The relationship between gastroesophageal reflux disease and chronic periodontitis

Microbial functional pathways based on metatranscriptomic profiling enable effective saliva-based health assessments for precision wellness

It is increasingly recognized that an important step towards improving overall health is to accurately measure biomarkers of health from the molecular activities prevalent in the oral cavity. We present a general methodology for computationally quantifying the activity of microbial functional pathways using metatranscriptomic data. We describe their implementation as a collection of eight oral pathway scores using a large salivary sample dataset (n = 9350), and we evaluate score associations with oropharyngeal disease phenotypes within an unseen independent cohort (n = 14,129). Through this validation, we show that the relevant oral pathway scores are significantly worse in individuals with periodontal disease, acid reflux, and nicotine addiction, compared with controls. Given these associations, we make the case to use these oral pathway scores to provide molecular health insights from simple, non-invasive saliva samples, and as molecular endpoints for actionable interventions to address the associated conditions.

Association of periodontitis with gastrointestinal tract disorders: A bidirectional Mendelian randomization study

BACKGROUND

The bidirectional link of periodontitis (PD) and gastrointestinal tract (GIT) disorders has been investigated in previous epidemiological studies; however, the conclusions still remain controversial. The aim of this study was to comprehensively explore the bidirectional causal effect between PD and various GIT diseases.

METHODS

Based on summary-level data of genome-wide association studies (GWASs), a two-sample bidirectional Mendelian randomization (MR) study was undertaken. Single-nucleotide polymorphisms (SNPs) associated with PD or GIT disorders (chronic gastritis [CG], gastric ulcer [GU], duodenal ulcer [DU], gastroesophageal reflux disease [GERD], irritable bowel syndrome [IBS], and diverticular disease of the intestine [DI]) in GWASs were applied as exposure. The primary method employed was the inverse-variance weighted (IVW) method, and several sensitivity analyses were performed to investigate potential pleiotropy.

RESULTS

With regard to the investigation of the causality between PD and GIT disorders, the IVW method revealed that there is a causal impact of PD on GU (odds ratio [OR] 1.088; 95% confidence interval [CI], 1.036-1.141; adjusted p = 0.004) and DI (OR 0.938; 95% CI, 0.911-0.965; adjusted p = 0.000). However, no significant genetic liability was observed for the causal effect of PD on CG, DU, GERD, and IBS. Furthermore, the primary analysis did not demonstrate a causal effect of GIT disorders on PD.

CONCLUSION

This MR study suggests that PD may be associated with an increased risk of GU and a reduced risk of DI, with possibly limited clinical relevance. Further studies are needed to support the conclusions of this MR study.

Identifying causal relationships between gastroesophageal reflux and extraesophageal diseases: A Mendelian randomization study

Traditional observational and in vivo studies have suggested an etiological link between gastroesophageal reflux disease (GERD) and the development of extraesophageal diseases (EEDs), such as noncardiac chest pain. However, evidence demonstrating potential causal relationships is lacking. This study evaluated the potential causal relationship between GERD and EEDs, including throat and chest pain, asthma, bronchitis, chronic rhinitis, nasopharyngitis and pharyngitis, gingivitis and periodontal disease, cough, using multiple Mendelian randomization (MR) methods, and sensitivity analysis was performed. The Mendelian randomization Pleiotropy RESidual Sum and Outlier and PhenoScanner tools were used to further check for heterogeneous results and remove outliers. MR with inverse-variance weighted (IVW) showed a significant causal relationship between GERD and EEDs after Bonferroni correction. IVW results indicated that GERD increased the risk of chronic rhinitis, nasopharyngitis and pharyngitis (odds ratio [OR] = 1.482, 95% confidence interval [CI] = 1.267-1.734, P < .001], gingivitis and periodontal disease (OR = 1.166, 95% CI = 1.046-1.190, P = .001), throat and chest pain (OR = 1.585, 95% CI = 1.455-1.726, P < .001), asthma (OR = 1.539, 95% CI = 1.379-1.717, P < .001), and bronchitis (OR = 1.249, 95% CI = 1.168-1.335, P < .001). Sensitivity analysis did not detect pleiotropy. Leave-one-out analysis shows that MR results were not affected by individual single nucleotide polymorphisms. The funnel plot considers the genetic instrumental variables to be almost symmetrically distributed. This MR supports a causal relationship among GERD and EEDs. Precise moderation based on causality and active promotion of collaboration among multidisciplinary physicians ensure high-quality diagnostic and treatment recommendations and maximize patient benefit.

