Oral Health Research

Poor oral health can impact an individual's ability to eat and has been associated with an increased risk of non-communicable diseases. While the benefits of nitrate consumption on oral health were first proposed more than 20 years ago, no systematic review has been published examining effects of dietary nitrate on oral health. This systematic review investigated the effects of dietary nitrate on markers of oral health

Sex is an often overlooked, yet compulsory, biological variable when performing biomedical research. Periodontitis is a common yet progressively debilitating chronic inflammatory disorder affecting the tissues supporting teeth that ultimately leads to tooth loss if left untreated. The incidence of periodontitis is sex biased, with increased prevalence in males compared with females but with unknown etiology. We performed a sex-specific meta-analysis using publicly available oral microbiome data from different sampling sites of patients with periodontitis and periodontally healthy controls; sex balance was established for each periodontal health condition. Our results show sex-based diversity in oral biofilms of individuals with periodontitis but not in their saliva, with increased abundance of several periodontal pathogens in subgingival plaques from females compared with males. We devised a quantitative measure, uniquely defined as the Microsexome Index (MSI), which indicates that sexual dimorphism in subgingival bacterial composition is a distinct feature of reduced microbial diversity during periodontitis but not under healthy conditions. In addition, we found that smoking exacerbates microsexome diversity in supragingival biofilms, particularly during periodontitis. Taken together, we provide insights regarding sex-based diversity in periodontitis, a disease with multiorgan associations, and provide the rationale for further mechanistic, diagnostic, and therapeutic studies.

[BACKGROUND] Prolonged or repeated psychological stress triggers dental and orthodontic diseases via inflammatory pathways and oxidative stress. This review aims to elucidate the role of inflammation, gut microbiota, stress, and cognition, exploring their impact on the development of therapeutics to enhance oral health. [OBJECTIVE] The primary aim pertinent to this systematic review is to elucidate the significant implications of cognition and stress in dental and orthodontic health. Specifically, the review aims to (1) investigate the association between emotional stress and the incidence or progression of periodontal disease; (2) explore the impact of physiological and emotional stress on cellular and molecular inflammatory responses in orthodontics; (3) examine the influence of gut-mediated psychophysiological factors on emotional changes in mental health and cognition with a focus on periodontics and orthodontics; and (4) investigate the potential of gut microbiota alterations to influence oral and cognitive/mental health, including the impact of probiotic supplementation and dietary interventions. [METHODS] A systematic review was conducted without comprehensive meta-analysis, focusing on literature from 1960 to 2024. Databases searched included PubMed, Embase, ReleMed, National Library of Medicine (NLM), Scopus, and Google Scholar. Keywords used were "cognition," "emotional stress," "gut microbiota," "orthodontics," "prosthetics," "pathophysiology," and "mental health." Studies were selected based on relevance, publication date, access to full texts, and adherence to PRISMA guidelines. The review integrated findings on the impact of emotional stress on periodontal disease and orthodontic health through pathophysiological implications. [RESULTS] Age-related neurodegeneration causes Alzheimer's disease and severe dementia that subsequently promotes poor oral health. The review identified a complex interplay between emotional stress and periodontal disease. While a direct association remains to be conclusively proven, several studies highlight the influence of stress on the severity and incidence of periodontal disease through inflammatory and immunological pathways. Stress manifests in various ways, such as increased masticatory muscle tone, changes in eating behavior, and the initiation of bruxism, all of which can affect dental health. Physiological stress induces an inflammatory response to orthodontic tooth movement, impacting orthodontic treatment outcomes. Furthermore, the review elucidates the role of gut-mediated psychophysiological factors in emotional changes, influencing periodontal and orthodontic health. Emerging evidence suggests that gut microbiota alterations can significantly impact oral and cognitive health through systemic inflammation and neuroimmune mechanisms. [CONCLUSION] This review highlights the significant impact of physiological and emotional stress on periodontal and orthodontic health. Detailed exploration of cellular and molecular inflammatory responses provides insights into the pathophysiology of orthodontic diseases and their impact on oral health. Gut-brain-oral axis has significance in oral health, exploring how alterations in gut microbiota influence oral and cognitive health. It is essential to investigate the impact of probiotic supplementation and dietary modifications on gut microbiota composition, systemic inflammation, and their influence on both cognitive and oral health. Clinical trials assessing the effectiveness of anti-inflammatory treatments in reducing periodontal disease and cognitive decline could offer valuable insights. Integrating advanced microbiome analysis techniques and neuroimaging can help clarify the mechanisms linking gut health, systemic inflammation, and cognitive function. Exploring specific gut microbiota strains that regulate systemic inflammation and cognitive function may lead to targeted probiotic therapies, potentially alleviating neuroinflammation and enhancing cognitive performance. Additionally, understanding the role of oral probiotics in periodontal health and their effects on gut microbiota and systemic inflammation could contribute to the development of innovative treatment approaches. This knowledge can aid molecular biologists, dentists, and researchers in managing oral and gut health more effectively.