Effect of Occlusal Splints on the Electromyographic Activities of Masseter and Temporal Muscles During Maximum Clenching

Abstract

Objectives
Despite the broad use of occlusal splints their efficacy is a source of controversy. In this study the effectiveness of stabilization splint on the electromyographic activity of the masseter and temporal muscles in healthy individuals was investigated.

Method and Materials
The stabilization splint was made for twenty-five healthy individuals. Surface EMG recordings of masseter and temporal muscles were done during maximum clenching without the splint and immediately after application of splint. The relative level of activity in the masseter and temporal muscles was quantified by means of Activity Index. Paired t-test and Wilcoxan signed -rank test were used for data analysis.

Results
The mean EMG activities of masseter and temporal muscles were 0.7712 and 1.0488 without splint and 0.8396 and 0.9276 with splint. There was no significant difference between the EMG activities ofboth muscles before and after insertion of the splints. The activity index increased after application of the stabilization splint. (-17 .15 VS -4.4). This increase was also insignificant.

Conclusion
Immediate application of stabilization splint has no significant effect on the activity of masseter and temporal muscles. It could decrease the relative activity of the temporal to the masseter muscle (increasing of activity index).

Key Words
Electromyography, Masseter physiology, Temporal physiology, Muscles physiology, Maximum clenching, Occlusalsplint.