Association between total functional tooth unit score and hemoglobin A1c levels in Japanese community-dwelling individuals: the Nagasaki Islands study.

BACKGROUND: It is widely recognized that periodontal disease is associated with diabetes mellitus. Periodontal disease is accompanied by inflammation of the periodontal tissue, impaired masticatory function, and the presence of periodontopathic bacteria, all of which may affect glycemic control. However, the exact relationship between these factors and glycemic control has not yet been established. In this study, we aimed to investigate the relationship between periodontal disease-related factors and glycemic control in Japanese community-dwelling individuals. METHODS: We conducted a cross-sectional study involving 671 participants aged 29-92 (65.3 ± 12.1) years, using data from the Nagasaki Islands Study. Participants underwent routine medical examinations, including body mass index (BMI) and hemoglobin A1c (HbA1c) levels. Information on the participants' demographics (age and sex) and whether they were on diabetes medications, had an exercise habit, consumed alcohol, engaged in late-night eating, had regular dental checkups, and smoked was obtained using a self-administered questionnaire. Dental examinations were performed to examine dentition status, probing pocket depth, clinical attachment level (CAL), and bleeding on probing. Functional tooth units (FTUs), defined as pairs of occluding posterior teeth, were used as an indicator of occlusal support area. Saliva samples were collected and levels of two species of periodontopathic bacteria (Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans) were determined using real-time polymerase chain reaction. We analyzed the association between HbA1c levels and variables related to periodontal status, masticatory function, and salivary levels of periodontopathic bacteria. RESULTS: Bivariate analysis showed that HbA1c levels were significantly associated with age, sex, exercise habit, BMI, diabetes medications, CAL, salivary P. gingivalis level, number of teeth, and three FTU subcategories. In the multiple regression analysis, age, BMI, diabetes medications, and total FTU score (i.e., including natural teeth, implant-supported artificial teeth, fixed prostheses, and removable dentures) remained associated with HbA1c levels (B = 0.23, 0.14, 0.52, and - 0.12; p < 0.001, p < 0.001, p < 0.001, and p = 0.008, respectively). CONCLUSIONS: In this community-based cross-sectional study, total FTU was significantly associated with HbA1c levels, independent of other risk factors. This suggests that reconstructed occlusal support areas, including dentures, are associated with glycemic control in the older population.

Profile of Nagasaki Islands Study (NaIS): A Population-Based Prospective Cohort Study on Multi-disease.

In an aging society, it is important to visualize the conditions of people living with diseases or disabilities, such as frailty and sarcopenia, and determine the environmental and genetic factors underlying such conditions. Atherosclerosis and arterial stiffness are key conditions between these factors and noncommunicable diseases. In 2014, we launched a population-based prospective open-cohort study, the Nagasaki Islands Study (NaIS), which was conducted in Goto City, located in the remote islands of Nagasaki Prefecture, Japan, mostly involving middle-aged and older residents. We conducted our own health checkups along with the annual standardized checkups organized by the municipality; recruited study participants; and started to follow-up with them for vital status (death), migration, and occurrence of diseases such as myocardial infarction, stroke, fracture, and human T-cell leukemia virus type 1 (HTLV-1) -associated uveitis. Our checkups were conducted as baseline surveys in different areas of Goto City during the fiscal years 2014-2016, secondary surveys during 2017-2019, and tertiary surveys since 2021, consisting of medical interviews, physical examinations, blood and urine tests, body composition measurements, osteoporosis screening, arterial stiffness measurements, carotid ultrasonography, and dental examination. A total of 4,957 residents participated in either the baseline or secondary surveys and were followed-up; and 3,594 and 3,364 residents (aged 27-96 and 28-98 years) participated in the baseline and secondary surveys, respectively. In conclusion, the NaIS has been undertaken to reveal the influence of aging and risk factors of noncommunicable diseases and disabilities, with an aim to contribute towards better healthcare in the future.

Association between periodontitis and chronic kidney disease by functional atherosclerosis status among older Japanese individuals: A cross-sectional study.

