[Research progress in the bidirectional relationship between oral infectious diseases and mental health issues]

Infectious oral diseases represent the most prevalent categories of oral conditions, including dental caries, periodontitis, periapical lesions, and pericoronitis. Their bidirectional relationship with mental health has emerged as a critical interdisciplinary research frontier. This paper integrates epidemiological findings and molecular mechanism evidence to analyze the significant comorbidity and correlation characteristics between infectious oral diseases such as caries and periodontitis, and psychological disorders including depression and anxiety. Oral diseases not only directly impair mental well-being through pain, functional impairment, and social anxiety, but also induce systemic inflammatory responses that disrupt the blood-brain barrier, activate microglia, and alter neurotransmitter metabolism, thereby contributing to functional dysregulation within emotional regulatory centers. The dysbiosis of the oral microbiota caused by infectious oral diseases plays a central role in the vicious cycle of "oral infection-mental health disorders" through the"oral-gut-brain axis", inflammation-mediated neuroimmune cascades, and hypothalamic-pituitary-adrenal axis dysregulation. Meanwhile, mental disorders exacerbate oral microbial imbalance and tissue destruction through poor oral hygiene behaviors, xerostomia induced by psychotropic medications, and stress-related neuroendocrine alterations. This paper advocates for synergistically integrate oral clinical interventions with mental health improvement strategies, and for the development of microbiome-targeted precision modulation approaches. It further proposes an integrated health management paradigm that bridges dentistry and psychiatry, providing both theoretical foundations and practical pathways to transcend traditional disciplinary boundaries and achieve holistic oral-mental co-management.