The Link between Periodontal Disease and Asthma: How Do These Two Diseases Affect Each Other?

A growing body of evidence suggests that the effects of poor oral hygiene extend beyond the oral cavity and are associated with a variety of systemic diseases, including asthma. Asthma, which results in symptoms of cough, wheezing, and dyspnoea, and is characterized by airflow limitation with variability and (partial or complete) reversibility, is amongst the most prevalent respiratory diseases with approximately 262 million patients worldwide, and its prevalence and disease burden is on the increase. While asthma can occur at a young age, it can also develop later in life and affects a variety of age groups. Both of these diseases have a chronic course, and various researchers have suggested a link between the two. In this article, we aim to provide a literature review focusing on the association between the two diseases. The results demonstrate that medications (primarily, inhaler medicine), hypoxia induced by asthma, and the breathing behaviour of patients potentially trigger periodontal disease. In contrast, oral periodontopathogenic microorganisms and the inflammatory mediators produced by them may be involved in the onset and/or exacerbation of asthma. Common contributing factors, such as smoking, gastro-oesophageal reflux, and type-2 inflammation, should also be considered when evaluating the relationship between the two diseases.

Dental evaluation is helpful in the differentiation of functional heartburn and gastroesophageal reflux disease

BACKGROUND

Heartburn is identically the key symptom of both, gastroesophageal reflux disease (GERD) and functional heartburn (FHB), making the differential diagnosis resource-intensive. Oral manifestations of GERD can be easily examined; therefore, their exploration might be a cheap, widely available, and useful tool in the differentiation of GERD and FHB.

AIM

To evaluate the prevalence of dental erosions (DE) and periodontal diseases (PD) in patients with heartburn and their association with GERD and FHB.

METHODS

A total of 116 [M/F: 51/65, mean age: 54 (17-80) years] consecutive patients with heartburn were enrolled for detailed esophageal function and orodental examinations.

RESULTS

Dental disorders were detected in 89% (103/116). Patients with PD + DE had significantly more often pathologic reflux (90.0% vs 27.8%; P < 0.05), higher esophagitis scores (1.8 vs 0.9; P < 0.05), and a significantly different mean impedance curve (P = 0.04) than those without any dental diseases. The opposite approach established that patients with GERD had significantly higher prevalence of DE and PD, especially if both were present (28.9% vs 2.0%; P < 0.01), more severe PD (1.5 vs 1.0; P < 0.01), and longer history of heartburn (15 years vs 9 years; P < 0.01) than those with FHB.

CONCLUSION

The dental evaluation of patients with heartburn seems to be useful in the differential diagnosis of GERD and FHB. Among the studied parameters, the co-appearance of DE and PD seems to be the best predictor of GERD, whereas the absence of dental disorders was mostly observed in FHB.

Relationship between gastroesophageal reflux disease and periodontitis

Gastroesophageal reflux disease (GERD) is a condition related to the reflux of gastroduodenal contents into the esophagus, mouth, throat, or lungs. Recent studies have shown that there may be a correlation between GERD and periodontitis, a common oral disease. This review discusses the oral manifestations of GERD and the progress in the understanding of the relationship between GERD and periodontitis.

Gastroesophageal reflux disease and oral symptoms: A two-sample Mendelian randomization study

