Diagnosis of TMJ can be done by a doctor or dentist. They will most likely start with an evaluation that includes your medical history. You may be asked about any past accidents or head trauma, or whether you experience ear pain or pain when chewing. Feeling around the area of the jaw and applying light pressure can let the doctor or dentist know if your TMJ is out of alignment. The doctor or dentist can also watch as you open your mouth and see how the jaw is opening. Some dentists may use tools to determine if you have poor bite alignment. If the jaw moves to one side or another, or if there is a popping or clicking sound, it may be an indicator that you have TMJ disorder.
Other, more advanced ways of checking for TMJ disorder use imaging techniques such as dental X-rays, CT Scans, or MRI. The X-rays are used to see if there are abnormalities in the bones near the joint, the CT scans help to see the bony detail of the joint itself, while the MRI can make it possible to see the tissues surrounding the joint. A combination of a physical evaluation and imaging are most likely what your doctor or dentist will use to check for TMJ disorders.