Myoelectrical activity of clinical rest position and jaw muscle activity in young adults.

Electromyographic activity of anterior temporal, superficial masseter, deep masseter and anterior digastric muscles was measured in 40 young healthy men and women during rest (at the beginning and the end of tests), clench, maximal opening, lateral displacement and CR manipulation. During initial rest position myoelectrical activity was 1.9 microV increasing to 2.1 microV at the end of tests (P = 0.08). During clench and maximal opening no significant differences between the sexes were found. The digastric muscle showed considerable activity during maximal opening, lateral displacement and CR manipulation.