Periodontal diseases are inflammatory diseases caused by oral pathogens around the periodontal supporting tissues, leading to systemic and chronic inflammatory conditions. The continuous chronic systemic inflammation may be a trigger of neuroinflammation, which is the prominent feature of a variety of neurological disorders. It implies that there may be a causal link between periodontal diseases and neurological disorders. This article presents epidemiological and biological evidences that periodontal diseases can induce or exacerbate neurological disorders, including Alzheimer’s disease, Parkinson’s disease, multiple sclerosis and major depressive disorder, and analyzes the possible mechanisms. The importance of maintaining oral health as well as preventing and treating periodontal diseases are emphasized. At the same time, this may provide novel approaches to study the relationship between periodontal diseases and neurological disorders in the prevention and treatment strategies of neurological disorders. CLICK TO REVIEW