Short-term transcutaneous electrical nerve stimulation reduces pain and improves the masticatory muscle activity in temporomandibular disorder patients: a randomized controlled trial

Abstract

Studies to assess the effects of therapies on pain and masticatory muscle function are scarce. Objective To investigate the short-term effect of transcutaneous electrical nerve stimulation (TENS) by examining pain intensity, pressure pain threshold (PPT) and electromyography (EMG) activity in patients with temporomandibular disorder (TMD).Material and Methods Forty patients with myofascial TMD were enrolled in this randomized placebo-controlled trial and were divided into two groups: active (n=20) and placebo (n=20) TENS. Outcome variables assessed at baseline (T0), immediately after (T2) and 48 hours after treatment (T1) were: pain intensity with the aid of a visual analogue scale (VAS); PPT of masticatory and cervical structures; EMG activity during mandibular rest position (MR), maximal voluntary contraction (MVC) and habitual chewing (HC). Two-way ANOVA for repeated measures was applied to the data and the significance level was set at 5%.Results There was a decrease in the VAS values at T1 and T2 when compared with T0 values in the active TENS group (p<0.050). The PPT between-group differences were significant at T1 assessment of the anterior temporalis and sternocleidomastoid (SCM) and T2 for the masseter and the SCM (p<0.050). A significant EMG activity reduction of the masseter and anterior temporalis was presented in the active TENS during MR at T1 assessment when compared with T0 (p<0.050). The EMG activity of the anterior temporalis was significantly higher in the active TENS during MVC at T1 and T2 when compared with placebo (p<0.050). The EMG activity of the masseter and anterior temporalis muscle was significantly higher in the active TENS during HC at T1 when compared with placebo (p<0.050).Conclusions The short-term therapeutic effects of TENS are superior to those of the placebo, because of reported facial pain, deep pain sensitivity and masticatory muscle EMG activity improvement.

Placebo and nocebo response magnitude on temporomandibular disorder‐related pain: A systematic review and meta‐analysis

“…Risk of bias was very heterogeneous among studies. Using Cochrane Collaboration's tool, nine studies were classified as low risk of bias, 13 as unclear and 20 as high risk of bias . The higher risk of bias was reporting bias.…”

“…Out of the 42 RCTs, sample size ranged from 13 20 to 99 21 with a total of 1657 patients, mostly women, that is from 47 22 up to 100% 23-31 of the sample. Studies were conducted in Brazil, 23,26,28,30,[32][33][34][35][36][37][38][39] Canada, 24,40 China, 41 Croatia, 20 Denmark, [42][43][44] India, 45 Iran, 29,46 Italy, 21 Korea, 22 Poland, 47 Spain, 48 Sweden, [49][50][51] Thailand, 52 the Netherlands, 53 Turkey, [54][55][56] United Kingdom 57 and United States of America (USA). 25,27,31,[58][59][60][61] All studies were published in the English language.…”

“…Propranolol significantly reduced a composite pain index but did not decrease other clinical and experimental pain ratings. , 23,26,33,36,39,41,50,53,56 13 as unclear 20,27,30,37,38,[48][49][50][51]54,55,59,61 and 20 as high risk of bias. 21,24,25,28,29,31,32,34,40,[42][43][44][45][46][47]52,57,58,60,62 The higher risk of bias was reporting bias.…”

Electric Stimulation Hyperthermia Relieves Inflammation via the Suppressor of Cytokine Signaling 3-Toll Like Receptor 4 Pathway in a Prostatitis Rat Model

“…ES as a new and developing treatment has been applied in clinical settings for many years. Ferreira et al [19] found that the temporomandibular disorder treatment process, ES mitigated pain and improved masticatory muscle activity efficiently, without drugs or the need for invasive procedures. Rajfur et al [10] found that electrical therapy was effective in treating chronic low back pain.…”

Comparative effectiveness of low-level laser therapy and transcutaneous electric nerve stimulation in the treatment of pain caused by temporomandibular joint disorders: a systematic review and network meta-analysis

“…Ferreira.et al [15,28] proved that the therapeutic effects of TENS are superior to those of the placebo. In recent years, several RCTs compared LLLT with TENS for treating patients suffering from TMD [10,12,14,29].…”