Aspiration pneumonia is an inflammation of the lungs and bronchial tubes caused by inhalation of a significant amount of foreign material, such as food or secretions from the oral cavity and gastrointestinal tract. Although it is less prevalent than other types of pneumonia, aspiration pneumonia has a high mortality rate, particularly among hospitalized and nursing home patients. Risk factors for aspiration pneumonia include advanced age, debilitation, feeding by tube, and chronic diseases. Oral health factors that increase risk include difficulty swallowing, uncontrolled plaque, periodontal disease, and caries. The more common type of pneumonia is community-acquired pneumonia (CAP), which affects between 1 and 2 million persons in the US each year. Aspiration of oral bacteria may play a role in the development of CAP as well.

The aim of this study was to determine the relationship between oral status and mortality rate from pneumonia in elderly individuals. Evaluations were conducted using questionnaires, physical examinations, and laboratory blood tests. From 1998 through 2002, 108 of the study persons died, and of those, 22 deaths were due to pneumonia. Of those 22 deaths, the adjusted mortality was nearly four times higher among persons with 10 or more teeth having a probing depth exceeding 4 mm compared to those without periodontal pockets. This statistically significant finding led the authors to conclude that among the elderly, an increase in the number of teeth with periodontal pockets may be associated with increased mortality from pneumonia.