Association between oral health and thyroid disorders: A population-based cross-sectional study.

OBJECTIVES: In this study, we aimed to determine the relationship between oral health status and thyroid dysfunction. METHODS: A population-based cross-sectional analysis using data from the Korean National Health and Nutrition Examination Survey (KNHNES) was performed. We investigated the association between oral health-related parameters and the prevalence of thyroid diseases. In addition, the relationship between oral health status and thyroid function test (TFT) results was analyzed. One-way analysis of variances or chi-square test was used for comparisons between oral health-related parameters and presence of thyroid diseases. Univariable and multivariable logistic regression analyses were conducted to evaluate the associations between participants' characteristics including oral health-related parameters and the abnormal results of TFTs. RESULTS: A total of 18,034 adults were surveyed. Histories of thyroid diseases were found to be more common in people who brushed their teeth frequently or used oral hygiene products. However, histories of periodontitis and community periodontal index (CPI) did not show significant associations with histories of thyroid diseases. Among 14,860 participants without history of thyroid disorders, people having higher CPI values demonstrated higher probabilities of abnormal TFTs (OR 1.381, 95% CI 1.241-1.537, p < .0001); however, statistical significance was not found after adjusting for the other variables. CONCLUSIONS: Our study demonstrated that good oral health-related behavior was associated with more frequent thyroid disease history. High CPI showed a significant association with TFT abnormalities; however, the significance of this association became lower when other variables such as age and sex were adjusted. Further studies will be needed to determine how the control of oral health-related conditions actually has a causal relationship with thyroid disease/dysfunction through prospective cohort studies.

Clinical Validation of Dental Implant Stability by Newly Designed Damping Capacity Assessment Device during the Healing Period.

Background and Objectives: To evaluate the stability of a dental implant and the effectiveness of a newly designed damping capacity assessment device by improving the number of blows and strength evaluated by a prospective clinical study. Materials and Method: The stability of dental implants was measured in 50 implants in a total of 38 patients. Measurements were performed using Anycheck and Periotest M devices, twice in total, divided into buccal and lingual directions. In addition, measurements were performed on the day of surgery, two weeks, one month, two months, and three months after surgery for a total of five times. After the standardization of the measured values, the differences and changes over time for each device were observed. Result: No difference in standardized values between the two devices was observed at any time point. In both devices, stability decreased at two weeks postoperatively but gradually increased thereafter. No differences were observed in the values according to the measurement direction. Conclusions: The damping capacity of Anycheck was similar to that of Periotest M. After a slight decrease in stability two weeks after implant placement, implant stability increased over time.

Shift work sleep disorder is closely associated with an increased risk for periodontal disease.

AIM: This study aimed to investigate the association between work patterns and periodontal disease. MATERIALS AND METHODS: Data were collected from the Korea National Health and Nutrition Examination Survey between 2007 and 2012, and data from 22,508 subjects aged ≥19 years were included. An individual's work pattern was classified as either daytime or shift work. Sleep duration was categorized into three ranges: ≤5, 6-8, and ≥9 h/day. A multivariate logistic regression model was used to determine the adjusted odds ratio (OR) for CPI (Community Periodontal Index) ≥3. The CONTRAST statement was used to show the interaction effect of work patterns and sleep duration. RESULTS: The adjusted OR of shift work was 2.168 (CI: 1.929-2.438, p < .0001). Participants who sleep ≤5 or ≥9 h/day showed ORs 0.735 and 0.663, respectively (p = .0181). Interaction effect analysis revealed that the work pattern had a strong influence on periodontal condition when combined with the sleep amount. Shift workers with ≤5 or ≥ 9 h of sleep showed significantly increased ORs for CPI ≥3 (2.1406 and 2.3251, respectively, p < .0001). The ORs for daytime workers were comparable to the original values (≤5: 0.7348, p = .0292; ≥9: 0.6633, p = .0428). CONCLUSION: Altered sleep patterns caused by shift work have more influence on periodontal disease than sleep duration.

TLR2 and the NLRP3 inflammasome mediate IL-1ß production in Prevotella nigrescens-infected dendritic cells.

Prevotella nigrescens is an oral pathogen that is frequently observed in the subgingival plaque of periodontitis patients. Interleukin-1ß (IL-1ß) is known to be involved in the immunopathology of periodontal diseases and has been implicated in the destruction of bone. In this study, we investigated the mechanism of IL-1ß production by P. nigrescens in murine bone marrow-derived dendritic cells (BMDCs). Our results showed that a host receptor, Toll-like receptor 2 (TLR2), but not TLR4 is required for pro-IL-1ß induction and nucleotide-binding oligomerization domain like receptor pyrin domain containing 3 (NLRP3) priming in BMDCs in response to P. nigrescens and activation of the NLRP3 inflammasome is necessary for processing of pro-IL-1ß into mature IL-1ß. In addition, an inhibitor assay revealed that production of reactive oxygen species, P2X7R activity, and release of cathepsin B are involved in IL-1ß production in BMDCs in response to P. nigrescens.