AIM: This study aimed to clarify the influence of functional atherosclerosis on the association between periodontitis and chronic kidney disease (CKD). MATERIALS AND METHODS: A cross-sectional study of 998 older Japanese individuals aged 60-99 years who participated in an oral health check-up was conducted. Early and advanced periodontitis were defined as periodontal pocket depth of 4.0-5.9 mm and ≥6.0 mm, respectively. Functional atherosclerosis was defined as cardio-ankle vascular index ≥9.0. RESULTS: Of the 998 study participants, 238 (23.8%) had CKD. No significant associations between periodontitis and CKD were observed in participants without functional atherosclerosis. After adjusting for known cardiovascular risk factors, the odds ratio (OR) (95% confidence interval [CI]) was 1.31 (0.81-2.11) for early periodontitis and 0.74 (0.41-1.34) for advanced periodontitis. Significant positive associations were observed for participants with functional atherosclerosis; the adjusted ORs (95% CIs) were 1.76 (1.04-3.01) for early periodontitis and 1.95 (1.05-3.63) for advanced periodontitis. CONCLUSIONS: A significant positive association between periodontitis and CKD was established for older participants with functional atherosclerosis. No significant associations were observed for those without functional atherosclerosis. These results can help clarify the influence of periodontitis on systemic circulation.

Tooth Loss and Carotid Intima-Media Thickness in Relation to Functional Atherosclerosis: A Cross-Sectional Study.

Structural arterial stiffness can be evaluated with carotid intima-media thickness (CIMT). Functional arterial stiffness can be evaluated with cardio-ankle vascular index (CAVI). A positive association between CIMT and tooth loss has been reported, but no studies have evaluated the association between CIMT and tooth loss in relation to functional arterial stiffness (functional atherosclerosis). A cross-sectional study of 1235 Japanese individuals aged 40-89 years was conducted. Tooth loss was defined as being in the lowest tertile for the number of remaining teeth (≤20 in men and ≤19 in women). Functional atherosclerosis was defined as CAVI ≥ 9.0. Independent of known confounding factors, CIMT was positively associated with tooth loss only in participants without functional atherosclerosis. Adjusted odds ratios for tooth loss and a 1 standard deviation increment in CIMT were 1.27 (1.04-1.55) for participants without functional atherosclerosis and 0.99 (0.77-1.26) for participants with functional atherosclerosis. CIMT and functional atherosclerosis had a significant effect on tooth loss; the fully adjusted p-value for the interaction on tooth loss was 0.019. Independent of known confounding factors, CIMT is positively associated with tooth loss only in participants without functional atherosclerosis. This finding helps clarify the influence of the progression of arterial stiffness on tooth loss because the progression of structural atherosclerosis might have a beneficial influence on the maintenance of the microcirculation.

Association of neutrophil-to-lymphocyte ratio with severe radiation-induced mucositis in pharyngeal or laryngeal cancer patients: a retrospective study.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) is a marker of systemic inflammation that informs clinical decisions regarding recurrence and overall survival in most epithelial cancers. Radiotherapy for head and neck cancer leads to mucositis in almost all patients and severe radiation-mucositis affects their quality of life (QOL). However, little is known about the NLR for severe mucositis. Therefore, this study aimed to show the association between the NLR and severe radiation-induced mucositis in hypopharyngeal or laryngeal cancer patients. METHODS: In this retrospective study, we determined the incidence of grade 3 mucositis in 99 patients who were receiving definitive radiotherapy or chemoradiotherapy (CRT) for hypopharyngeal or laryngeal cancer. We performed univariate and multivariate logistic regression analyses to investigate the characteristics of grade 3 mucositis. Kaplan-Meier curves and log-rank tests were used to evaluate the occurrence of grade 3 mucositis between two groups with high (NLR > 5) or low (NLR < 5) systemic inflammation. RESULTS: The incidence of grade 3 mucositis was 39%. Univariate logistic regression analysis showed that the NLR (Odd ratio [OR] = 1.09; 95% confidence interval [CI] = 1.02-1.16; p = 0.016) and smoking (OR = 1.02; 95% CI = 1.00-1.03; p = 0.048) were significantly associated with grade 3 mucositis. Multivariate logistic regression analysis showed that the NLR was independently associated with grade 3 mucositis (OR = 1.09; 95% CI = 1.01-1.17; p = 0.021). Kaplan-Meier curves also showed that patients with higher NLR (NLR > 5) prior to radiotherapy developed grade 3 mucositis more frequently than those with lower NLR during radiotherapy (p = 0.045). CONCLUSION: This study suggests that a higher NLR is a risk factor and predictor of severe radiation-induced mucositis in hypopharyngeal or laryngeal cancer patients.