Background: The association between Gastroesophageal reflux disease (GERD) and oral symptoms has been reported in observational studies, but the causality of GERD to oral symptoms remained unknown. We aimed to assess the causal effect of GERD on five oral symptoms (mouth ulcers, toothache, loose teeth, bleeding gums, and periodontitis) using the two-sample Mendelian randomization (MR) method. Methods: Summary-level statistics for GERD and five oral symptoms were obtained from large-scale genome-wide association studies. Rigorous quality control of genetic instruments was conducted before MR analysis. Several analytical methods, including the inverse-variance weighted (IVW) method, MR-Egger regression, weighted median, maximum likelihood, and robust adjusted profile score (RAPS) were utilized, and the results of IVW were taken as the main results. The MR-Egger intercept test, Cochran's Q test, and leave-one-out test were used as sensitivity analysis for quality control. Results: After Bonferroni, IVW detected a significant effect of GERD on mouth ulcers (OR = 1.008, 95% CI = 1.003-1.013, p = 0.003), loose teeth (OR = 1.009, 95% CI = 1.005-1.012, p = 9.20 × 10^-7), and periodontitis (OR = 1.229, 95% CI = 1.081-1.398, p = 0.002). Consistent patterns of associations were observed across several MR models and sensitivity analysis found little evidence of bias. Nominal significant associations were observed in toothache and bleeding gums (p < 0.05), and heterogeneity was detected. Conclusion: Our MR analyses supported the positive causal effect of GERD on oral symptoms, especially for mouth ulcers, loose teeth, and periodontitis. Our findings might shed light on the mechanism of oral disease and might imply that oral care should be enhanced in patients with GERD.

Risk of Periodontitis in Patients with Gastroesophageal Reflux Disease: A Nationwide Retrospective Cohort Study

Background: Gastroesophageal reflux disease (GERD) is the most common digestive clinical problem worldwide that affects approximately 20% of the adult populations in Western countries. Poor oral hygiene has been reported to be associated with GERD as an atypical clinical complication. However, evidence showing the relationship between GERD and the risk of periodontitis is less clear. The present study aimed to use a retrospective cohort study design to further clarify the association between GERD and the subsequent risk of periodontitis. Methods: The risk of periodontitis in patients with GERD was investigated by analyzing epidemiological data from the Taiwan National Health Insurance Research Database from 2008 to 2018. We selected 20,125 participants with a minimum age of 40 years in the GERD group and 1:1 propensity-matched these with non-GERD individuals by sex, age, and comorbidities. The incidence of periodontitis was determined at the end of 2018. A Cox proportional hazards regression model was used to evaluate the risk of periodontitis in patients with GERD. Results: The overall incidence rate of the periodontitis risk was 1.38-fold higher (30.0 vs. 21.7/1000 person years, adjusted hazard ratio (aHR) = 1.36, 95% confidence interval (CI) = 1.28−1.45) in patients with GERD than in those without GERD. After stratified analyses for sex, age, and comorbidity, patients with GERD had a higher risk of periodontitis for age (aHR = 1.31, 95% CI = 1.20−1.42 for 40−54 years and aHR = 1.42, 95% CI =1.28−1.57 for 55−69 years), sex (aHR = 1.40, 95% CI = 1.28−1.54 for men and aHR = 1.33, 95% CI = 1.23−1.45 for women), and presence (aHR = 1.36, 95% CI = 1.27−1.45) and absence (aHR = 1.40, 95% CI = 1.21−1.62) of comorbidity than those without GERD. Among the GERD cohort, the risk for periodontitis was increased with an increasing number of emergency room visits (≥ 1 vs. <1, aHR = 5.19, 95% CI = 2.16−12.5). Conclusions: Our results revealed that patients with GERD have a higher risk of periodontitis development than those without GERD. Clinicians should pay more attention to identifying and managing periodontitis in patients with GERD.

Multitrait genetic association analysis identifies 50 new risk loci for gastro-oesophageal reflux, seven new loci for Barrett's oesophagus and provides insights into clinical heterogeneity in reflux diagnosis

OBJECTIVE

Gastro-oesophageal reflux disease (GERD) has heterogeneous aetiology primarily attributable to its symptom-based definitions. GERD genome-wide association studies (GWASs) have shown strong genetic overlaps with established risk factors such as obesity and depression. We hypothesised that the shared genetic architecture between GERD and these risk factors can be leveraged to (1) identify new GERD and Barrett's oesophagus (BE) risk loci and (2) explore potentially heterogeneous pathways leading to GERD and oesophageal complications.

DESIGN

We applied multitrait GWAS models combining GERD (78 707 cases; 288 734 controls) and genetically correlated traits including education attainment, depression and body mass index. We also used multitrait analysis to identify BE risk loci. Top hits were replicated in 23andMe (462 753 GERD cases, 24 099 BE cases, 1 484 025 controls). We additionally dissected the GERD loci into obesity-driven and depression-driven subgroups. These subgroups were investigated to determine how they relate to tissue-specific gene expression and to risk of serious oesophageal disease (BE and/or oesophageal adenocarcinoma, EA).

