Differences in Lip Support with and without Labial Flanges in a Maxillary Edentulous Population. Part 2: Blinded Subjective Analysis.

Abstract

To study the subjective differences in facial esthetics evaluations among lay people, general dentists, and prosthodontists, when evaluating images of patients wearing a maxillary denture with a labial flange in comparison to an experimental flangeless denture. A random sample of 20 maxillary edentulous patients from the original sample of 31 patients described in part 1 of the study was selected for this study. A total of 60 judges comprising 15 general dentists, 15 prosthodontists, and 30 lay people were recruited for subjective analysis. The judges were blinded about the objectives of the study and were asked to rate the facial esthetics of each image using a 100 mm visual analog scale (VAS) instrument. Four digital images per subject (total of 80 images) were evaluated in a random order, twice by all 60 judges. A repeated measures general linear mixed modeling method using restricted maximum likelihood estimation was performed using mixed procedure in a statistical software package to study the differences in evaluations. The overall VAS ratings of facial esthetics for images with flangeless dentures were slightly lower compared to images with labial flanges, and this difference was statistically significant (p < 0.05). This was true for both profile and frontal images; however, the magnitude of the difference was too small (no greater than 4 mm on a 100 mm scale) to be clinically significant. There were no statistically significant differences in facial esthetics ratings irrespective of the background or gender of the judges. Flangeless dentures resulted in slightly lower ratings of facial esthetics compared to images with a labial flange, but the differences were clinically insignificant. This was true for all judges comprising general dentists, prosthodontists, and lay people and for both frontal and profile images.