Temporomandibular disorder (TMD) is a collective term used to identify a group of musculoskeletal conditions of the temporomandibular region. Bruxism is a non-functional activity characterized by repeated tooth clenching or grinding in an unconscious manner. Over the time bruxism may lead to TMD by the uploading it causes. Nasal obstruction is a common complaint that necessitates mouth breathing when severe. The treatment of bruxism is frequently performed by oral appliances, which induce occlusal disengagement and relax jaw musculature and therefore reduce the force on the temporomandibular joint (TMJ). We believe that nasal obstruction may indirectly have a preemptive and therapeutic effect on sleep bruxism related TMD by causing mouth breathing. (C) 2010 Elsevier Ltd. All rights reserved.