Effects of Lactobacillus reuteri MG5346 on Receptor Activator of Nuclear Factor-Kappa B Ligand (RANKL)-Induced Osteoclastogenesis and Ligature-Induced Experimental Periodontitis Rats.

Effects of culture supernatants of Lactobacillus reuteri MG5346 (CS-MG5346) on receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclastogenesis were examined. CS-MG5346 treatment up to 400 µg/mL significantly reduced tartrate-resistant acid-phosphatase (TRAP) activity, the phenotype biomarker of osteoclast, without affecting cell viability. CS-MG5346 inhibited the expression of osteoclast specific transcriptional factors (c-fos and nuclear factor-activated T cells c1) and their target genes (TRAP, cathepsin, and matrix metallo-proteinase-9) in a dose-dependent manner (p<0.05). The administration of L. reuteri MG5346 (2×108 CFU/day) for 8 wks significantly improved furcation involvement, but no difference was observed in alveolar bone loss in ligature-induced experimental periodontitis rats. The elevated RANKL/ osteoprotegerin ratio, the biomarker of periodontitis, was significantly lowered in the gingival tissue by administration of L. reuteri MG5346 (p<0.05). L. reuteri MG5346 showed excellent stability in simulated stomach and intestinal fluids and did not have antibiotic resistance. Based on the results, L. reuteri MG5346 has the potential to be a promising probiotic strain for oral health.

Periodontitis of maxillary teeth screened by community periodontal index is associated with chronic rhinosinusitis defined by EPOS 2020 guideline.

We aimed to evaluate the association between periodontitis in the upper jaw and chronic rhinosinusitis (CRS) using the nationwide Korean National Health and Nutrition Examination Survey (KNHANES) data. In this cross-sectional study, data of KNHANES participants enrolled between 2008 and 2012 were reviewed. Periodontitis of the upper teeth was diagnosed by dentists according to the community periodontal index with standardized methods. CRS was diagnosed by otorhinolaryngologists according to the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 with nasal endoscopy findings. We also evaluated the association between periodontitis and CRS according to smoking and drinking status. Univariate and multivariate logistic regression analyses were performed. Overall, 28,761 participants were eligible for analysis, and 210 were diagnosed with CRS. Periodontitis was associated with CRS diagnosis (odds ratio [OR] = 1.391, 95% confidence interval [CI] = 1.013-1.912). Non-drinkers showed no significant association between periodontitis and CRS (OR = 1.142, 95% CI 0.746-1.749). However, among drinkers, periodontitis was significantly associated with CRS (OR = 1.733, 95% CI 1.091-2.753). The number of smokers with CRS was not statistically sufficient and a logistic regression model based on smoking status could not be generated. Individuals with periodontitis in the upper jaw may need to consult an otorhinolaryngologist for comorbid CRS especially according to drinking status.

Influence of shift work on periodontitis according to the occupation group.

This study aimed to investigate the effects of shift work on periodontal disease in blue-and white-collar workers and to examine the interaction effects between occupation and work patterns. Data were collected from the Korea National Health and Nutrition Examination Survey conducted by the Korean Ministry of Health and Welfare for a total of nine years from 2007 to 2015. Participants with missing outcome variables were excluded from the analysis and a total of 32,336 participants were included in the final analysis. Univariable odds ratios (OR) were calculated using a logistic regression model with 95% confidence interval (CI). A multivariable logistic regression analysis was performed using the backward elimination method. The CONTRAST statement was used to analyze the interaction effect between occupation and work patterns. Multivariable logistic regression analysis revealed that interaction effects are present between the terms, occupational type and work pattern. Crude OR of shift work for periodontitis was 1.269 [CI 1.213-1.327, P < 0.05]. However, following adjustment for multiple confounding factors and the interaction effect term considered, this OR (1.269) increased to 1.381 [CI 1.253-1.523] in white-collar group while it decreased to 1.198 [1.119-1.283] in blue-collar. Crude OR of blue-collar (OR = 3.123, CI 2.972-3.281, P < 0.05) decreased to 1.151 [CI 1.049-1.262] when interaction effect to the shift work was considered. Shift work pattern increases the risk for periodontitis and this adverse effect is greater when white-collar workers are engaged comparing to blue-collar. The result of this study suggests that 24/7 lifestyle of the modern society poses health risks to the relevant people and the potential harm can be greater to white-collar workers.

