The IL18 Promoter Polymorphism, rs1946518, Is Associated with the Risk of Periodontitis in Japanese Women: The Kyushu Okinawa Maternal and Child Health Study.

Interleukin-18 (IL-18) is a proinflammatory cytokine that plays an important role in periodontitis and its polymorphisms might modulate the individual susceptibility to periodontitis. Only a limited number of studies on the association between IL18 single-nucleotide polymorphisms (SNPs) and the risk of periodontitis have been realized, however. The aim of this case-control study among young post-partum Japanese women (18 to 45 years) was to determine the impact of SNPs, rs1946518 (-607 C/A) and rs187238 (-137G/C), on periodontitis. The two SNPs may be located within a transcription factor-binding element, thereby influencing transcription from the IL18 promoter. Subjects were 131 cases who had at least one tooth with a probing pocket depth of ≥ 4.0 mm and 1,017 periodontally healthy controls. Probing pocket depth measurements were performed between 1 and 12 months post-partum. In this population, the A allele of rs1946518 and the C allele of rs187238 are more common. After adjustment for age, education, smoking, and use of an interdental brush, compared with subjects with the AA or AC genotype of SNP rs1946518, those with the CC genotype had a significantly reduced risk of periodontitis (adjusted odds ratio = 0.54, 95% confidence interval = 0.29-0.97). No significant association was observed between rs187238 and the risk of periodontitis. Our study did not reveal any evidence of interaction between the IL18 polymorphisms and smoking. Our findings indicate that the IL18 promoter SNP, rs1946518, is a potential risk factor of periodontitis among young Japanese women.

Calcium intake is associated with decreased prevalence of periodontal disease in young Japanese women.

BACKGROUND: We investigated the relationships between calcium intake and the prevalence of periodontal disease. METHODS: This cross-sectional study included 1162 women with a mean age of 31.5 years. Information on dietary factors was collected using a diet history questionnaire during pregnancy. Oral examinations were performed between one and twelve months postpartum. Periodontal disease was defined as positive if a woman had at least one tooth with a pocket depth of 4.0 mm or deeper. Adjustment was made for age, region of residence, smoking status, toothbrushing frequency, use of an interdental brush, household income, and education. RESULTS: Compared with the lowest quartile of calcium intake, the highest quartile was significantly associated with a lower prevalence of periodontal disease; however, the inverse linear trend fell just short of the significance level: the adjusted odds ratio was 0.53 (95% confidence interval: 0.30-0.94, P for trend =0.07). CONCLUSIONS: Our findings suggest that higher calcium intake may be inversely associated with the prevalence of periodontal disease.

Association between perception of dentist oversupply and expectations of dentistry: a survey of dental graduates in Japan.

BACKGROUND: The perception that there is a surplus of dentists may be an opportunity to explore attractive career options in dentistry in Japan. METHODS: A self-administered questionnaire was mailed to 2,114 graduates of a private dental school in Japan. We asked about the perception of oversupply, rated by a visual analogue scale, work environment factors, potential areas of dentistry and necessary medical subjects for their dental practice. The association of a strong perception of dentist oversupply with work environment factors, dental areas and medical subjects was examined by multivariate logistic regression analyses. RESULTS: The response rate was 66%, and data from 1,203 community dentists were analysed. Most respondents (76%) perceived either a strong or very strong surplus of dentists. A very strong perception was significantly associated with work environment factors, including practising in large cities and earning the second lowest of four levels of annual income, but no further associations were found with either the number of patients treated or with the other two ranges of income. This perception was negatively associated with the number of necessary medical subjects, specifically otorhinolaryngology, but no significant association was seen with the number of potential areas of dentistry. CONCLUSIONS: The negative correlation between the aspiration to acquire medical knowledge and the perception of dentist oversupply under the circumstance of the possibly excessive perception among community dentists invites further research on the benefits of teaching oral medicine to graduate entry students to build future working satisfaction.

[Evaluating the relationship between oral health status in male workers and question item regarding subjective chewing symptoms].