Oral health-related quality of life is associated with physical frailty: A cross-sectional study of Japanese community-dwelling older adults.

BACKGROUND: Physical frailty is related to adverse outcomes, and poor oral health has been linked to malnourishment. Subjective measures of oral health-related quality of life (OHRQoL) have been used as indicators of the oral health problems of older adults, and they have been associated with malnourishment. This study aimed to assess OHRQoL's association with physical frailty. METHODS: Cross-sectional study was conducted using data from the Nagasaki Islands Study that enrolled participants aged ≥60 years at Japanese national medical check-ups from 2014 to 2019. Physical frailty phenotype criteria were determined using the modified Fried frailty phenotype model. OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI). Dentists conducted clinical dental examinations. Simple correlation and linear regression analyses were performed to investigate the associations of number of physical frailty phenotype criteria with GOHAI and other oral health indicators. RESULTS: Among 1341 participants with a mean age of 72 years, GOHAI score was significantly associated with number of physical frailty phenotype criteria (B = -0.01, 95% confidence interval: -0.02 to -0.01, p < 0.001). The association remained significant after adjustment for age, sex, body mass index, history of hypertension, history of diabetes mellitus, smoking status, Kessler-6 score, and number of remaining teeth. CONCLUSIONS: Oral health-related quality of life was associated with physical frailty in Japanese community-dwelling older adults.

The Relationship between Dental Findings and Tongue Pressure: A Survey of 745 Community-Dwelling Adults and Elderly Persons in Japan.

INTRODUCTION: Reduced tongue pressure is one of the causes of dysphagia. The purpose of this study was to investigate the relationship between dental findings and tongue pressure, and whether prosthetic treatment prevents reduced tongue pressure. METHODS: This was a cross-sectional study. Participants were 745 community-dwelling adults and elderly persons in the Goto Islands in Nagasaki, who underwent a health checkup for residents in 2015 and 2016. Data were collected on gender; age; grip strength; hemoglobin; Creatinine (Cr); glycated hemoglobin (HbA1c); history of stroke; smoking, drinking, exercise, and walking habits; number of teeth; wearing of removable dentures; functional units of natural teeth (n-FTUs), fixed prostheses (nif-FTUs), and removable dentures (t-FTUs); and tongue pressure. The associations between each variable and tongue pressure were examined using multiple regression analysis. Next, those with 3 or fewer n-FTUs were selected, and differences in tongue pressure were compared between those with 3 or fewer nif-FTUs and those with 4 or more nif-FTUs, using a propensity score matching method. RESULTS: Male gender, weak grip strength, low HbA1c, no drinking, and a low number of teeth were independent factors significantly associated with lower tongue pressure. Among participants with 3 or fewer n-FTUs, the 43 with 4 or more nif-FTUs showed significantly higher tongue pressure than the 43 with 3 or fewer nif-FTUs after propensity score matching, although the number of t-FTUs was not associated with tongue pressure. DISCUSSION/CONCLUSION: Tooth loss was significantly associated with lower tongue pressure. It was suggested that fixed prosthesis treatment might prevent the reduction of tongue pressure, but removable dentures did not have such an effect.

Association between high psychological distress and poor oral health-related quality of life (OHQoL) in Japanese community-dwelling people: the Nagasaki Islands Study.