RESULTS

We identified 88 loci associated with GERD, with 59 replicating in 23andMe after multiple testing corrections. Our BE analysis identified seven novel loci. Additionally we showed that only the obesity-driven GERD loci (but not the depression-driven loci) were associated with genes enriched in oesophageal tissues and successfully predicted BE/EA.

CONCLUSION

Our multitrait model identified many novel risk loci for GERD and BE. We present strong evidence for a genetic underpinning of disease heterogeneity in GERD and show that GERD loci associated with depressive symptoms are not strong predictors of BE/EA relative to obesity-driven GERD loci.

Gastroesophageal reflux disease and oral health: A narrative review

Gastroesophageal reflux disease (GERD) is a clinical condition in which stomach contents leak backward into the esophagus. It affects millions of people worldwide and has a detrimental effect on quality of life. Heartburn and acid regurgitation are typical GERD symptoms, while atypical manifestations include noncardiac chest pain, cough and laryngitis. The oral and maxillofacial manifestations of GERD may include dental erosion, xerostomia, mucositis, aphthous like ulcerations, sour taste, burning mouth, hyperesthesia, bruxism, and/or temporomandibular disorder (TMD). This narrative review provides oral health care professionals with an update to medical aspects of GERD, recognition and management of oral and maxillofacial manifestations of the condition and provision of appropriate dental care for this patient population.

Association of preterm birth with medications: machine learning analysis using national health insurance data

PURPOSE

To use machine learning and population data for testing the associations of preterm birth with socioeconomic status, gastroesophageal reflux disease (GERD) and medication history including proton pump inhibitors, sleeping pills and antidepressants.

METHODS

Population-based retrospective cohort data came from Korea National Health Insurance Service claims data for all women who aged 25-40 years and gave births for the first time as singleton pregnancy during 2015-2017 (405,586 women). The dependent variable was preterm birth during 2015-2017 and 65 independent variables were included (demographic/socioeconomic determinants, disease information, medication history, obstetric information). Random forest variable importance (outcome measure) was used for identifying major determinants of preterm birth and testing its associations with socioeconomic status, GERD and medication history including proton pump inhibitors, sleeping pills and antidepressants.

RESULTS

Based on random forest variable importance, major determinants of preterm birth during 2015-2017 were socioeconomic status (645.34), age (556.86), proton pump inhibitors (107.61), GERD for the years 2014, 2012 and 2013 (106.78, 105.87 and 104.96), sleeping pills (97.23), GERD for the years 2010, 2011 and 2009 (95.56, 94.84 and 93.81), and antidepressants (90.13).

CONCLUSION

Preterm birth has strong associations with low socioeconomic status, GERD and medication history such as proton pump inhibitors, sleeping pills and antidepressants. For preventing preterm birth, appropriate medication would be needed alongside preventive measures for GERD and the promotion of socioeconomic status for pregnant women.

Exploring the causal relationship between gastroesophageal reflux and oral lesions: A mendelian randomization study

Background: Clinical observations and retrospective studies have observed that patients with gastroesophageal reflux disease (GERD) have an increased probability of dental erosion, periodontitis and oral mucosal lesions and other common oral lesions. However, whether there is a genetic causal relationship between GERD and the occurrence of oral lesions has not been reported. Methods: In this study, we extracted instrumental variables from the largest published summary statistics of the oral lesion phenotype GWAS in UK Biobank (UKBB) and GERD GWAS. Then, we performed a causal inference analysis between GERD and common oral lesions by mendelian randomization (MR) analysis with the R package "TwoSampleMR". Results: We observed a significant causal relationship between GERD and several common oral lesion phenotypes (painful gums, loose teeth, toothache, and mouth ulcers). GERD showed a positive correlation with the occurrence of these oral lesions. After removing outlier SNPs via the MR-PRESSO package, our conclusions were still robust. Conclusion: Our findings provide the first evidence for a genetic causal effect of GERD on oral lesion pathogenesis. For patients with confirmed GERD, attention should be paid to taking interventions to prevent the occurrence of oral lesions.

