Development and Proposal of a Novel Scoring System to Classify Dry Mouth Severity

Dry mouth is a common complaint with unmet treatment needs, reflected by the fact that more than 500 trials are registered on ClinicalTrials.gov. Comparisons across studies, however, are difficult as inclusion criteria vary widely. Additionally, the terms xerostomia and hyposalivation are often not separated. Thus, the aim of the present work was to develop a dry mouth severity score (DMSS) that incorporates published questionnaires and measures both xerostomia and hyposalivation and proposes a grading system that can be used as a common basis for inclusion into clinical trials. The DMSS was developed through the use of data from patients in the Dry Mouth Clinic, University of Oslo, Norway. Five groups of patients (n = 131) and controls (n = 59) were included: primary Sjögren’s syndrome, non-Sjögren’s syndrome, radiated head and neck cancer, psychiatry, and controls. The proposed DMSS includes five parameters with corresponding cut-off values given 1 point (p) each: the General Xerostomia Question ≥ 2, Summated Xerostomia Inventory ≥ 11, Clinical Oral Dryness Score ≥ 6, and secretion of unstimulated and chewing-stimulated whole saliva with cut-off values at ≤0.1 mL/min and ≤0.7 mL/min, respectively. The proposed score range for DMSS is 0–3, where score 0 corresponds to 0p, score 1 to 1–2p, score 2 to 3p, and score 3 to 4–5p. In the patient group, 65% had a high DMSS of 2 or 3, while 78% of the controls scored 0. The sensitivity and specificity were high (0.93 and 0.78, respectively), and the internal reliability was satisfactory (Cronbach’s alpha 0.80). The proposed DMSS represents a novel method to uniformly classify dry mouth patients for applicable comparison between clinical trials.