BACKGROUND: We investigated the association between psychological distress and oral health status/oral health-related quality of life (OHQoL) in Japanese community-dwelling people. METHODS: We conducted a cross-sectional study using data from the Nagasaki Islands Study. A total of 1183 (455 men and 728 women) has been analyzed in this study. Psychological distress was measured using the Kessler Psychological Distress Scale (K6). Oral health status was measured by dental examination. The OHQoL was measured using the General Oral Health Assessment Index (GOHAI). We defined the total score of ≥5 points on the K6 as high psychological distress (high-K6 group). RESULTS: The multiple linear regression analysis to identify the GOHAI showed that gender, K6, the total number of teeth, the number of dental caries, and visiting a dental clinic within the past 6 months significantly associated with the GOHAI. Among all of these variables, high-K6 (≥ 5) was a substantial contributing factor of the GOHAI (ß = - 0.23, 95% Cl - 2.31 to -1.41, p < 0.0001). CONCLUSIONS: It is likely that the individual with high psychological distress was strongly related to poor OHQoL even in the general population.

Evaluation of endobronchial volatile sulfur compounds for rapid diagnosis of lung abscesses caused by obligate anaerobes using Oral Chroma™: A pilot study.

Endobronchial volatile sulfur compounds in patients with lung abscess or lung cancer were measured using the Oral Chroma™ gas chromatograph. High levels of hydrogen sulfide and methyl mercaptan were observed in some patients with lung abscess but not in patients with lung cancer. Measuring endobronchial volatile sulfur compounds could be useful for the rapid diagnosis of lung abscess caused by obligate anaerobes.

Association of low fetuin-A levels with periodontitis in community-dwelling adults.

Fetuin-A is a liver-secreted glycoprotein isolated from fetal bovine serum. Recent reports of its several pathological functions suggest an association between fetuin-A and systemic diseases. This study therefore examined the correlation between serum fetuin-A level and periodontal status. Data from 356 middle-aged and elderly adults who underwent health examinations in Goto, Japan, during the period from 2008 through 2010 were analyzed. Systemic and periodontal measurements were recorded, and serum fetuin-A level was determined by using an enzyme-linked immunosorbent assay. Fetuin-A levels for participants with moderate to severe periodontitis were significantly lower than those for participants with no or mild periodontitis. Additionally, fetuin-A level negatively correlated with periodontal clinical attachment loss. Moderate to severe periodontitis was significantly correlated with low serum fetuin-A levels (odds ratio, 1.69; 95% confidence interval, 1.01-2.69) in logistic regression analysis. Low serum fetuin-A level was correlated with worse periodontal status and could thus potentially serve as a marker of periodontitis.

Association between human T cell leukemia virus type-1 (HTLV-1) infection and advanced periodontitis in relation to atherosclerosis among elderly Japanese: a cross-sectional study.

BACKGROUND: Human T cell leukemia virus type-1 (HTLV-1) stimulates inflammation activity. Our previous study revealed a positive association between asymptomatic HTLV-1 infection and advanced periodontitis among elderly Japanese individuals with low levels of hematopoietic activity (reflected by reticulocyte levels). Since low hematopoietic activity has been correlated with low-grade inflammation and low-grade inflammation is associated with atherosclerosis, the status of atherosclerosis could, in turn, determine the nature of this association. METHODS: To this end, a cross-sectional study of 907 elderly Japanese individuals (aged 60-99 years), who had participated in dental health check-up during the period 2016-2018, was conducted. Advanced periodontitis was defined as periodontal pocket ≥ 6.0 mm. RESULTS: Among the study population, 295 (32.5%) were found to have atherosclerosis defined as a carotid intima-media thickness (CIMT) of ≥ 1.1 mm. HTLV-1 infection was positively associated with advanced periodontitis in participants with atherosclerosis, but no significant associations were observed among the participants without atherosclerosis. The known risk factors' (including reticulocyte and CIMT) adjusted odds ratio (OR) and 95% confidence interval (CI) of advanced periodontitis were OR 2.01 and 95% CI 1.06-3.81 for participants with atherosclerosis and OR 0.61 and 95% CI 0.34-1.12 for participants without atherosclerosis. CONCLUSION: This study found a significant association between HTLV-1 infection and advanced periodontitis among elderly Japanese with atherosclerosis. However, this association is absent in individuals without atherosclerosis, suggesting that atherosclerosis might act as a determinant in the association between HTLV-1 infection and advanced periodontitis among elderly Japanese.

