What Causes TMJ and TMD?Temporomandibular disorder (TMD) also known as TMJ occurs when the jaw joint has become inflamed or is not functioning properly. If you are experiencing pain around the jaw or facial muscles that control the jaw, you may have TMJ. The root cause of this condition is still unknown but may be traced to bruxism (teeth grinding), osteoarthritis or trauma to the mouth and jaw. Learn more about undergoing treatment for TMJ in Sonoma, CA, by scheduling your appointment with Dr. Yoshioka today.