Investigating the relationship between hyposalivation and mucosal wetness

Background: Mucosal wetness (MW) reflects the layer of residual saliva that covers the oral mucosal surfaces. Objectives: The aim of this study was to determine MW at different oral mucosa sites and to investigate the relationship between MW, unstimulated whole salivary flow rates (UWS) and Clinical Oral Dryness Score (CODS). Method: A total of 100 dry mouth patients and 50 healthy subjects participated in the study. MW was sampled with filter paper strips at four sites inside the mouth; anterior hard palate (AHP), buccal mucosa (BUC), anterior tongue (AT), lower lip (LL) and measured with a micro-moisture meter. Reproducibility was assessed by repeated sampling and diurnal variation was examined. Results: Mucosal wetness in healthy subjects differed according to site and means +/- SD were; AHP (11 +/- 11.7 mu m), BUC (32 +/- 14.8 mu m), AT (65 +/- 17.2 mu m), and LL (25 +/- 13.5 mu m). Dry mouth patients with reduced UWS showed increased CODS. MW at all four sites was significantly reduced (P < 0.05) in dry mouth patients compared with the healthy subjects. Reproducibility of MW measurement using the intra-class correlation coefficient showed agreement at different visits within subject. MW of the AT showed a positive correlation with UWS (P < 0.05). Conclusion: Mucosal wetness is a reliable measure of oral dryness and had a positive correlation with UWS.