The human oral cavity hosts a complex and dynamic microbial ecosystem, second only to the gut in microbial diversity. While the gut-brain axis has been extensively studied, the potential influence of the oral microbiome on mental health remains underexplored. Evidence has emerged suggesting a significant link between the oral microbiome and mental health. Recent studies indicate that oral microbial dysbiosis may contribute to neuroinflammatory processes, thereby affecting mental health outcomes. This review explores the current findings on how dysbiosis in the oral microbiota may influence neuropsychiatric outcomes through systemic inflammation, microbial translocation, and neural pathways. Understanding the oral-brain axis could pave the way for novel diagnostic and therapeutic strategies in mental health care.