Association of Gastroesophageal Reflux Disease with Preterm Birth: Machine Learning Analysis

BACKGROUND

This study used machine learning and population data for testing the associations of preterm birth with gastroesophageal reflux disease (GERD) and periodontitis.

METHODS

Retrospective cohort data came from Korea National Health Insurance Service claims data for all women who aged 25-40 years and gave births for the first time as singleton pregnancy during 2015-2017 (405,586 women). The dependent variable was preterm birth during 2015-2017 and the independent variables were GERD (coded as no vs. yes) for each of the years 2002-2014, periodontitis (coded as no vs. yes) for each of the years 2002-2014, age (year) in 2014, socioeconomic status in 2014 measured by an insurance fee, and region (city) (coded as no vs. yes) in 2014. Random forest variable importance was adopted for finding main predictors of preterm birth and testing its associations with GERD and periodontitis.

RESULTS

Based on random forest variable importance, main predictors of preterm birth during 2015-2017 were socioeconomic status in 2014, age in 2014, GERD for the years 2012, 2014, 2010, 2013, 2007 and 2009, region (city) in 2014 and GERD for the year 2006. The importance rankings of periodontitis were relatively low.

CONCLUSION

Preterm birth has a stronger association with GERD than with periodontitis. For the prevention of preterm birth, preventive measures for GERD would be essential together with the improvement of socioeconomic status for pregnant women. Especially, it would be vital to promote active counseling for general GERD symptoms (neglected by pregnant women).

Reflex Gastroesophageal Disorders and Functional Dyspepsia: Potential Confounding Variables for the Progression of Chronic Periodontitis: A Clinical Study

Aim:

To probe into the possible connection between gastroesophageal reflux disorders (GERDs) and functionally occurring dyspepsia as a factor raising the risk of chronic periodontitis.

Materials and Methods:

A cross-sectional study was carried out on 40 patients with chronic periodontitis with age group between 40–60 years. The test group included 20 people diagnosed with gastroesophageal reflux disease (GERD), according to the Montreal Definition and Classification agreement, and chronic periodontitis. Symptomatic diagnoses were done to confirm functional dyspepsia. The control group comprised 20 systematically healthy people suffering from chronic periodontitis. Indices measured included flow-rate of saliva, repetitive saliva swallowing test for swallowing function, papillary marginal attachment index of gingiva, oral hygiene index-simplified and decayed, missing, filled teeth index. Data was analyzed using SPSS version 22 (IBM Inc. Chicago, USA). Descriptive statistics, such as mean and standard deviation (SD) for continuous variables and frequency and percentage for categorical variables were determined. T test was performed for intergroup comparison and Pearson correlation test was done for evaluating correlation between various parameters. P ≤ 0.05 considered as significant.

Results:

Statistically significant differences were observed between the test and control groups with regard to all the clinical parameters of interest. Pearson's correlation test revealed a strong negative correlation between salivary flow rate and OHI-S and DMFT scores. The RSST swallow function values demonstrated a moderate negative correlation with OHI-S scores, while OHI-I scores and DMFT scores were observed to be strongly correlated in a positive direction. A statistically significant difference was present in the probing depth and CAL levels between both the groups with higher levels in test group.

Conclusion:

GERD was linked to incremental incidences of chronic periodontitis and was established as an independent risk-raising factor.

Laryngopharyngeal reflux, gastroesophageal reflux and dental disorders: A systematic review

OBJECTIVES

To investigate the role of gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) in the development of dental disorders.

METHODS

The first outcome was review of the role of reflux in the development of dental disorders in adults. The second outcome was review of the potential pathophysiological mechanisms underlying the association between reflux and dental disorders. Three investigators screened publications for eligibility and exclusion based on predetermined criteria through a literature search conducted on PubMed, Cochrane Library, and Scopus according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

From 386 publications, 24 studies were kept for analysis. Objective approaches were used in 16 studies to confirm GERD diagnosis. Pharyngeal reflux episodes (LPR) were considered in 2 studies. No study considered nonacid reflux. The study results supported a higher prevalence of dental erosion and caries in reflux patients compared with healthy individuals. Patients with dental erosion have a higher prevalence of reflux than controls. The pathophysiological mechanisms would involve changes in the saliva physiology. No study investigated the microbiota modifications related to reflux although the findings are supporting the critical role of microbiota change in the development of dental disorders. There is an important heterogeneity between studies about diagnostic methods and clinical outcome evaluation.

