Relationship of masticatory mandibular movements to masticatory performance of dentate adults: a method study

This study evaluated a sieve method for measuring masticatory performance and determined the associations between masticatory performance and masticatory mandibular movements. Ten dentate adults and three complete denture-wearing subjects participated in the study. The masticatory performance indices for these subjects were determined after a 10 s masticatory sequence and another sequence that ended at the swallowing threshold. Almond was used as the test food and almond fragments were sized using a standard 0.65 mm square size brass wire sieve. Masticatory mandibular movements were simultaneously recorded by an optoelectronic device. The reproducibility of the masticatory performance tests was good (r = 0.98 and 0.82 for the 10 s and swallowing threshold test indices, respectively). The masticatory performance indices were markedly different between dentate and denture-wearing subjects. The 10 s masticatory performance index in the dentate subjects, showed moderate to rather strong correlation with all parameters of mandibular velocity (r = 0.6-0.7). The 10 s index also showed a strong negative correlation to the duration of the occlusal level phase and the total duration of the chewing cycle (r = -0.7 to -0.8) in the dentate subjects. This study confirms that masticatory performance levels are relatively stable and associated with the efficacy of specific masticatory mandibular movement parameters.