Systemic diseases caused by oral infection

Recently, it has been recognized that oral infection, especially periodonti tis, may affect the course and pathogenesis of a number of systemic disease s, such as cardiovascular disease, bacterial pneumonia, diabetes mellitus, and low birth weight. The purpose of this review is to evaluate the current statics of oral infections, especially periodontitis, as a causal factor f or systemic diseases. Three mechanisms or pathways linking oral infections to secondary systemic effects have been proposed (i) metastatic spread of i nfection from the oral cavity as a result of transient bacteremia, (ii) met astatic injury from the effects of circulating oral microbial toxins, and ( iii) metastatic inflammation caused by immunological injury induced by oral microorganisms. Periodontitis as a major oral infection may affect the hos t's susceptibility to systemic disease in three ways: by shared risk factor s; subgingival biofilms acting as reservoirs of gram-negative bacteria; and the periodontium acting as a reservoir of inflammatory mediators: Proposed evidence and mechanisms of the above odontogenic systemic diseases are giv en.