Comparison of the effectiveness of three different conservative methods in myogenous temporomandibular disorders

OBJECTIVE: The aim of this study was to compare the effectiveness of exercise, transcutaneous electrical nerve stimulation, and manual therapy on pain intensity, maximum mouth opening, and masticatory muscle activity-during chewing of the masseter and temporalis anterior in myogenous temporomandibular disorders. METHODS: A total of 51 myogenous temporomandibular disorders patients were randomly assigned to three groups: exercise group, transcutaneous electrical nerve stimulation group, and manual therapy group. For 6 weeks, exercise group received exercise only, transcutaneous electrical nerve stimulation group received exercise+transcutaneous electrical nerve stimulation, and manual therapy group received exercise+manual therapy. At baseline and after 6-week treatment, pain intensity was assessed using a visual analog scale, maximum mouth opening using a millimeter ruler, and masticatory muscle activity-during chewing of the masseter and temporalis anterior using surface electromyography. RESULTS: After treatment, significant improvements in pain intensity, maximum mouth opening, and masticatory muscle activity-during chewing values were found in all the three groups. The greatest improvements were seen in manual therapy group. The decreases in pain intensity and increases in masticatory muscle activity-during chewing values were statistically significantly higher in transcutaneous electrical nerve stimulation group than in exercise group (p<0.05). The increases in maximum mouth opening were similar in transcutaneous electrical nerve stimulation group and exercise group. CONCLUSION: Exercise is an effective method for improving pain intensity, maximum mouth opening, and masticatory muscle activity-during chewing in myogenous temporomandibular disorders. Combining exercise with manual therapy may provide the highest therapeutic effect on these parameters. Combining exercise with transcutaneous electrical nerve stimulation may also lead to further improvements in pain intensity and masticatory muscle activity-during chewing.