Association between human T cell leukemia virus 1 (HTLV-1) infection and advanced periodontitis in relation to hematopoietic activity among elderly participants: a cross-sectional study.

BACKGROUND: We reported that human T cell leukemia virus 1 (HTLV-1) infection is positively associated with atherosclerosis. Recent evidence has revealed a close association of periodontitis with atherosclerosis, endothelial dysfunction, and disruption of the microcirculation. However, the association between HTLV-1 and advanced periodontitis has not been investigated to date. Since hematopoietic activity is closely linked to endothelial maintenance activity and is known to decline with age, we hypothesized that the state of hematopoietic activity influenced the association between HTLV-1 and advanced periodontitis in elderly participants. METHODS: A cross-sectional study was performed including 822 elderly participants aged 60-99 years who participated in a dental health check-up. Advanced periodontitis was defined as a periodontal pocket ≥ 6.0 mm. Participants were classified as having low or high hematopoietic activity according to the median values of reticulocytes. RESULTS: HTLV-1 infection was positively related to advanced periodontitis among participants with lower hematopoietic activity (lower reticulocyte count), but not among participants with higher hematopoietic activity (higher reticulocyte count). The adjusted odds ratio (95% confidence interval) considering potential confounding factors was 1.92 (1.05-3.49) for participants with a lower reticulocyte count and 0.69 (0.35-1.36) for participants with a higher reticulocyte count. CONCLUSIONS: Among elderly participants, the association between HTLV-1 infection and advanced periodontitis is influenced by hematopoietic activity. Since hematopoietic activity is associated with endothelial maintenance, these findings provide an efficient tool for clarifying the underlying mechanism of the progression of periodontitis among elderly participants.

Association between number of pairs of opposing posterior teeth, metabolic syndrome, and obesity.

We investigated the relationship between the number of pairs of posterior teeth and metabolic syndrome (MetS), abdominal obesity (AO), and obesity, among Japanese adults. In 2005, 2,807 Japanese adults aged 25-74 years participated in the Survey of Dental Diseases and the National Health and Nutrition Survey. Based on the survey data, BMI, AO (JAS) determined by the Japan Atherosclerosis Society, AO (IDF) by the International Diabetes Federation, and MetS were assessed. Total functional tooth units (t-FTUs) were scored with pairs of opposing posterior teeth, including artificial teeth. Subjects were divided into three categories of chewing ability based on the score of t-FTUs: Poor (if score ≤ 9), Good (if score = 10-11), and Complete (if score = 12). The relationships between chewing ability and BMI ≥ 25, BMI ≥ 30, AO (JAS), AO (IDF), and MetS were tested using univariate and multivariate logistic regression analysis. The chewing ability was significantly associated with MetS, AO, and obesity in the univariate and multivariate logistic regression analysis. Adjusted OR of "Poor" compared to "Complete" were 1.51 (95% confidence interval (CI), 1.24-1.84) for BMI ≥ 25, 2.10 (95% CI 1.40-3.14) for BMI ≥ 30, 1.31 (95% CI 1.07-1.61) for AO (JAS), 1.40 (95% CI 1.15-1.70) for AO (IDF), and 1.34 (95% CI 1.04-1.72) for MetS. All were statistically significant. Preventing tooth loss and maintaining pairs of good chewing ability may be important factors in preventing MetS, AO, and obesity.

Associations among Obesity, Eating Speed, and Oral Health.

