A Pilot Study of Perceived Mouth Dryness, Perceived Swallowing Effort, and Saliva Substitute Effects in Healthy Adults Across the Age Range

Xerostomia, or perceived mouth dryness, increases with advancing age, but its influence on swallowing effort is unknown. This study: (1) quantified relationships among age, perceived sense of swallowing effort, and ratings of perceived mouth dryness, and (2) examined changes in swallowing effort following application of a gel-based saliva substitute in healthy participants. This was a cross-sectional observational study and data were collected from attendees of a community healthy aging fair. Forty-two healthy participants (mean age = 65 years; 20 female) were enrolled. Each participant rated perceived effort with swallowing and perceived mouth dryness on a 10-cm horizontal, undifferentiated line. After participants applied a gel-based saliva substitute (Biotene^® Oral Balance) to their tongue and oral mucosa, they rated perceived effort with swallowing again. Age was associated with greater perceived mouth dryness (r = 0.37, p < 0.03) but not with perceived swallowing effort (r = 0.16, p = 0.32). Perceived mouth dryness was associated with greater perceived swallowing effort (r = 0.62, p < 0.001). Perceived swallowing effort declined following application of the salivary substitute (mean difference = 9.39 mm, p < 0.002). Age was found to be a significant predictor of perceived mouth dryness (p < .02); and perceived mouth dryness was found to significantly predict perceived swallow effort (p < .001). Perceived mouth dryness increased with advancing age, but perceived swallowing effort did not. Regardless of age, participants with higher levels of perceived mouth dryness also reported more perceived effort with swallowing suggesting a role for adequate oral lubrication in this perception. Even in healthy participants, use of a gel-based saliva substitute lowered perceived swallowing effort.