teeth with caries experience, and not smoking. Our large-scale data analyses reveal variation in the salivary microbiome among Japanese adults and oral health-related conditions associated with the salivary microbiome.

Nutritional status and dysphagia risk among community-dwelling frail older adults

ObjectivesAlthough the presence of dysphagia is a key determinant of nutritional status among older adults, few studies have focused on the association between malnutrition and dysphagia risk in community-dwelling frail older adults. This study estimated the prevalence of malnutrition and quantified the association between malnutrition and dysphagia risk among community-dwelling older Japanese adults requiring long-term care.DesignCross-sectional study.SettingThis study was conducted with the cooperation of the Japan Dental Association and local dental associations in all 47 prefectures from January to February 2012.ParticipantsIndividuals aged ≥65 years capable of oral nutrient intake who were living at home and receiving home dental care and treatment.MeasurementsIndividual demographic characteristics and factors associated with health loss-related functional decline were obtained through interviews by home-visit dentists and self-administered questionnaires. Nutritional status and dysphagia risk were evaluated using the Mini Nutritional Assessment Short Form and the Dysphagia Risk Assessment for the Community-dwelling Elderly.ResultsAmong 874 respondents (345 men and 529 women), 24.6% were malnourished, 67.4% were at risk of malnutrition, and 8.0% were well nourished. Dysphagia risk was related to an increased likelihood of malnutrition at an old age, even after adjusting for covariates (PR = 1.30, 95% CI = 1.01–1.67).ConclusionMalnutrition is highly prevalent among community-dwelling frail older adults, and dysphagia risk is independently associated with malnutrition. Dysphagia may be an important predictor of malnutrition progression in aged populations.

Oral Health and Swallowing Problems

Oral health impacts systemic health. Therefore, oral care is an important consideration in maintaining quality of life (QOL). Previously, maintenance and improvement of oral hygiene was considered essential for achieving oral health. In addition to oral hygiene, oral care in terms of oral function is now considered to maintain QOL. Ingestion of exogenous nutrients via the oral cavity is fundamental to the function of all higher animals, not only human beings. Chewing and swallowing processes are critical for normal food intake, and adequate saliva supply and oral care to allow proper functioning of these processes are indispensable for maintaining QOL. In this review, we will summarize the relationship between chewing and swallowing and effects of saliva secretion on these functions, and discuss methods to maintain ingestion of exogenous nutrients and prevent swallowing problems, especially in elderly people.

Relationship between periodontitis and hepatic abnormalities in young adults.

Abstract Objective. Obesity has been implicated as a risk factor for periodontitis and non-alcoholic fatty liver disease (NAFLD). In NAFLD, elevated alanine aminotransferase (ALT) is associated with obesity. Although a possible interrelationship between liver function and periodontitis has been reported among the middle-aged population, the correlation in young adults is little known. This study was designed to investigate the relationship between ALT and the presence of periodontitis in university students in Japan. Material and methods. Medical and oral health data were collected in a cross-sectional examination conducted by the Health Service Center of Okayama University. Systemically healthy, non-smoking students aged 18 and 19 years old (n = 2225) were included. The protocol of the United States National Health and Nutrition Examination Survey was applied. Subjects with probing pocket depth ≥ 4 mm were defined as having periodontitis. Logistic regression analysis was used to estimate the association between ALT, body mass index and periodontitis. Results. The number of subjects with periodontitis was 104 (4.7%). In males, having periodontitis was significantly associated with an increased level of ALT (≥ 41 IU/l) in logistic regression analysis (adjusted odds ratio 2.3; 95% confidence interval 1.0–5.2; p < 0.05). However, there was no significant association between periodontitis and ALT in female students. Conclusions. Elevated ALT could be a potential risk indicator for periodontitis among young males. Monitoring hepatic abnormalities to prevent periodontitis must be better understood, even in the young adult population.