OBJECTIVES: In recent years, the relationship between oral health status and various diseases has been increasingly reported worldwide, leading to a growing understanding of the importance of oral health. This study aimed to investigate the relationship between oral health status, determined after a dental health check-up, and chewing condition, determined via a questionnaire for specific health check-ups with the newly added chewing condition item-When you chew your food, which most accurately describes your chewing-. METHODS: From 20,834 Japanese workers who underwent dental health check-ups and specific health check-ups from April 2018 to March 2019, 4,011 male workers (51.2 ± 6.1 years, range 40-64 years) were extracted for this study. Participants were divided into two groups, the good chewing condition group (GCG) and poor chewing condition group (PCG), according to their responses to a questionnaire regarding chewing conditions. We collected and compared data on subjects' age, smoking status, number of teeth present, number of filled teeth, number of decayed teeth, number of missing teeth with prosthetic treatment, periodontal pockets, gingival bleeding, oral hygiene status, and Eichner's classification. Additionally, to clarify the risk associated with chewing condition, we performed stepwise multiple logistic regression analysis with good chewing condition/poor chewing condition as the dependent variable, and age, smoking status, number of teeth present, number of filled teeth, number of missing teeth with prosthetic treatment, periodontal pockets, oral hygiene status, and Eichner's classification as the independent variables. RESULTS: The result of stepwise multiple logistic regression analyses, the odds ratio (OR) and 95% confidence interval (95% CI) of the factors that remained in the final model were as follows; the number of decayed teeth (OR = 1.18 [95% CI: 1.12-1.24]); periodontal pockets of 3 mm or less vs. 6 mm or more (OR = 1.63 [95% CI: 1.12-2.37]); Eichner's classification A1 vs. A2 (OR = 1.40 [95% CI: 1.08-1.82]), A3 (OR = 1.66 [95% CI: 1.09-2.52]), B1 (OR = 3.38 [95% CI: 2.04-5.61]), B2 (OR = 5.26 [95% CI: 2.46-11.2]), B3 (OR = 4.28 [95% CI: 1.20-15.2]), B4 (OR = 7.59 [95% CI: 1.06-54.5]). CONCLUSIONS: The results of this study suggest a significant association between the newly added "chewing condition" item in the questionnaire for specific health check-ups and oral status; the number of decayed teeth, periodontal pockets, Eichner's classification.

Oral-malodor measurement and intention to quit smoking in men: A before-after study.

INTRODUCTION: Few studies have examined the effect of feedback based on oral-malodor measurements on the motivation to quit smoking. Therefore, this study examined whether oral-malodor measurements were associated with the intention to quit smoking. METHODS: This retrospective, uncontrolled before-after study invited smokers to a workplace health event in 2019 and 2020 to motivate them to quit smoking. They attended seminars on oral health and smoking cessation aids, and then underwent respiratory function and oral-malodor measurements using exhaled and oral cavity air, respectively. Intention to quit smoking was evaluated by answers to questions regarding the intention to quit in the next 1 or 6 months in questionnaires collected before and after the event. This study analyzed 241 men aged 20-54 years (mean: 33.2 ± 10.5) to examine factors associated with the intention to quit in multivariable logistic regression analyses for age, tobacco type (cigarettes and heated-tobacco products), and category of tobacco consumption. RESULTS: Before the event, 8.7%, 17.0%, and 74.3% of smokers had intended to quit in the next month, the next six months, or had no intention to quit, respectively. After the event, the respective percentages were 17.8%, 26.6%, and 55.6%. A higher methyl mercaptan concentration, a volatile sulfide component of oral malodor, was significantly associated with the intention to quit in the next month (adjusted odds ratio, AOR=4.24; 95% CI: 1.52-11.8, p=0.006). The participants with higher daily tobacco consumption were less likely to acquire the intention to quit in the next six months (AOR=0.37; 95% CI: 0.15-0.92, p=0.032). Other variables, such as lung age deficit, exhaled CO concentration, and hydrogen sulfide concentration (another component of oral malodor), were not significantly associated. CONCLUSIONS: Oral-malodor measurement feedback may help motivate men to quit smoking in the next 1 month rather than in the next six months.

