Reproducibility and Validity of Masticatory Sounds in Assessing Consecutive Masticatory and Deglutition Functions

Abstract

This study investigates the reliability and interday reproducibility of consecutive sounds from chewing to swallowing under standardized conditions, aiming to establish convergent validity with occluding force and the glucose elution method. Seven males and four females, aged 28.3±2.4 years, participated. Baseline measurements included occlusal force and masticatory performance. In a soundproof room, participants chewed almonds at a set rhythm, with sounds recorded continuously from chewing onset to swallowing. Recordings were processed using time series analysis software, extracting the first 10 seconds for frequency analysis and dB sum of squares calculation. The process was replicated three times, and the average was used. Interday reliability was assessed by replicating the entire procedure on day -1 and day -2. Intraday reliability for the dB sum of squares was evaluated using the intraclass correlation coefficient (ICC: 1, 3) separately for each day, with a paired ttest. Simple regression analysis explored associations between dB sum of squares, occlusal force, and glucose elution. Results demonstrated excellent agreement and high reliability across data sets within and between days (day -1: 0.97, day -2: 0.91) . A significant negative linear association was observed between the dB sum of squares and occlusal force two, thus, convergent validity was confirmed with occlusal force but not with masticatory performance. These findings suggest potential targets for therapeutic interventions in patients with impaired masticatory function. Future studies will extend examinations across age groups and oral health levels, following the established protocol.