Elderly subjects (N 430) from four convenience populations that represented different levels of medical health--independent living (Veterans Affairs and non-Veterans Affairs), nursing home, and hospitalized acute care--were given dental examinations. The independent living groups had significantly higher numbers of functional units (opposing natural or prosthetic tooth pairs) and of contiguous functional units compared with the nursing home and hospitalized groups. There was a shift from functional units that consisted of natural teeth to functional units that consisted of prosthetic teeth in the nursing home and hospitalized groups. Numbers of functional units were negatively correlated to plaque index, papillary bleeding scores, and minor salivary gland output. This study suggests a strong relationship between functional integrity of the dentition and general health.