Introduction:The normal function of the stomatognathic ystem (SMS) depends on the harmony of close relationship among temporomandibular joint (TMA), occlusion and neuromuscular system.This study described this SMS characteristics of young adult people.Methods: Descriptive study, intention sample of 60 patients with complete natural dentition that observed the main occlusal characteristics, TMA and temporal and masseter muscles, through, clinical examination, mounting semi-adjustable articulator and surface electromyography.Results: Patients recorded: ATM noise (43%), limited opening (13%), normalocclusion in static position (56-71%), premature contacts (20%) interferences (93%) and opening deviation (51 %).In patients with occlusal alterations there was an increase in muscle electrical activity (right masseter p<0.05). Conclusion:Clinical and occlusal conditions that did not coincide with normalocclusion parameters generated an increase in muscle electrical activity.