CONCLUSION

The involvement of reflux in the development of dental disorders is not formally demonstrated and requires future investigations considering pharyngeal acid and nonacid reflux episodes and in particular their potential impact on oral microbiota.

Determinants of Spontaneous Preterm Labor and Birth Including Gastroesophageal Reflux Disease and Periodontitis

BACKGROUND

Periodontitis is reported to be associated with preterm birth (spontaneous preterm labor and birth). Gastroesophageal reflux disease (GERD) is common during pregnancy and is expected to be related to periodontitis. However, little research has been done on the association among preterm birth, GERD and periodontitis. This study uses popular machine learning methods for analyzing preterm birth, GERD and periodontitis.

METHODS

Data came from Anam Hospital in Seoul, Korea, with 731 obstetric patients during January 5, 1995 - August 28, 2018. Six machine learning methods were applied and compared for the prediction of preterm birth. Variable importance, the effect of a variable on model performance, was used for identifying major determinants of preterm birth.

RESULTS

In terms of accuracy, the random forest (0.8681) was similar with logistic regression (0.8736). Based on variable importance from the random forest, major determinants of preterm birth are delivery and pregestational body mass indexes (BMI) (0.1426 and 0.1215), age (0.1211), parity (0.0868), predelivery systolic and diastolic blood pressure (0.0809 and 0.0763), twin (0.0476), education (0.0332) as well as infant sex (0.0331), prior preterm birth (0.0290), progesterone medication history (0.0279), upper gastrointestinal tract symptom (0.0274), GERD (0.0242), Helicobacter pylori (0.0151), region (0.0139), calcium-channel-blocker medication history (0.0135) and gestational diabetes mellitus (0.0130). Periodontitis ranked 22nd (0.0084).

CONCLUSION

GERD is more important than periodontitis for predicting and preventing preterm birth. For preventing preterm birth, preventive measures for hypertension, GERD and diabetes mellitus would be needed alongside the promotion of effective BMI management and appropriate progesterone and calcium-channel-blocker medications.

Clinical periodontal conditions in individuals after bariatric surgery: a systematic review and meta-analysis

The aim of the present study was to perform a systematic review and meta-analysis to assess the influence of bariatric surgery on the clinical periodontal conditions in patients with obesity. This review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and registered at the International Prospective Registry of Systematic Reviews (CRD42018099313). A search was conducted by 2 investigators in the PubMed/MEDLINE, Web of Science, and Cochrane Library databases for relevant articles published up to May 2018. The inclusion criteria were randomized controlled trials, prospective and retrospective studies, observational studies, longitudinal studies, and cohort studies with at least 3 months of follow-up. No language restrictions were imposed. The exclusion criteria were studies that did not evaluate or report the periodontal measurements, cross-sectional studies (without follow-up after surgery), studies that performed periodontal treatment, and those with insufficient periodontal data. The meta-analysis was based on the Mantel-Haenszel method and inverse variance. The quantitative analysis revealed no statistically significant differences with regard to bleeding on probing (P = .9; mean deviation: -.70; confidence interval = -11.43 to 10.04) or probing pocket depth (P = .41; mean deviation: -.46; confidence interval = -1.55 to .63) before and after intervention. Clinical attachment loss showed a statistically significant difference (P = .0002; mean deviation: .18; confidence interval = .07-.30). It can be concluded that bariatric surgery does not influence bleeding on probing or probing pocket depth, but leads to a worsening of clinical attachment loss.

