Abstract
Effect on the masseter muscle activity was studied electromyographically and kinesiographically comparing hard and soft occlusal splint wearers during tapping movement.
Five subjects having normal occlusion were used in this study. Surface EMGs of the masseter muscle were recorded before and immediately after wearingeither hard or soft splints, 3 days and 7 days after wearing splints, and 7 days after removal ofsplints. And then those data were analyzed.
The results were as follows:
1. In the maximum opening distance during tapping movement, hard splints showed lesschanges over time, whereas it increased in soft splints.
2. In the EMG time parameters, influential changes were observed in soft splints.
3. CV values of the EMG time parameters tended to increase after wearing soft splintscompared to hard splints.
4. Integrated potential of the EMG decreased somewhat over time after wearing hardsplints, but increased markedly immediately after wearing soft splints.
5. CV values of the integrated potential of the EMG showed remarkable increase in softsplints compared to hard splints.
The above results revealed that compared to hard splints, soft splints exhibited influentialchanges of the masseter muscle activity by increasing its muscle activity.
