ELECTROMYOGRAPHIC ACTIVITY OF HUMAN MASTICATORY MUSCLES IN NORMAL YOUNG-PEOPLE - STATISTICAL EVALUATION OF REFERENCE VALUES FOR CLINICAL-APPLICATIONS

Electromyographic activity of anterior temporal and masseter muscles w as measured in 92 young healthy men and women with sound dentitions du ring rest position, contact in centric occlusion and clench. Male and female mean potentials were similar except in clench, where males had higher electromyographic levels. Mean pooled electromyographic potenti als were 1.9 muV (TA) and 1.4 muV (MM) during rest position, 6.5 muV ( TA) and 2.8 muV (MM) during contact in centric occlusion. Mean maximum voluntary clench potentials were 181.9 muV (TA) and 216.2 muV (MM) in men, 161.7 muV (TA) and 156.8 muV (MM) in women. Examined muscles wer e more asymmetric at low electromyographic activity (rest and centric occlusion) with the temporal muscle less asymmetrical than the massete r. In females temporal muscle activity tended to dominate at every con traction level, while in males masseter activity was stronger in clenc h, and temporal activity in centric occlusion and in rest position.