Whole saliva and residual mucosal saliva in patients with burning mouth syndrome: a case-control study

Abstract

Objectives Burning mouth syndrome (BMS) is a chronic pain condition. Xerostomia is a common complaint among patients with BMS. However, previous studies have reported inconsistent findings regarding salivary flow rate reduction among these patients. The aim of this study was to examine unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) flow rates, degree of mucosal hydration, and xerostomia in female patients with BMS compared with controls. Study Design The study included female patients diagnosed with BMS (ICD-10 code K14.6) at a university oral medicine clinic. Controls were similarly aged women without BMS. Collection of salivary samples and other data took place during a 1-hour session between 9:00 a.m. and 12:00 noon. UWS was collected under resting conditions by passive drooling into a plastic tube for 10 minutes; to assess mucosal hydration, residual mucosal saliva (RMS) was collected by using filter paper strips, from 4 mucosal sites—anterior hard palate, buccal mucosa, anterior tongue, and lower lip. The strips were then placed in a microcentrifuge tube and weighed. SWS was collected while the patient chewed on gum base for 5 minutes. Low UWS was defined as 0.1 mL/min or less and low SWS as 0.7 mL/min or less. Participants completed the Short Form of the Xerostomia Inventory (SXI-D). We used the χ2 test to assess the association between UWS, SWS, and BMS and t tests to assess the differences in residual mucosal saliva (RMS) levels. Results Fifty-six women (27 cases and 29 controls) participated in this study. Mean age was 61 years for cases and 58 for controls (n.s.). Most participants in each group were postmenopausal; 66% of cases versus 38% of controls had low UWS (P = .03; and 48% of cases versus 34% of controls had low SWS (P =.06). Compared with controls, BMS cases had lower mean levels of tongue RMS (0.007 g vs 0.01 g; P = .03); 55% of the cases versus 7% of controls reported xerostomia (P Conclusions Patients with BMS had statistically significant reductions in UWS and tongue RMS and a higher prevalence of xerostomia. Low hydration of the tongue should be further investigated as a possible trigger of xerostomia sensation.