Gender differences in the association between metabolic syndrome and periodontal disease: The Hisayama Study

Aims: Periodontal disease and metabolic syndrome (MS) are more prevalent in males than in females. However, whether there is a gender difference in the association between these health conditions has not yet been investigated. This study examined the gender difference in this association, considering the definition of periodontal disease. Materials and Methods: We recruited 1040 males and 1330 females, aged ≥40 years, with at least ten teeth from subjects of the 2007 Hisayama health examination. We performed a logistic regression analysis with various definitions of periodontal disease the dependent variable and MS as the independent variable. Following the analysis, the data were reanalysed with the structural equations model. Results: The logistic regression analysis suggested a stronger association between periodontal disease and MS in females than that in males when periodontal disease was more severely defined. When we constructed the structural equations model in each gender, the model showed a good fit to the data of females, suggesting the association between periodontal disease and MS in females, but not in males. Conclusions: Gender differences seem to exist in the association between periodontal disease and MS; MS might show a stronger association with periodontal disease in females than in males. Furuta M, Shimazaki Y, Takeshita T, Shibata Y, Akifusa S, Eshima N, Kiyohara Y, Ninomiya T, Hirakawa Y, Mukai N, Nagata M, Yamashita Y. Gender differences in the association between metabolic syndrome and periodontal disease: the Hisayama Study. J Clin Periodontol 2013; 40: 743–752. doi: 10.1111/jcpe.12119.

Self-reported aural symptoms, headache and temporomandibular disorders in Japanese young adults

BackgroundTo investigate the associations of aural symptoms, headache and depression with the presence of temporomandibular disorder (TMD) symptoms in a young adult population in Japan.MethodsA personal interview survey was conducted on first-year university students (n = 1,930) regarding symptoms of TMD, aural problems, headache, shoulder pain and depression. Logistic regression was applied to assess the associations of these problems with the presence of TMD symptoms after controlling for age and gender.ResultsAmong the 1,930 students, 543 students exhibited TMD symptoms and were classified into 7 groups: clicking only (Group I, n = 319), pain in the TMJ only (Group II, n = 21), difficulty in mouth opening only (Group III, n = 18), clicking and pain (Group IV, n = 29), clicking and difficulty in mouth opening (Group V, n = 48), difficulty in mouth opening and pain (Group VI, n = 11), and combination of three symptoms (Group VII, n = 97). The control group (n = 1,387) were subjects without any TMD symptoms. After adjusting for age and gender, a strong association was observed between TMD symptoms (Group II and IV) and tinnitus (OR = 12.1 and 13.2, respectively). TMD symptoms (Group I, II and III) were also associated with vertigo and headache. Otalgia and depression were significantly associated with the presence of clicking only.ConclusionsTMD symptoms were significantly correlated to aural symptoms and headache. A functional evaluation of the stomatognathic system should be considered in subjects with unexplained aural symptoms and headache.

Dental plaque development on a hydroxyapatite disk in young adults observed by using a barcoded pyrosequencing approach

Dental plaque is a dynamic microbial biofilm ecosystem that comprises hundreds of species including difficult-to-cultivate bacteria. We observed the assembly of a plaque bacterial community through 16S rRNA gene analysis. Plaque samples that accumulated on a hydroxyapatite disk for 1, 2, 3, 4, 5, and 7 days with saliva on day 0 were collected from 19 young adults using a removable resin splint. Quantitative PCR analysis showed that the total bacterial amount gradually increased and reached a plateau on day 4. Barcoded pyrosequencing analysis revealed that the microbial richness and diversity particularly increased between days 5 and 7. A principal coordinate analysis plot based on unweighted UniFrac showed the community assembly in a time-related manner, which became increasingly similar to the salivary microbiota. Facultative anaerobic bacteria such as Streptococcus, Neisseria, Abiotrophia, Gemella, and Rothia were predominant in the plaque bacterial community in the earlier days, whereas obligate anaerobes, such as Porphyromonas, Fusobacterium, Prevotella, and Capnocytophaga showed increased dominance on later days. UniFrac analysis also demonstrated that dental caries experience had a significant effect on the assembly process. Our results reveal the development pattern of the plaque bacterial community as well as the inter-individual differences associated with dental caries experience.