Functional status of mastication muscles in 44 patients of the age 19-35 years with close position of frontal teeth and different occlusion variants was studied. General electric activity of mastication and temporal muscles (IMPACT, mkV/s), index of proportional activity of symmetric muscles (capital ER, Cyrilliccapital O, Cyrilliccapital ES, Cyrillic, %), activation index (ATTIV, %) and torque coefficient (TORS, %) were determined. According to the received results in patients with close position of frontal teeth and different occlusion variants some disbalance was disclosed in the work of mastication muscles that testified to functionally unstable occlusion and the necessity of its correction.