Relationship between acetaldehyde concentration in mouth air and characteristics of microbiota of tongue dorsum in Japanese healthy adults: a cross-sectional study.

OBJECTIVE: Acetaldehyde, associated with consumption of alcoholic beverages, is known to be a carcinogen and to be related to the tongue dorsum. The aim of this study was to investigate the relationship between acetaldehyde concentration in mouth air and bacterial characteristics on the tongue dorsum. METHODOLOGY: Thirty-nine healthy volunteers participated in the study. Acetaldehyde concentrations in mouth air were evaluated by a high-sensitivity semiconductor gas sensor. A 16S rRNA gene sequencing technique was used to compare microbiomes between two groups, focusing on the six samples with the highest acetaldehyde concentrations (HG) and the six samples with lowest acetaldehyde concentrations (LG). RESULTS: Acetaldehyde concentration increased in correlation with the increase in bacterial count (p=0.048). The number of species observed in the oral microbiome of the HG was higher than that in the oral microbiome of the LG (p=0.011). The relative abundances of Gemella sanguinis, Veillonella parvula and Neisseria flavescens in the oral microbiome of the HG were higher than those in the oral microbiome of the LG (p<0.05). CONCLUSION: Acetaldehyde concentration in mouth air was associated with bacterial count, diversity of microbiome, and relative abundance of G. sanguinis, V. parvula, and N. flavescens.

Awareness of Clenching and Underweight are Risk Factors for Onset of Crowding in Young Adults: A Prospective 3-Year Cohort Study.

Bruxism is a parafunctional activity that can seriously affect quality of life. Although bruxism induces many problems in the oral and maxillofacial area, whether it contributes to the onset of malocclusion remains unclear. The purpose of this prospective cohort study was to investigate the association between the onset of malocclusion and awareness of clenching during the daytime in young adults. Among 1,092 Okayama University students who underwent normal occlusion at baseline, we analysed 238 who had undergone a dental examination and had complete data after 3 years (2013⁻2016). We also performed subgroup analysis to focus on the association between awake bruxism and the onset of crowding (n = 216). Odds ratios (ORs) were calculated using multivariate logistic regression analyses. The incidences of malocclusion and crowding were 53.8% and 44.5%, respectively. In multivariate logistic regression, awareness of clenching was a risk factor for crowding (OR: 3.63; 95% confidence interval [CI]: 1.08⁻12.17). Moreover, underweight (body mass index < 18.5 kg/m²) was related to the onset of malocclusion (OR: 2.34; 95%CI: 1.11⁻4.92) and crowding (OR: 2.52, 95%CI: 1.25⁻5.76). These results suggest that awareness of clenching during the daytime and underweight are risk factors for the onset of crowding in young adults.

The level of salivary lactate dehydrogenase as an indicator of the association between gingivitis and related factors in Japanese university students.

The aim of this study was to investigate the association between the presence of gingivitis estimated using the salivary level of lactate dehydrogenase (LD) and related factors in young Japanese adults. Data from 1,915 participants (21.4 ± 2.5 years) were analyzed. Unstimulated saliva was collected from each participant and the salivary LD level was evaluated using a commercially available test kit with an integer scale ranging from 1 to 10. Gingivitis was defined as the LD level of ≥8. The number of permanent teeth, the simplified oral hygiene index (OHI-S), the presence of partially erupted molars and body mass index were recorded. Additionally, participants answered a questionnaire. The percentage of male participants, the number of permanent teeth, the OHI-S and the presence of partially erupted molars were higher, whereas the proportion receiving dental check-ups was lower in the gingivitis group (n = 88, 4.6%) than in the healthy group. Logistic regression analysis showed that gingivitis was significantly associated with OHI-S (OR: 2.68, 95% CI: 1.94-3.69) and receiving dental checkups (OR: 0.31, 95% CI: 0.10-0.99). The present findings indicated that the OHI-S and receiving dental checkups were significantly associated with gingivitis, as assessed by the salivary LD level, in this cohort.

Relationship between acetaldehyde concentration in mouth air and characteristics of microbiota of tongue dorsum in Japanese healthy adults: a cross-sectional study

Abstract Acetaldehyde, associated with consumption of alcoholic beverages, is known to be a carcinogen and to be related to the tongue dorsum. Objective The aim of this study was to investigate the relationship between acetaldehyde concentration in mouth air and bacterial characteristics on the tongue dorsum. Methodology Thirty-nine healthy volunteers participated in the study. Acetaldehyde concentrations in mouth air were evaluated by a high-sensitivity semiconductor gas sensor. A 16S rRNA gene sequencing technique was used to compare microbiomes between two groups, focusing on the six samples with the highest acetaldehyde concentrations (HG) and the six samples with lowest acetaldehyde concentrations (LG). Results Acetaldehyde concentration increased in correlation with the increase in bacterial count (p=0.048). The number of species observed in the oral microbiome of the HG was higher than that in the oral microbiome of the LG (p=0.011). The relative abundances of Gemella sanguinis, Veillonella parvula and Neisseria flavescens in the oral microbiome of the HG were higher than those in the oral microbiome of the LG (p<0.05). Conclusion Acetaldehyde concentration in mouth air was associated with bacterial count, diversity of microbiome, and relative abundance of G. sanguinis, V. parvula, and N. flavescens.