Virtual Versus Light Microscopy Usage among Students: A Systematic Review and Meta-Analytic Evidence in Medical Education.

BACKGROUND: The usage of whole-slide images has recently been gaining a foothold in medical education, training, and diagnosis. OBJECTIVES: The first objective of the current study was to compare academic performance on virtual microscopy (VM) and light microscopy (LM) for learning pathology, anatomy, and histology in medical and dental students during the COVID-19 period. The second objective was to gather insight into various applications and usage of such technology for medical education. MATERIALS AND METHODS: Using the keywords "virtual microscopy" or "light microscopy" or "digital microscopy" and "medical" and "dental" students, databases (PubMed, Embase, Scopus, Cochrane, CINAHL, and Google Scholar) were searched. Hand searching and snowballing were also employed for article searching. After extracting the relevant data based on inclusion and execution criteria, the qualitative data were used for the systematic review and quantitative data were used for meta-analysis. The Newcastle Ottawa Scale (NOS) scale was used to assess the quality of the included studies. Additionally, we registered our systematic review protocol in the prospective register of systematic reviews (PROSPERO) with registration number CRD42020205583. RESULTS: A total of 39 studies met the criteria to be included in the systematic review. Overall, results indicated a preference for this technology and better academic scores. Qualitative analyses reported improved academic scores, ease of use, and enhanced collaboration amongst students as the top advantages, whereas technical issues were a disadvantage. The performance comparison of virtual versus light microscopy meta-analysis included 19 studies. Most (10/39) studies were from medical universities in the USA. VM was mainly used for teaching pathology courses (25/39) at medical schools (30/39). Dental schools (10/39) have also reported using VM for teaching microscopy. The COVID-19 pandemic was responsible for the transition to VM use in 17/39 studies. The pooled effect size of 19 studies significantly demonstrated higher exam performance (SMD: 1.36 [95% CI: 0.75, 1.96], p < 0.001) among the students who used VM for their learning. Students in the VM group demonstrated significantly higher exam performance than LM in pathology (SMD: 0.85 [95% CI: 0.26, 1.44], p < 0.01) and histopathology (SMD: 1.25 [95% CI: 0.71, 1.78], p < 0.001). For histology (SMD: 1.67 [95% CI: -0.05, 3.40], p = 0.06), the result was insignificant. The overall analysis of 15 studies assessing exam performance showed significantly higher performance for both medical (SMD: 1.42 [95% CI: 0.59, 2.25], p < 0.001) and dental students (SMD: 0.58 [95% CI: 0.58, 0.79], p < 0.001). CONCLUSIONS: The results of qualitative and quantitative analyses show that VM technology and digitization of glass slides enhance the teaching and learning of microscopic aspects of disease. Additionally, the COVID-19 global health crisis has produced many challenges to overcome from a macroscopic to microscopic scale, for which modern virtual technology is the solution. Therefore, medical educators worldwide should incorporate newer teaching technologies in the curriculum for the success of the coming generation of health-care professionals.

Withaferin A inhibits inflammatory responses induced by Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans in macrophages.

Periodontitis is a progressive chronic inflammatory disease and a major cause of tooth loss in humans. As a withanolides, withaferin A (WA) is known to exhibit strong anti­inflammatory activity. The present study examined whether WA inhibited inflammatory responses in macrophages in response to two representative periodontal pathogens, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans. Murine bone marrow­derived macrophages (BMDMs) were used in this study and cytokine production in culture supernatants was measured by enzyme­linked immunosorbent assays. Western blot analysis was performed to determine the activation of nuclear factor­κB and mitogen­activated protein kinases (MAPKs) and the expression of inducible nitric oxide synthase (iNOS), toll­like receptor (TLR) 2 and TLR4. The production of nitric oxide (NO) was determined by the Griess reaction. WA treatment was shown to decrease interleukin (IL)­6 and tumor necrosis factor (TNF)­α production in BMDMs in response to F. nucleatum and A. actinomycetemcomitans in a dose­dependent manner. The phosphorylation of IκB­α and MAPKs (p38, extracellular signal­regulated kinases and c­Jun N­terminal kinases) induced by F. nucleatum and A. actinomycetemcomitans was also inhibited by WA. F. nucleatum and A. actinomycetemcomitans induced iNOS expression and NO production in BMDMs, which was inhibited by WA in a dose­dependent manner. WA also reduced endogenous and induced expression of TLR2 and TLR4 in these cells. These results suggest that WA may be a potential therapeutic agent or preventive additive for periodontitis control.