title: [Evaluation of masticatory comminute function using multiple variables--Part. I: Observation of mastication using inter-jaw positional EMG].
abstract: When masticatory efficiency is measured in the normal manner, it is necessary to collect samples. The purpose of this study was to devise a possible method of measuring masticatory efficiency, obviating the necessity for collection of the sample. Peanuts mastication by subjects whose degree of comminution was already known was observed by using an "Inter-jaw positional EMG" in which an element of the jaw positions is combined with EMG. Observation of the Inter-jaw positional EMG enables understanding the appearances of each 1-cycle chewing comminution. Moreover, changes in muscle activity and jaw movement caused by the progress of mastication can be observed by arranging the Inter-jaw positional EMG to record the chewing cycle, several times. In addition, three phases in peanut mastication was observed, and it was found that analysis of the first two phases when the changes appear is very effective because the changes move similarly with the changes of particle size. In addition, the Inter-jaw positional EMG and distribution of particle size were analyzed, and both changes caused by the progress of the cycle were similar. Thus, it is possible to estimate of the masticatory efficiency using the Inter-jaw positional EMG.
authors.affiliation: Department of Prosthodontics II, Faculty of Dentistry, Tokyo Medical and Dental University.
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D010367:Arachis; D004576:Electromyography; D006801:Humans; D007568:Jaw / Q000502:physiology*; D008297:Male; D008409:Mastication / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D015999:Multivariate Analysis; D010316:Particle Size