Determination of Cutoff Values on the 100-mm Visual Analogue Scale to Classify the Satisfaction Levels of Complete Denture Wearers

Purpose: The purpose of this study was to determine the optimum cutoff values on a 100-mm visual analogue scale (VAS) for assessing patients'level of satisfaction with their complete dentures, and to extend its use in the clinical setting.Methods: Cross-sectional consecutive sampling was conducted to gather subjective ratings of existing complete dentures using both VAS and a four-point verbal descriptive scale (VDS). Eighty-two edentulous individuals (39 male and 43 female; mean age: 71.6±8.1years) participated in the study. The satisfaction ratings for existing dentures were measured using both the VAS and the four-point VDS at baseline. Agreement between the patient ratings on the VAS and the four-point VDS was analyzed by Spearman rank correlation coefficient, and the cutoff values were estimated by analysis of the receiver operating characteristics (ROC).Results: There was significant agreement between the patient ratings on the VAS and the four-point VDS (overall: r=0.84, P<0.001; maxillary: r=0.75, P<0.001; mandibular: r=0.81, P<0.001). The cutoff points on the VAS were clarified for the overall (dissatisfied: 0–31; slightly dissatisfied: 31+–50; slightly satisfied: 50+–79; satisfied: 79+), maxillary (dissatisfied: 0–47; slightly dissatisfied: 47+–52; slightly satisfied: 52+–80; satisfied: 80+), and mandibular (dissatisfied: 0–36; slightly dissatisfied: 36+–48; slightly satisfied: 48+–83; satisfied: 83+) satisfaction.