[Association between subjective chewing conditions and dietary habits in Japanese workers].

OBJECTIVES: Previous studies on the elderly have reported that they avoid fiber-rich and hard foods in favor of softer foods as chewing ability declines. However, evidence of worker chewing conditions and dietary habits is scarce. This study aimed to clarify the association between chewing conditions and dietary habits in workers. METHODS: The subjects included 6,703 workers (45.6 ± 10.2 years, range 18-64 years) who underwent medical and dental check-ups from April 2018 to March 2019 with no missing data. We classified workers into two groups, those with good chewing conditions (GCC) and those with poor chewing conditions (PCC) according to their responses to the chewing condition item in our questionnaire. We performed logistic regression analysis using the questionnaire dietary habits item response as the objective variable and chewing conditions as the explanatory variable and adjusting for sex, age, number of present teeth, periodontal pocket depth, oral hygiene status, Body Mass Index, smoking habits, alcohol intake, exercise habits, history of present illness, and stages of transtheoretical model. Additionally, we performed subgroup analysis using a similar framework stratified by sex and age groups (under 40 or older). RESULTS: We found significant negative associations with PCC for the following dietary habits (p < .05): Awareness of balanced diet; Regular consumption of dark green and deep yellow vegetables; Eating slowly and chewing well; Frequent consumption of seaweed and small fish; Having three meals at almost at the same time every day; Having breakfast almost every day; Eating protein dishes with every meal; Frequently consuming dairy products; Finishing eating at least two hours before bedtime. Furthermore, we found significant positive associations with PCC for the following items (p < .05): Having on average two or more bottles/cans of juice or coffee a day; Frequently eating heavy meat dishes; Frequently eating deep-fried foods such as fried dishes and pork cutlets; Frequently having instant or processed foods; Eating two or more kinds of Western or Japanese confectioneries or snacks on average a day; Frequently eating salty food; Regularly having snacks or late-night meals. Additionally, similar trends were also observed following subgroup analysis, regardless of sex or age. CONCLUSIONS: This study suggests that workers with PCC may retain undesirable dietary habits, regardless of sex and age. Therefore, it is necessary to expand dental check-ups in the workplace and to promote dental health guidance that targets all workers.

Necessity and readiness for smoking cessation intervention in dental clinics in Japan.

BACKGROUND: The necessity and readiness for smoking cessation intervention in dental clinics was assessed by investigating smoking status and stage of behavior change in patients and the attitudes of dentists toward the effects of smoking on their patients, respectively. METHODS: A self-administered questionnaire was mailed to 1022 dentists randomly selected from the Japanese Dental Association database. The questionnaire survey consisted of 1 section for dentists and 1 for patients aged 20 years or older and was scheduled to be completed at the dentists' clinics on a designated day in February 2008. RESULTS: The response rate to the questionnaire was 78.2% from among target dental clinics and 73.7% and 74.7% for patient and dentist questionnaires, respectively. Data from 11,370 patients and 739 dentists were analyzed. The overall smoking prevalence among the patients (25.1%) was similar to that reported by the National Health and Nutrition Examination Survey, and young female patients had a markedly higher smoking prevalence. More than 70% of patients who smoked were interested in quitting. Although the prevalence of current smoking among dentists (27.1%) was significantly higher than that reported among Japanese physicians (15.0%), approximately 70% of dentists were concerned about the effects of smoking on patient health and prohibited smoking inside their clinic. CONCLUSIONS: Many smokers who were interested in quitting, particularly young women, visited dental clinics, and most dentists believed that smoking was harmful for their patients. These results indicate that smoking cessation intervention in dental settings is necessary and that dentists are ready to provide such interventions.

The effects of cigarette smoking on the salivary and tongue microbiome.

