Masseter electromyographic changes as a function of vertical dimension in patients with MPD syndrome

The aim of the present work was to study the relation between vertical dimension (VD) and basal tonic electromyographic (BT-EMG) in 62 subjects with bruxism and myofascial pain dysfunction (MPD) syndrome. The vertical dimension was varied statistically or dynamically from 1 to 15 mm interocclusal distance: BT-EMG activity, first decreased, and then increased up to the highest values of VD. Minimum BT-EMG activity was observed or a mean VD of 8.45 mm interocclusal distance. The results suggest that the use of occlusal splints adjusted near the VD of least EMG activity may be an important factor influencing effectiveness in the treatment of muscular spasm in bruxism and MPD syndrome.