Influence of Inflammation, Gut Microbiota, and Stress on Cognition and Oral Health Therapies

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.