The temporomandibular joint (TMJ) is where the jaw joint connects with the skull. It works like a sliding hinge, one on each side of the jaw. TMJ disorders are a type of temporomandibular disorder (TMD) and can cause pain in the jaw joint as well as the muscles that control jaw movement.
TMJ can result from a variety of factors, such as genetics, arthritis, or jaw injury; the exact cause can be difficult to determine. For many people affected by it, the pain and discomfort associated with TMJ disorders is temporary and can be relieved with home remedies or other nonsurgical treatments. Leaving the disorder untreated can have consequences on the jaw and/or teeth, such as damage to the teeth (due to teeth grinding) or misalignment of the jaw. The object of a TMJ evaluation is to determine whether the pain and discomfort that a patient might be experiencing is the result of a TMJ disorder or simply due to muscular issues or a misaligned bite.
The exam to diagnose a TMJ disorder involves an inspection of how the joint acts and sounds while the patient opens and closes their mouth, simulates chewing, and clenches their teeth. The dentist can tell, by feel, whether or not the jaw has unusual movement. A stethoscope may be used to detect sounds of popping, clicking, or grinding. The range of motion of the jaw will also be tested. Different areas of the jaw will be pressed to determine the exact sites of pain or discomfort. X-rays may be taken to provide a closer look at the teeth, CT scans provide detailed images of the bones involved in the joint, and MRIs can show problems with the joint’s disk.