Abstract
Purpose: The purpose of this study was to decrease the burden in both patients and clinicians, and to improve measurement accuracy, in a system to calculate biting forces during clenching from electromyograms of masticatory muscles.
Methods: We first calculated a representative regression formula in all the subjects, and a regression formula of respective integrated electromyograms (I-EMG), and evaluated the error of the calculated values of biting forces. We also attempted to simplify the calculation method. Then, we evaluated the correlation between the coefficient (β) in the regression formula and various related factors, such as the area of the lower denture base, to determine the factors that were related to the coefficient (β) in the regression formula.
Results: The error of the values of biting forces that were calculated from the representative formula in all the subjects, was 32% compared with the actually measured values. Regarding the representative formula of respective I-EMGs, it was shown that the error of the calculated values of biting forces was less than 19% in the subjects with maximum values of I-EMG of less than 6.0μV·s, and less than 25% in the subjects with maximum values of I-EMG of more than 6.0μV·s. The correlation with the coefficient (β) was higher in the order of the buccolingual cross-sectional area of the alveolar ridge in the lower posterior tooth region, the maximum value of I-EMG, the buccolingual width of the alveolar ridge in the lower posterior tooth area, the area of lower jaw denture base, the age of the subject, and mandibular corpus height.
Conclusions: These results suggested that it was necessary to determine the representative formula by classifying the subjects based on the related factors to the coefficient (β) in the regression formula.