Acidification induces OGR1/Ca2+/calpain signaling in gingival fibroblasts

Gingivitis, the mildest form of periodontitis, is generally considered a consequence of prolonged exposure of the gingiva to periodontal pathogens. On the other hand, several epidemiologic reports have suggested that other etiologic factors such as oral acidification may also increase the susceptibility of the periodontium to destruction. However, the pathologic mechanism underlying the effects of oral acidification on the gingiva is still largely unknown. In this study, we analyzed molecular pathways mediating the influence of the acidic environment on human gingival fibroblasts (HGFs). Acidic extracellular pH caused biphasic increase of intracellular Ca²⁺ level ([Ca²⁺]_i) through activation of ovarian cancer G protein-coupled receptor 1, phospholipase C, and Ca²⁺ release from the endoplasmic reticulum, but not through voltage-gated Ca²⁺ channels or extracellular Ca²⁺ influx via transient receptor potential cation channel subfamily V member 1. The acidic environment was also transiently cytotoxic for HGFs; however, the activation of pro-apoptotic proteins poly (ADP-ribose) polymerase-1 and BAX was not observed. Furthermore, we found that intracellular matrix metalloproteinase 1 was consistently upregulated in HGFs grown in regular medium, but significantly reduced in the acidic medium, which depended on [Ca²⁺]_i increase, lysosomal pH homeostasis, and Ca²⁺-dependent protease calpain. Considering that HGFs, essential for oral wound healing, in the in vitro culture system are placed in wound repair-like conditions, our findings provide important insights into molecular mechanisms underlying HGF functional impairment and chronic damage to the gingiva caused by the acidic intraoral environment.

Oral soft tissue disorders are associated with gastroesophageal reflux disease: retrospective study

Background

Dental erosion (DE), one of oral hard tissue diseases, is one of the extraoesophageal symptoms defined as the Montreal Definition and Classification of gastroesophageal reflux disease (GERD). However, no study evaluated the relationship between GERD and oral soft tissues. We hypothesized that oral soft tissue disorders (OSTDs) would be related to GERD. The study aimed to investigate the association OSTDs and GERD.

Methods

GERD patients (105 cases), older and younger controls (25 cases each) were retrospectively examined for oral symptoms, salivary flow volume (Saxon test), swallowing function (repetitive saliva swallowing test [RSST]), teeth (decayed, missing, and filled [DMF] indices), and soft tissues (as evaluation of OSTDs, gingivitis; papillary, marginal, and attached [PMA] gingival indexes, simplified oral hygiene indices [OHI-S], and inflammatory oral mucosal regions). Clinical histories, which included body mass index [BMI], the existence of alcohol and tobacco use, and bruxism, were also investigated. A P value of <0.05 was defined as statistically significant.

Results

GERD patients, older and younger controls participated and aged 66.4 ± 13.0, 68.3 ± 8.2 and 28.7 ± 2.6 years old, respectively. The most common oral symptom in the GERD patients was oral dryness. Salivary flow volume and swallowing function in the GERD patients were significantly lower than in either of the controls (all P < 0.05). Inflammatory oral mucosal regions were found only in the GERD patients. The DMF indices, as a measure of dental caries, in the GERD patients were higher than in the younger controls (P < 0.001), but lower than in the older controls (P = 0.033). The PMA gingival indexes, as a measurement for gingival inflammation, and OHI-S, as a measure for oral hygiene, in the GERD patients were significantly higher than in either of the controls (all P < 0.05). Though no significant differences in BMI, the existence of alcohol and tobacco use were found, bruxism, as an exacerbation factor of periodontal disease, in the GERD patients was significantly more frequent than in either control group (P = 0.041).

Conclusions

OSTDs were associated with GERD, which was similar to the association between DE and GERD.

Interplay of Toll-Like Receptor 9, Myeloid Cells, and Deubiquitinase A20 in Periodontal Inflammation

