Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 5 4 2019 06 10 143 147 Shamsolmolok Najafi Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Reyhane Palizgir School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran. Nafise Sheykh Bahaei Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Javad Kharazi Fard Department of Epidemiology and Biostatistics, School of Public Health, Tehran University Of Medical Sciences, Tehran, Iran. 2019 06 10 Introduction: Temporomandibular disorder (TMD) is a very common disorder in modern  societies. This disease is caused by disturbance in the masticatory system and joints, leading to various symptoms such as pain, reduced maximum mouth opening, deviation, deflection and joint clicking sound. The clicking sound, which is a kind of joint sound, is one of the most important  side effects of TMD. The present study was conducted to examine the effect of transcutaneous electrical nerve stimulation (TENS) on temporomandibular joint (TMJ) clicking sound. Materials and Methods: Seventeen patients with TMD who had clicking sound were selected. The TENS unit was used for patients twice a week for ten sessions. The clicking sound in patients was recorded before and after the treatment. Data were analyzed using SPSS version 21 and McNemar’s test. Results: The results of the study showed that the average values of joint sound in the pretest was 1.000, and decreased to 0.647 in the posttest and this decrease was statistically significant (p=0.031). Conclusion: TENS can be used as a therapeutic technique to reduce joint sounds. Keywords: Clicking sound; Joint sound; Tens; Temporomandibular disorder. https://jcr.tums.ac.ir/index.php/jcr/article/view/281 https://jcr.tums.ac.ir/index.php/jcr/article/download/281/249