Comparative effectiveness of Low Level Laser therapy and Transcutaneous Electric Nerve Stimulation on Temporomandibular Joint Disorders

Abstract

IntroductionTemporomandibular joint disorder (TMD) is a general term for clinical problems in temporomandibular joints (TMJs), masticatory muscles, and surrounding tissues, which manifest as limitations in motion and joint sounds. 1 TMD is the second most-common skeletal-muscular problem and one of the most common chronic problems involving orofacial pain, discomfort and disability. Approximately 75% of the population has several symptoms of TMD and 33% have at least one symptom. 2-5The etiology of TMD, especially muscle pain, is multifactorial and includes parafunctional habits, trauma, stress, heredity and occlusal factors 5 ; thus, conservative and reversible treatment, especially during initial periods, is recommended. 5,6 Several treatments have been suggested to control pain and symptoms. These include orthopedic stabilization, intraoral devices, medications (analgesics, muscle relaxants, antidepressants, and placebos) and physical therapy. 5 The aim of physical therapy is muscle relaxation, a decrease in pain, spasms, swelling and inflammation, and joint stability. Methods:In this single-blind study, 40 patients with temporomandibular disorders were randomly divided into four groups: TENS (TENSTem dental), LLL (diode 810 nm CW), sham-TENS, and sham-LLL. All subjects were examined and data on pain and tenderness in the temporomandibular joint (TMJ) and masticatory muscles (using the visual analogue scale) and mouth-opening (distance between incisal edges before feeling pain; mm) were collected before baseline (T1), after each session (T2-T5) and one month after the end of the sessions (T6)), and analyzed using repeated measure analysis of variance (ANOVA) and Bonferroni statistical tests. A P value < 0.05 was considered significant. Results:The decrease in pain (P = 0.000), tenderness (P = 0.000) and increase in mouth-opening ability (P = 0.002) was greater in the TENS and LLL groups than in the placebo groups. At the one-month follow-up, significant decrease in pain and tenderness was recorded in the TENS and LLL groups (P = 0.000). There was no significant differences between TENS and LLL and the placebo groups for maximum mouth-opening at the end of the study (P = 0.692). Conclusion: Using TENS or LLL therapy can improve TMD symptoms at least for the short term. Although the effects of the placebo played a role in improving symptoms, their effects were less important.

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

“…The study by Kato.et al [10] and Sei .et al [12] revealed that both LLLT and TENS caused a noticeable decrease in painful symptoms for the short term, which may account for the cumulative effect. Nunez.et al [14] supported that LLLT was more e cient than TENS in improving the amplitude of mandibular movement.…”

“…Then 55 potentially eligible articles were obtained by screening the titles and abstracts carefully. After careful full-text screening and assessment of the risk of bias, 20 RCTs met the inclusion criteria [4,10,12,15,28,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48]. This selection process and exclusion reasons were presented in the ow chart (Fig.…”

“…Meanwhile, LLLT can be applied to treating a variety of conditions, including damaged wound, pain and in ammation [14]. Although TENS is easier to use than LLL because of its small size, low risk, and convenient portability, the current delivered to the skin through TENS may make some patients uncomfortable [12]. Some experts observed that patients were easy to accept LLLT during the treatment process because LLLT does not emit heat, sound, vibration or light in the infrared spectrum, making it indistinguishable from placebo therapy.…”

“…Its exact mechanism of pain control is unknown. Reports suggested that this might occur because of increased release of endogenous negative ions, improved local microcirculation, or increased lymph ow, thereby reducing edema, increasing ATP production, and decreasing the permeability of nerve cell membranes [12,13]. TENS has also widely applied in the clinic given its analgesic and muscle relaxing effect, with positive results [10,14].…”

“…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]. But there were only limited data comparing their relative e cacy with each other, and the statistical power was insu cient.…”