Toll-like receptor 9 (TLR9)-deficient (TLR9^-/-) mice are resistant to periodontitis, a disease characterized by a dysbiotic microbiota and deregulated immune response and resulting in tooth loss and various systemic conditions. However, the mechanisms and biological pathways by which TLR9 instigates periodontal inflammation are yet to be identified. In a ligature-induced model of periodontitis, we demonstrate that TLR9^-/- mice exhibited significantly less alveolar bone loss than their wild-type (WT) counterparts. Consistent with the disease phenotype, gingival tissues showed significantly more inflammatory cell infiltration in the WT ligated but not in the TLR9^-/- ligated mice compared to the unligated controls. The peritoneal infection model using Porphyromonas gingivalis, a keystone pathogen for periodontitis, revealed reduced neutrophils in TLR9^-/- mice on day 1 postinfection compared to the levels in WT mice. Transcriptomics analyses showed increased expression of A20 (tumor necrosis factor alpha [TNF-α]-induced protein 3 [TNFAIP3]), an inhibitor of the NF-κB pathway and a negative regulator of TLR signaling, in ligated TLR9^-/- mouse gingival tissues compared to its expression in the WT. Ex vivo, TLR9^-/- bone marrow-derived macrophages produced more A20 than WT cells following P. gingivalis challenge. Clinically, A20 was modestly upregulated in human gingival tissue specimens from chronic periodontitis patients, further confirming the biological relevance of A20 in periodontal inflammation. We conclude that TLR9 modulates periodontal disease progression at both the cellular and molecular level and identify A20 as a novel downstream signaling molecule in the course of periodontal inflammation. Understanding the regulation of the TLR9 signaling pathway and the involvement of A20 as a limiting factor of inflammation will uncover alternative therapeutic targets to treat periodontitis and other chronic inflammatory diseases.

The Association of Gum Bleeding with Respiratory Health in a Population Based Study from Northern Europe

BACKGROUND

There is little knowledge about how oral and respiratory health is interrelated even though the mucosa of the oral cavity and airways constitutes a continuum and the exposures to these are partly similar.

AIMS

To investigate whether gum bleeding is related to asthma, respiratory symptoms and self-reported COPD.

METHODS

A postal questionnaire including questions about respiratory and oral health was sent to general population samples in seven Northern European centres. In 13,409 responders, gum bleeding when brushing teeth was reported always/often by 4% and sometimes by 20%. Logistic regressions accounted for age, smoking, educational level, centre and gender. Effects of BMI, cardio-metabolic diseases, early life factors, gastro-oesophageal reflux, dental hygiene, nasal congestion, and asthma medication were addressed.

RESULTS

Gum bleeding always/often was significantly associated with ≥ 3 asthma symptoms (OR 2.58, 95% CI 2.10-3.18), asthma (1.62 [1.23-2.14]) and self-reported COPD (2.02 [1.28-3.18]). There was a dose-response relationship between respiratory outcomes and gum bleeding frequency (≥ 3 symptoms: gum bleeding sometimes 1.42 [1.25-1.60], often/always 2.58 [2.10-3.18]), and there was no heterogeneity between centres (p(heterogeneity) = 0.49). None of the investigated risk factors explained the associations. The observed associations were significantly stronger among current smokers (p(interaction) = 0.004).

CONCLUSIONS

A consistent link between gum bleeding and obstructive airways disease was observed, not explained by common risk factors or metabolic factors. We speculate that oral pathogens might have unfavourable impact on the airways, and that the direct continuity of the mucosa of the oral cavity and the airways reflects a pathway that might provide novel opportunities for interventions.

Erosive esophageal reflux vs. non erosive esophageal reflux: oral findings in 71 patients

BACKGROUND

The purpose of this clinical study was to assess the prevalence of acidic oral mucosal lesions and periodontal conditions in patients suffering from erosive esophageal reflux disease (ERD) compared with non erosive esophageal reflux disease (NERD) patients, both treated with long term proton pump inhibitors (PPI).

METHODS

Seventy-one patients with diagnosed GERD were studied: i.e. 29 ERD and 42 NERD patients. Thorough visual examination of the oral mucosa and a periodontal evaluation was performed. The primary outcome was defined as a statistically significant difference, between the two groups, in the presence of acidic lesions of the oral mucosa and specific periodontal parameters.

RESULTS

This study failed to demonstrate statistically significant differences between ERD and NERD patients with respect to the prevalence of oral mucosal lesions. However, significantly more ERD patients suffered from severe periodontitis (CAL ≥ 5 mm) as compared to NERD patients. Accordingly, it may be assumed that PPI-use had no adverse effects on the prevalence of acidic oral mucosal lesions and on periodontal destruction.

CONCLUSIONS

Within the limitations of this study it may be concluded that ERD and NERD patients need separate evaluation with respect to periodontal destruction. Moreover, long term PPI medication had no adverse clinical impact on acidic oral mucosal lesions and periodontal destruction. Further studies are necessary to elucidate the role of reflux in the periodontal destruction of ERD individuals.