Longitudinal analysis of parotid and submandibular salivary flow rates in healthy, different-aged adults.

BACKGROUND Early studies suggested that salivary gland dysfunction was a normal sequela of aging. Recent research on healthy, different-aged adults has led to a revision of these former conclusions. Parotid gland function appears to be age-stable, yet there is no consensus on submandibular/sublingual output. To date, there have only been two longitudinal studies utilizing healthy individuals examining parotid function, and no published longitudinal studies on submandibular/sublingual output. The purpose of this study was to examine unstimulated and stimulated major salivary gland flow rates in unmedicated, essentially healthy subjects, over a 3-year period. METHODS Thirty-seven males and females, aged 26-90 years of age, were examined twice over a 3-year period at the Clinical Center of the National Institutes of Health. All were healthy, community-dwelling adults, without systemic diseases, and not taking any medications. Unstimulated and 2% citrate-stimulated parotid and submandibular/sublingual salivary gland flow rates were assessed at both visits, and changes over time were evaluated according to the subject's age at initial visit. RESULTS There were no significant flow rate differences over a 3-year time period for unstimulated and stimulated parotid and submandibular/sublingual flow rates. CONCLUSIONS Major salivary gland output is aged-stable in healthy persons over a 3-year period. The data from this study suggest that salivary gland dysfunction in an older person should not be considered a normal process of aging.