Objective: The aim of the present study was to evaluate the effects of ultra-low-frequency transcutaneous electrical nerve stimulation (ULF-TENS) on pain and electromyographic values in subjects affected by temporomandibular disorders. Methods: A retrospective evaluation of 80 non-consecutive patients (58 women, 22 men, mean age 35.3 ± 9.9 years) suffering from pain associated with temporomandibular disorders was performed. The sample was treated with ULF-TENS, and outcomes were evaluated by anamnestic index, dysfunction index, visual analog scale, and surface electromyography of the masticatory muscles. Results: An improvement was seen in pain and electromyographic values. The visual analog scale showed a mean decrease from 8 to 2; surface electromyographic values in the masseter area decreased from 2.7 ± 0.1 to 1.5 ± 0.1. Conclusion: ULF-TENS seems to be effective in reducing pain symptomatology of subjects affected by temporomandibular disorders, with a reduction in the surface electromyographic activity in the masseter area.
Keywords: Temporomandibular disorders; electromyography; facial pain; masseter muscles; transcutaneous electrical nerve stimulation; visual analog scale.