抄録
This study was performed to determine whether or not malocclusion decreases the interdependent relationship between the chewing path and muscle activity. For experimental premature contact attached to the lower 1st molar on the habitual chewing side, two thicknesses (50 μm and 100μm) of metal foil were used. Chewing movements using a stick of gum were recorded simultaneously as the path and electromyograms. The parameters for the path were the amount of anterior-posterior and right-left movements at 1 mm, 7 mm and lowest point vertically below the intercuspation in the opening-closing path and the maximum amount of mouth opening per stroke, and those for electromyograms were the interval of EMG bursts and the integrated in the central portion of the bilateral masseter muscles and the anterior portion of the bilateral temporal muscles. The presence or absence of premature contact, and changes in the relationship between the chewing path and muscle activity according to the thickness of interference were analyzed in terms of the first canonical correlation coefficient in canonical correlation analysis. Premature contact could be a factor that decreases the first canonical correlation coefficient, but no differences were observed between the two thicknesses.
