Flow Rates of Resting Whole and Stimulated Parotid Saliva in Relation to Age and Gender

Abstract

Dry mouth is a common feature in the elderly, but it is not clear what proportion of incidences are related to functional disturbances and whether age per se and gender play a role. The aim of this study was to determine the effects of age and gender on salivary flow rates. The effect of age on unstimulated (resting) whole and stimulated parotid saliva flow rates was determined in 116 unmedicated, healthy individuals. The subjects were divided into four age groups: 20-39 years (group A), 40-59 years (group B), 60-79 years (group C), and 80 years and over (group D). A significant decrease in the secretion rates of unstimulated whole saliva in relation to age was observed in the study population (p < 0.001). However, the flow rates of stimulated parotid saliva were not significantly different in the four age groups. Females had significantly lower mean flow rates than males for both unstimulated (resting) whole saliva (p < 0.005) and stimulated parotid saliva (p < 0.05). In the study as a whole, significant negative correlations were found between either the DMF index (decayed, missing, and filled teeth) or the DMFS index (decayed, missing, and filled tooth surfaces) and the flow rates of unstimulated whole saliva (p < 0.02), but no relationship to stimulated parotid saliva flow rates was apparent. The results suggest that elderly subjects have no impairment in their ability to respond to sialogogues but that resting saliva rates are significantly lower than in younger individuals and may contribute to the increase in oral mucosal diseases seen in the elderly.