Temporomandibular Disorders (TMD) refer to conditions associated with jaw movement and pain in and around the jaw. For many people, the temporomandibular joint (TMJ) becomes overworked and stressed, which can lead to TMD. Bruxism is a common form of TMD. It is characterized by grinding, gnashing, or clenching of the teeth. You may unconsciously do this while you are awake (awake bruxism), or clench and grind while you sleep (sleep bruxism). While mild bruxism often requires no treatment, for some people bruxism can be severe and frequent enough that jaw pain and discomfort, headaches, damaged teeth, and other problems arise.