This study aimed at collecting data of masseter myofascial tension, related to the joint hyperactivity by electromyography activity of masseter muscle at rest, isotonic and isometric chewing. 08 patients living in the city of Buenos Aires, Argentina, volunteers, aged between 22 and 62 years, both sexes were evaluated. The electromyography data collection at rest had reported that 50% showed differences in masseter muscle tension increased in the left for the right masseter; in isometric contraction, 50% had a difference in masseter tension right; in isotonic contraction 62.5% there was a difference in increased tension in the left masseter. Anthropometry of the face was suggested, where 25% showed significant variance of 01 cm of discrepancy on the right, in relation to the left. It is possible in the future, an early diagnosis and treatment, thus avoiding a source of pain, speech disorders and problems in the mastication system. For this we need to establish a direct follow-up control of at least one year after the treatment strategy.