Responsiveness of the different methods for assessing the short-term within-subject change in masticatory function after conventional prosthetic treatments.

Statement of problem. Improvement in the masticatory function after replacing missing teeth is one of the main expected outcomes that need to be comprehensively measured with both clinical and patient-centered assessments. An evaluation of the responsiveness of these methods is lacking. Purpose. The purpose of this clinical study was to assess the responsiveness of both objective and subjective methods for measuring the impact of different conventional prostheses on masticatory function at prosthesis delivery and 2 months later. Material and methods. Participants (N=118) requiring prosthetic rehabilitation were selected from patients attending the Faculty of Dentistry of the University of Salamanca. Masticatory function was assessed by means of subjective methods (self-rated ordinal scales, visual analog scale, and food intake ability questionnaire) at baseline and 2 months after treatment. The ability to mix 2-colored chewing gum after 5, 10, and 15 cycles was also evaluated objectively. The responsiveness of each method was categorized by the effect size (ES) as low (<0.5), moderate (0.5 to 0.8), or large (>0.8). Results. The study revealed that in all subgroups, the masticatory function improved 2 months after the treatment. The most responsive method was the visual analog scale (ES: 1.2) and the number of pattern foods perceived to be easily masticated by participants (ES: 0.7 to 1.3). By contrast, the masticatory performance assessed by using the mixing ability test showed a smaller magnitude of change (ES: 0.3 to 0.7). Both the objective and subjective masticatory functions were coherently correlated with age and clinical variables (number of occlusal units or the Eichner index) in all subgroups. However, masticatory performance and masticatory ability were not significantly correlated (r=0.22; P=.12). Conclusions. Conventional prosthetic treatments significantly improve masticatory function 2 months after delivery, and the subjective methods were the most responsive in assessing changes in participants.