OBJECTIVE: This study was conducted to understand how eating speed and oral health condition are associated with obesity in Japanese working men. METHODS: We studied a total of 863 men attending an annual medical checkup of the Japanese Maritime Self Defense Force in Sasebo City, Japan. Participants answered a questionnaire about their eating speed, and we examined their anthropometric status in terms of BMI, waist circumference, and oral health condition, especially periodontal disease and number of functional teeth. Multivariate logistic regression analyses adjusting for potential confounding variables were performed. RESULTS: The multivariate-adjusted odds ratio for waist circumference greater than 90 cm of the 'very fast' group compared to the 'slow, very slow' group was 5.22 (95% confidence interval 1.81-15.06) after adjusting for potential confounding factors. Individuals were more likely to have waist circumference greater than 90 cm if they had a larger 'number of missing functional teeth' (odds ratio 1.14; 95% confidence interval 1.01-1.28) and severe periodontal disease (odds ratio 2.74; 95% confidence interval, 1.46-5.13). CONCLUSION: Eating speed, the number of missing functional teeth, and severe periodontal disease are associated independently with larger waist circumference.

Relationship among salivary antioxidant activity, cytokines, and periodontitis: the Nagasaki Island study.

AIM: Antioxidant activities and cytokine levels in human body fluids are considered to be strongly associated with periodontitis. The aim of this study was to elucidate the relationship between salivary antioxidant activities against superoxide or hydroxyl radical, cytokines, and periodontal conditions through a community-based cross-sectional study conducted in Goto city, Japan. MATERIALS AND METHODS: Saliva samples were analysed for superoxide or hydroxyl radical scavenging activities and cytokine levels from 160 participants. We demonstrated that saliva contained superoxide and hydroxyl radical scavenging activities by using electron spin resonance with a spin-trapping agent. The concentrations of eight cytokines were measured using multiplex bead assays. RESULTS: There were significant differences in salivary superoxide or hydroxyl radical scavenging activity, and the levels of Interleukin-1ß, Interleukin-6, and Interleukin-8 between periodontitis classifications. Multivariate stepwise logistic regression model showed that salivary superoxide and hydroxyl radical scavenging activities were significantly associated with the classification of periodontitis. In addition, salivary superoxide scavenging activity was found to have significant association with all periodontal parameters using multiple linear regression analysis. CONCLUSIONS: These findings suggest that the evaluation of salivary antioxidant activities, as assessed by electron spin resonance, are associated with periodontitis and various clinical variables in community-dwelling participants (ClinicalTrials.gov number NCT01742728).

Association of periodontitis with carotid artery intima-media thickness and arterial stiffness in community-dwelling people in Japan: the Nagasaki Islands study.

OBJECTIVE: Recent studies have suggested an association between periodontitis and atherosclerosis; however, the relationship between periodontal status and arterial alterations should be clarified. The purpose of this study was to examine associations between periodontal status and carotid intima-media thickness (cIMT) and arterial stiffness using the cardio-ankle vascular index (CAVI) in community dwellers. METHODS: A community-based cross-sectional study of 1053 subjects ≥40 years with 10 teeth or more was conducted in Goto, Japan from 2008 to 2010. RESULTS: In a multiple linear regression analysis adjusted for age, sex, number of present teeth, and other confounders, each 1-mm increase in mean periodontal pocket depth corresponded to a 0.02-mm increase in maximal cIMT (ß = 0.018; P = 0.049) and also to a 0.1 increase in mean CAVI (ß = 0.133; P = 0.040). In addition, each 1-mm increase in the mean periodontal attachment loss corresponded to a 0.01-mm increase in maximal cIMT (ß = 0.013; P = 0.040). A multiple logistic regression analysis revealed that each 1-mm increase in mean periodontal pocket depth was associated with an increased risk of a maximal cIMT >1 mm (adjusted odds ratio [OR], 1.430; 95% confidence interval [CI], 1.067-1.918; P = 0.017) and mean CAVI of ≥8 (OR, 1.323; 95% CI, 1.003-1.743; P = 0.047). Furthermore, each 1-mm increase in mean periodontal attachment loss was associated with an increased risk of a maximal cIMT >1 mm (OR, 1.251; 95% CI, 1.032-1.516; P = 0.022). CONCLUSION: A linear, dose-dependent relationship was found between periodontal pocket depth, cIMT, and arterial stiffness.

