“…To date, periodontal disease has been reported as a risk factor for diabetes mellitus (DM), cardio-and cerebrovascular disease, aspiration pneumonia, premature and low birth weight infants, bacterial endocarditis, glomerulonephritis, arthritis, and palmoplantar pustulosis [1][2][3][4][5]. The following three pathways are assumed to be the mechanism of the systemic spread of periodontal disease: direct action of bacterial body and toxin of periodontal disease-related bacteria at the local periodontal site that spread to target organs through the hematogenous route or respiratory tract [4]; the action of inflammation-inducing substances such as cytokines, which are produced by the inflammatory response within periodontal tissue or immune response that spread hematogenously to the target organs [5]; and a pathway that results in intracerebral spread through the nervous system [6,7]. There are various data on intravascular infiltration of periodontal disease-related bacteria and its spread to target organs thus far, but its mechanism of affecting diseases is not fully understood.…”