Oral Health and Pneumonia

The oral cavity can serve as a source of infection of the lungs. Aspiration of bacteria from the oral cavity into the lower airway is possible since the surfaces of the oral cavity are contiguous with those of the trachea and lower airway. Aspirated bacteria, either normal inhabitants of the oral cavity that serve as opportunistic pathogens in susceptible patients or exogenous pathogens that are not normal members of the oral flora and that transiently colonize the oral cavity, can cause lung infections. In addition, biological mediators, such as cytokines and hydrolytic enzymes, released from the periodontium as the result of periodontal inflammation are aspirated into the airway and may stimulate inflammation and increase susceptibility to infection. This chapter reviews recent evidence implicating the oral microflora and oral inflammation in the etiology of pneumonia.