Type D personality and periodontal disease in university students: A prospective cohort study.

The purpose of this prospective cohort study was to investigate whether Type D personality was related to periodontal disease in Japanese university students. Among students ( n = 600) who were interested in receiving oral health examinations, logistic regression analysis showed that the risk of developing periodontal disease during a 3-year period was associated with body mass index ⩾ 25 (odds ratio: 2.543; 95% confidence interval: 1.297-4.989; p = 0.007) and Type D personality (odds ratio: 1.473; 95% confidence interval: 1.027-2.111; p = 0.035). In this short-term prospective cohort study, a significant association between periodontal disease and Type D personality was observed in Japanese university students.

Associations between dental knowledge, source of dental knowledge and oral health behavior in Japanese university students: A cross-sectional study.

The aim of this study was to investigate the associations between dental knowledge, the source of dental knowledge and oral health behavior in a group of students at a university in Japan. A total of 2,220 university students (1,276 males, 944 females) volunteered to undergo an oral examination and answer a questionnaire. The questionnaire assessed dental knowledge, the source of dental knowledge and oral health behavior (e.g., daily frequency of tooth brushing, use of dental floss and regular dental checkups). The odds ratio and 95% confidence interval for oral health behavior based on dental knowledge and source of dental knowledge were calculated using logistic regression models. Of the participants, 1,266 (57.0%) students obtained dental knowledge from dental clinics, followed by school (39.2%) and television (29.1%). Logistic regression analyses indicated that use of dental floss was significantly associated with source of dental knowledge from dental clinics (P = 0.006). Receiving regular dental checkups was significantly associated with source of dental knowledge; the positive source was dental clinic (P < 0.001) and the negative sources were school (P = 0.004) and television (P = 0.018). Dental clinic was the most common source of dental knowledge and associated with better oral health behavior among the Japanese university students in this study.

Validity of a New Kit Measuring Salivary Lactate Dehydrogenase Level for Screening Gingivitis.

Aim. The aim of this study was to determine the usefulness of a new kit that can evaluate salivary lactate dehydrogenase (LD) level in real time for screening gingivitis. Materials and Methods. The study included 70 systemic healthy volunteers [29 males and 41 females; mean age ± SD: 24.1 ± 2.6 years]. Resting saliva was collected from each participant and LD level was evaluated in real time using the kit (a color-changing sheet with an integer scale ranging from 1 to 10). A dentist measured probing pocket depth, clinical attachment level, and the proportion of sites with bleeding on probing (% BOP) at six sites on all teeth. Gingivitis was diagnosed when the BOP value was ≥20%. Results. Salivary LD level was positively correlated with mean % BOP (odds ratio: 1.47, 95% confidence interval: 1.132-1.916, and P < 0.001) in a logistic regression model. The sensitivity and specificity of the kit were 0.89 and 0.98, respectively, at a cut-off value of 8.0 for LD level. Conclusions. The new kit for measurement of salivary LD level may be a useful tool to screen for gingivitis in young adults, which contributes to early detection of future periodontitis.

Associations among oral health-related quality of life, subjective symptoms, clinical status, and self-rated oral health in Japanese university students: a cross-sectional study.

BACKGROUND: The present study aimed to elucidate the associations among self-rated oral health, clinical oral health status, oral health behaviors, subjective oral symptoms, and oral health-related quality of life (OHRQoL) in a group of Japanese university students. METHODS: Of 2051 participants, 2027 (98.83%) students received an optional oral examination and answered a questionnaire including items regarding age, sex, self-rated oral health, oral health behaviors, subjective oral symptoms, and OHRQoL [The Oral Health Impact Profile (OHIP)-14]. On oral examination, the decayed, missing, and filled teeth (DMFT) score, Community Periodontal Index (CPI), the percentage of teeth showing bleeding on probing (%BOP), and malocclusion were recorded. Structural equation modelling (SEM) analysis was used to test associations. RESULTS: The mean score (± SD) of OHIP-14 was 1.92 ± 5.47. In the SEM analysis, the final model showed that self-rated oral health, oral pain, malocclusion, and the DMFT score were directly associated with the OHRQoL, and subjective symptoms of temporomandibular disorders (TMD) and recurrent aphthous stomatitis were both directly and indirectly associated (p < 0.05). CPI, %BOP, and oral health behaviors were excluded from the final model. CONCLUSIONS: OHRQoL was associated with self-related oral health, subjective symptoms of TMD, oral pain and stomatitis, DMFT, and malocclusion in this group of Japanese university students.