Cessation age of breast-feeding and pacifier use is associated with persistent finger-sucking.

PURPOSE: Although some studies have reported that breast-feeding and pacifier use influence finger-sucking, few have demonstrated whether the age at cessation of breast-feeding or pacifier use and persistent finger-sucking are related. Therefore, the purpose of this study was to examine whether the age at cessation of breast-feeding and pacifier use influenced persistent finger-sucking. METHODS: A cross-sectional study of 555 36- to 47-month-olds was conducted in Nagasaki, Japan, using a questionnaire. Using the optimal cutoff point in a receiver-operating characteristic curve, the age was estimated at which cessation of pacifier use and breast-feeding had the most significant effect on persistent finger-sucking, and the estimated ages were assessed by multiple logistic regression analysis, incorporating all the questions in the questionnaire as independent variables. RESULTS: The odds ratios for persistent finger-sucking when breast-feeding was stopped at an age younger than 12 months old or when pacifier use was stopped at an age younger than 14 months old were 3.77 (95 percent confidence interval (CI)=1.97-7.22) and 8.62 (95 percent CI=2.56-29.04), respectively. CONCLUSIONS: Cessation of breast-feeding before 12 months old or pacifier use before 14 months old was associated with persistent finger-sucking.

Monitoring time-related trends in dental caries in permanent teeth in Japanese national surveys.

OBJECTIVES: According to dental examinations of 3- and 12-year-old children conducted throughout Japan, the prevalence of dental caries in children is decreasing. However, little is known about changes in the prevalence of dental caries in adults. This study analysed past and present prevalences of dental caries in permanent teeth and predicted future trends in dental caries in adults. METHODS: Data were sourced from nine national dental surveys conducted in Japan at 6-year intervals from 1957 to 2005. Data from oral examinations were recorded as indices of decayed, missing and filled teeth. RESULTS: The mean number of filled teeth increased markedly, whereas mean numbers of decayed teeth and missing teeth decreased substantially in people aged ≥ 40 years. By contrast, the mean number of filled teeth first increased and then decreased in groups aged 5-39 years. CONCLUSIONS: Among Japanese respondents sampled in a series of cross-sectional studies between 1957 and 2005, the incidence of dental caries in young adults decreased, suggesting a decrease in prevalences of dental caries in future generations. However, this tendency was not observed in respondents aged ≥ 40 years. The results suggest adults will experience less dental caries in the near future.

Early childhood caries.

Dental caries is one of the most common childhood diseases, and people continue to be susceptible to it throughout their lives. Although dental caries can be arrested and potentially even reversed in its early stages, it is often not self-limiting and progresses without proper care until the tooth is destroyed. Early childhood caries (ECC) is often complicated by inappropriate feeding practices and heavy infection with mutans streptococci. Such children should be targeted with a professional preventive program that includes oral hygiene instructions for mothers or caregivers, along with fluoride and diet counseling. However, these strategies alone are not sufficient to prevent dental caries in high-risk children; prevention of ECC also requires addressing the socioeconomic factors that face many families in which ECC is endemic. The aim of this paper is to systematically review information about ECC and to describe why many children are suffering from dental caries.

Relationship between periodontal status and HbA1c in nondiabetics.

OBJECTIVES: Many studies have reported an association between diabetes and periodontitis. We analyzed the periodontal status and glycosylated hemoglobin (HbA1c) level in nondiabetic subjects to investigate the relationship between periodontitis and glucose control in nondiabetics. METHODS: Periodontal status, HbA1c, serum cholesterol, triglyceride, body mass index (BMI), and demographic variables were assessed in 141 Japanese adults. The difference in the HbA1c level was evaluated among subjects according to periodontal status. RESULTS: After adjusting for age, gender, BMI, and smoking, alcohol, and exercise habits as covariates, the mean HbA1c was significantly elevated with periodontal deterioration (P = 0.023). CONCLUSIONS: There was a significant relationship between periodontal status and HbA1c levels in nondiabetics.