OBJECTIVES: It has been suggested that smoking affects the oral microbiome, but its effects on sites other than the subgingival microbiome remain unclear. This study investigated the composition of the salivary and tongue bacterial communities of smokers and nonsmokers in periodontally healthy adults. METHODS: The study population included 50 healthy adults. The bacterial composition of resting saliva and the tongue coating was identified through barcoded pyrosequencing analysis of the 16S rRNA gene. The Brinkman index (BI) was used to calculate lifetime exposure to smoking. The richness and diversity of the microbiome were evaluated using the t-test. Differences in the proportions of bacterial genera between smokers and nonsmokers were evaluated using the Mann-Whitney U test. The quantitative relationship between the proportions of genera and the BI was evaluated using Pearson's correlation analysis. RESULTS: The richness and diversity of the oral microbiome differed significantly between saliva and the tongue but not between smokers and nonsmokers. The saliva samples from smokers were enriched with the genera Treponema and Selenomonas. The tongue samples from smokers were enriched with the genera Dialister and Atopobium. The genus Cardiobacterium in saliva, and the genus Granulicatella on the tongue, were negatively correlated with BI values. On the other hand, the genera Treponema, Oribacterium, Dialister, Filifactor, Veillonella, and Selenomonas in saliva and Dialister, Bifidobacterium, Megasphaera, Mitsuokella, and Cryptobacterium on the tongue were positively correlated with BI values. CONCLUSIONS: The saliva and tongue microbial profiles of smokers and nonsmokers differed in periodontally healthy adults. The genera associated with periodontitis and oral malodor accounted for high proportions in saliva and on the tongue of smokers without periodontitis and were positively correlated with lifetime exposure to smoking. The tongue might be a reservoir of pathogens associated with oral disease in smokers.

Job Satisfaction and Perceived Importance of Oral Medicine Amongst Dentists.

BACKGROUND: Compounded by the needs of an aging society, interactions between oral condition and systemic diseases may require that dentists pursue additional training in oral medicine beyond that received in dental school. The purpose of this study was to investigate whether pursuing oral medicine professional education is recognised by dental practitioners as an important factor regarding job satisfaction. METHODS: A questionnaire was mailed to 1,379 dental practitioners in Japan, along with a follow-up survey to assess repeatability, in 2017. The questionnaire consisted of 19 items/questions related to the respondents' attributes and job satisfaction (5 items), willingness to learn oral medicine (4 items), willingness to learn more about dentistry (4 items), and willingness to contribute to society (6 items). Representative questions were extracted via binomial logistic regression analysis. Multivariable logistic regression analysis was performed to assess the relationships between job satisfaction and the explanatory variables. RESULTS: Amongst 337 respondents, multivariable logistic regression analysis showed an association between strong job satisfaction (n = 126, 37%) and willingness to learn more about oral medicine and dentistry and contribute to society, with odds ratios (95% confidence interval) of 4.22 (1.84-9.68), 3.16 (1.16-8.62), and 7.32 (3.14-17.06) and κ values of 0.38, 0.58, and 0.51, respectively. CONCLUSIONS: Our results from dental practitioners suggest additional benefits of oral medicine professional education for future job satisfaction.

Application of Lactobaillus salivarius WB21 to the Oral Care of Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Crossover Comparative Study.

OBJECTIVE: A randomized, double-blind, placebo-controlled crossover comparative study was conducted in a healthy older population to assess the usefulness of Lactobacillus salivarius WB21 (WB21) ingestion for oral self-care. METHODS: The study population included 33 healthy older individuals who were randomly divided into two groups (A and B). Group A consumed WB21 tablets during the first two months and placebo tablets during the following two months. Group B consumed placebo tablets during the first two months and WB21 tablets during the following two months. Before and after ingestion, oral examination, mouth odor test, and saliva collection were performed a total of four times. In addition, health conditions were obtained from a questionnaire survey at the study's midpoint. RESULTS: Two people in group A and one person in group B dropped out of the study. Thus, 15 people in group A and 15 people in group B were included in the analysis. Over two months of WB21 ingestion, salivary secretory IgA increased significantly (p = 0.047) and tongue coating score decreased significantly (p = 0.013). The plaque index, bleeding on probing, and mouth odor levels (H2S and CH3SH concentrations) did not change. During the 6-month study period, no caries, deterioration of periodontitis, or changes in oral health or systemic subjective symptoms were observed. CONCLUSION: Continuous ingestion of WB21-containing tablets may promote self-care of the teeth and mouths of healthy older adults. TRIAL REGISTRATION: R000028335 (UMIN-CTR).

