No statistically significant differences between groups were found for the right and left anterior temporal muscles ( P = .3801 and P = .5595 , respectively ) , superior masseter muscles ( P = .087 and P = .1969 , respectively ) , medial masseter muscles ( P = .2241 and P = .076 , respectively ) , or inferior masseter muscles ( P = .5589 and P = .3268 , respectively ) after treatment .