Evaluation of Masticatory Muscle Tone by Analyzing Vertical Mandibular Movement with Electric Stimulation

Masticatory muscle tone was investigated by analyzing vertical mandibular movement with electric stimulation. Healthy subjects and patients with type I TMD wereexamined. Under various conditions, masticatory muscle tone was evaluated by recording vertical dimension and velocity of mandibular movement.The results were as follows:1. Ten stimulations were applied with the mandible in the resting position. The descending dimension and maximum velocity of descent were measured.2. The mental anxiety of the subjects only slightly affected the mandibular movement with electric stimulation.3. Both parameters were lower in TMDpatients than in healthy subjects.4. Both of these values were lower before treatment for TMD than after treatment, and the values after treatment became similar to those in healthy subjects.