TMJ, or temporomandibular joint disorder, refers to a group of conditions affecting the jaw joint and surrounding muscles. This joint connects the jawbone to the skull, allowing for movements like chewing and speaking. Symptoms can include pain in the jaw, difficulty opening the mouth, and clicking or popping sounds when moving the jaw. The causes of TMJ can vary and may include jaw injuries, arthritis, or teeth grinding, known as bruxism. Treatment options often involve pain relief methods, physical therapy, or dental appliances to help manage symptoms and improve jaw function.