A multicentre tobacco cessation intervention study in the dental setting in Japan.

OBJECTIVE: The objective of this study was to assess the efficacy of a tobacco cessation intervention conducted by different dental specialists directed at a group of patients with tobacco-related oral diseases or undergoing implant treatment. METHODS: The study design was a multicentre, nonrandomized prospective cohort study to examine the effects of smoking cessation. The target patients were current smokers (aged ≥20 years) with an oral potentially malignant disorder or periodontitis and those seeking dental implants. A total of 74 patients were enrolled in the study. All dental specialists who participated in the trial completed an e-learning Japan Smoking Cessation Training Outreach Project (J-STOP) tobacco cessation education programme. Nicotine dependence was evaluated by the Fagerstrom Test for Nicotine Dependence. Cessation status was verified biochemically by measurement of salivary cotinine or exhaled carbon monoxide. Tobacco cessation intervention was implemented for 8 weeks with or without nicotine replacement therapy with follow-up for 12 months. RESULTS: A total of 61 patients agreed to the tobacco cessation intervention. The mean biochemically confirmed tobacco abstinence rate was 37.7% at month 3, 34.4% at month 6, and 32.8% at month 12. The highest rate of biochemically confirmed tobacco abstinence at month 12 was among patients receiving implant treatment (42.9%) followed by patients with oral potentially malignant disorder (37.1%), and those with periodontitis (21.1%). CONCLUSION: This interventional study demonstrates the challenges encountered and the feasibility of tobacco cessation intervention among Japanese patients attending dental specialists who had completed an e-learning course on smoking cessation. Making tobacco cessation an integral part of patient management by dental specialists requires further evaluation.

Causal assessment of smoking and tooth loss: a systematic review of observational studies.

BACKGROUND: Tooth loss impairs oral function. The aim of the present review was to evaluate the causal association between smoking and tooth loss on the basis of high-quality studies. METHODS: Relevant literature was searched and screened, and the methodological quality was assessed. Information on the strength of the association between smoking and tooth loss, the dose-response relationship and natural experimental data was collected and evaluated with respect to consistency and study design. RESULTS: Our literature search yielded 496 citations, and 6 cross-sectional and 2 cohort high-quality studies examining 58,755 subjects in four countries. All studies reported significant associations, although the strength of the association was usually moderate. Four studies reported dose-response relationships between exposure to smoking and the risk of developing tooth loss. A decrease in the risk of tooth loss for former smokers was evident in six studies. Interpretation of evidence for each element was consistent, despite some shortcomings regarding study type and population. CONCLUSIONS: Based on the consistent evidence found with the existing biological plausibility, a causal association between smoking and tooth loss is highly likely. Further studies using a cohort design and different populations are necessary to confirm this association.

Impact of a tobacco curriculum on smoking behaviour and attitudes toward smoking in dental students in Japan: a three-year follow-up study.

