TMD, TMJ – Temporomandibular Joint Disorder (TMD) is a common condition that limits the natural functions of the jaw, such as opening the mouth and chewing. It currently affects more than 10 million people in the United States. It is sometimes incorrectly referred to as simply “TMJ,” which represents the name of the joint itself. TMD affects more women than men and is most often diagnosed in individuals aged 20-40 years. It can cause poor posture, chronic jaw clenching, poor teeth alignment, and fractures or conditions such as lockjaw, where the muscles around the jaw spasm and reduce the opening of the mouth. Physical therapists help people with TMD ease pain, regain normal jaw movement, and lessen daily stress on the jaw.