65 Differences in perceived intra-oral dryness DISCUSSION The results of this study, in which we explored the RODI questionnaire in specific subgroups of dry-mouth patient groups, show that the regions of perceived intra-oral dryness differed between the groups. Controls and Low Med patients had the lowest RODI scores and experienced less intra-oral dryness than the other groups of patients. On the other hand, SS and SS + High Med patients had the highest RODI scores, meaning that they experienced more intra-oral dryness. The RODI scores of our sample revealed that the posterior palate was experienced as the most dry, while the inside cheeks were experienced as the least dry. This result is consistent with the findings of a previous study in which patients also indicated that the posterior palate was the most dry [13]. Several factors make the palate more susceptible to oral dryness than other intra-oral locations: gravity, evaporation, and the paucity of palatal glands [23–25]. For the region that was experienced as the least dry, perceived dryness did not differ significantly between the inside cheeks and the floor of the mouth (Table 3). Both regions include orifices of the major salivary glands [23]. Because of their proximity to the orifices of the salivary glands, the saliva film in these regions is probably more moisturizing than the saliva film on the palate [24, 26–28]. For this reason, all patients experienced the inside cheeks and the floor of the mouth as less dry. This finding is comparable with that in the previous study, which found that patients experienced the floor of the mouth as the least dry [13]. Our results showed that the controls and SS patients experienced the posterior palate as the driest. Notably, they show that SS patients had significantly higher RODI scores (median score 4.00) for the posterior palate than controls did (median score 3.00). This can be explained by the fact that except for the palatal salivary flow rate [29, 30], the UWS flow rate in SS patients is lower [20, 29–34]. Indeed, the number of patients with xerostomia was higher in SS patients [29, 30, 32]. A plausible explanation is that the subjective feeling of xerostomia is strongly related to the UWS flow. In controls—who had sufficient UWS—the palatal glands contributed little to the dry-mouth feeling [28]. This suggestion is further supported by Wang and co-workers, who did not find a significant correlation between summated XI scores and minor salivary-gland flow rates [35]. This is consistent with the fact that under healthy conditions, the saliva secreted by theminor salivary glands’ accounts for less than 10% of whole saliva [36]. Additionally, SS patients have other saliva-related characteristics that induce dry mouth: an altered sialochemical composition, such as higher 3
RkJQdWJsaXNoZXIy MTk4NDMw