Abstract: Objective: To investigate the effect of transcutaneous electrical nerve stimulation (TENS) on somatosensory and jaw function in patients with unilateral temporomandibular joint (TMJ) pain. Methods: Twenty patients with unilateral TMJ pain and 20 healthy controls were assigned randomly and double-blinded into two groups to receive real and sham TENS (rTENS and sTENS) stimulation for 30 min in a randomized order. mechanical pain threshold (MPT), pressure pain threshold (PPT), opening range (OR) without pain and maximal OR were tested before (T1), immediately after (T2),and 30 min after treatment (T3). Results: PPTs and ORs of patients were lower than normal's (P_PPT=0.034,Pno pain<0.001,Ppain<0.001). There were significant differences for MPT and PPT between painful and control sides in patients (P_MPT<0.001, P_PPT<0.001). MPTs, PPTs and ORs were significantly different between pre- and post-treatment (rTENS) (P_MPT=0.003, P_PPT<0.001, Pno pain<0.001, Ppain<0.001). Conclusion: TMJ pain patients demonstrated high sensitivity and limitation of jaw motion. TENS showed significant improvement in terms of somatosensory and motor function in patients with unilateral TMJ pain

Key words: Temporomandibular disorders, Transcutaneous electrical nerve stimulation, Pain, Quantitative sensory testing