AIM: Dental professionals have the potential to influence global smoking rates. This study evaluated the impact of a tobacco curriculum on smoking behaviour and attitudes toward smoking in dental students. METHODS: Immediately before and three years after the implementation of a tobacco curriculum with a no-smoking policy, a questionnaire was administered to students to obtain information about their smoking behaviour and attitudes toward smoking. RESULTS: The number of students who responded to the questionnaire was 580 in 2003 and 554 in 2006. The smoking rate decreased significantly from 35% in 2003 to 26% in 2006; however, analysis of data for each school year suggested that this was due to the prevention of smoking initiation rather than quitting smoking. Attitudes toward patient smoking and public policy were more positive in non-smokers than in current smokers. Improvement in attitudes toward patient smoking was smaller in current smokers than in non-smokers. Little improvement occurred in attitudes toward public policy in both non- and current smokers. CONCLUSIONS: Implementation of a tobacco curriculum was effective in preventing smoking initiation and improving attitudes toward patient smoking in students. Further measures are necessary to improve attitudes toward public policy and to discourage smoking among students.

Effects of eradication of Helicobacter pylori on oral malodor and the oral environment: a single-center observational study.

OBJECTIVE: Although a relationship between Helicobacter pylori and oral malodor has been suggested, it remains to be confirmed. One reason for this is that many studies assess oral malodor subjectively. Another reason for the uncertainty is that the reduction in oral malodor may be due to the effect of antibiotics on the oral microbiota. In this study, changes in oral malodor along with the eradication treatment of H. pylori were investigated by organoleptic test and gas chromatography. In addition, the salivary bacterial composition and clinical parameters were analyzed. RESULTS: The organoleptic test score, hydrogen sulfide and dimethyl sulfide concentrations, and all clinical parameters except for tongue-coating score were significantly decreased at 1 week compared with baseline. Although antibiotic treatment also altered the overall composition of the salivary bacterial population, it had recovered at 7 weeks. On the date that H. pylori was determined to have been eradicated from all of the subjects (7 weeks after treatment), only the organoleptic test score was significantly lower compared with baseline. The hydrogen sulfide and dimethyl sulfide concentrations were non-significantly lower than those at baseline.

Novel oral biomarkers predicting oral malodor.

OBJECTIVE: We sought new markers to predict oral malodor. STUDY DESIGN: Seventy-five adults complaining of oral malodor were classified into 3 groups clinically: no oral malodor, physiologic oral malodor, and periodontitis-derived oral malodor. In addition to conventional clinical parameters, 7 salivary components, occlusal force, and lip-closing force were compared among the groups. RESULTS: Concerning the salivary components, cariogenic bacteria, occult blood, leukocytes, and ammonia differed significantly among the groups. Multiple logistic regression analyses indicated that tongue-coating scores and ammonia levels were significantly associated with genuine oral malodor, including physiologic oral malodor and periodontitis-derived oral malodor, and the tongue-coating score, plaque index, and occult blood level were significantly associated with periodontitis-derived oral malodor. Occlusal force and lip-closing force did not differ among the groups. However, there was a statistically significant interaction between occlusal force and lip-closing force in oral malodor in women (P = .019). CONCLUSIONS: Novel salivary markers, ammonia levels, and occult blood levels may predict genuine oral malodor and periodontitis-derived oral malodor, respectively. An interaction effect between occlusal force and lip-closing force on oral malodor was identified in women.

A multicenter prospective cohort study on the effect of smoking cessation on periodontal therapies in Japan.

Few prospective studies have reported the effects of periodontal therapy on patients who attempted to quit smoking. This study aimed to assess how smoking cessation affects periodontal therapy. Twenty-five smokers with periodontitis were investigated by dividing them into two groups, a smoking cessation support group and a continued smoking group. Those in the support group received counseling and nicotine replacement therapy, followed by periodontal treatment conducted by dentists who had completed an e-learning course on smoking cessation. Clinical parameters were measured at baseline, 3, and 6 months. Most clinical parameters improved for those in the smoking cessation support group. There were no significant improvements in bleeding on probing (BOP) or the number of severe periodontal disease sites in the continued smoking group. Probing pocket depth (PPD) and clinical attachment levels (CAL) at sites that received scaling and root planing (SRP) significantly improved in all subjects. BOP did not improve at reevaluation in the smoking relapse subgroup. Patients in the smoking cessation support program led by dental professionals showed more improvement in BOP than those in the continued smoking group.