Temporomandibular disorders (TMDs) are a group of more than 30 conditions that cause pain and dysfunction in the jaw joint and muscles that control jaw movement. “TMDs” refers to the disorders, and “TMJ” refers only to the temporomandibular joint itself. People have two TMJs; one on each side of the jaw. You can feel them by placing your fingers in front of your ears and opening your mouth.

There are three main classes of TMDs:

There are several disorders within each class.

Many TMDs last only a short time and go away on their own. However, in some cases they can become chronic, or long lasting. In addition, TMDs can occur alone or at the same time as other medical conditions such as headaches, back pain, sleep problems, fibromyalgia, and irritable bowel syndrome. Temporomandibular disorders are twice as common in women than in men, especially in women between 35 and 44 years old.

Injury to the jaw or temporomandibular joint can lead to some TMDs, but in most cases, the exact cause is not clear. For many people, symptoms seem to start without obvious reason. Recent research suggests a combination of genes, psychological and life stressors, and how someone perceives pain, may play a part in why a TMD starts and whether it will be long lasting.

Because TMDs are more common in women than in men, researchers are exploring whether the differences in TMJ structure and mechanics between females and males may play a role.

It is important to know that sounds (such as clicking or popping) without pain in the TMJs are common, are considered normal, and don’t need treatment.

However, the following symptoms may signal a TMD:

There is no widely accepted, standard test available to diagnose TMDs. Because the exact causes and symptoms are not clear, identifying these disorders can be difficult.

Your doctor or dentist will note your symptoms and take a detailed medical history. He or she will ask questions about your pain, including its location, when it occurs, what makes it better or worse, and if it stays in one area or spreads to other parts of your body. The doctor or dentist will also ask if you have other pain conditions such as headache or back pain.

He or she also will examine your head, neck, face, and jaw for tenderness; jaw clicking or popping; or difficulty with movement. The doctor or dentist might also suggest imaging studies such as an x-ray, magnetic resonance imaging (MRI), or computed tomography (CT).

Pain in the mouth, jaw, or face may or may not be related to TMDs. Your doctor or dentist may have to rule out other conditions before diagnosing a TMD.

Before receiving treatment for TMDs, you should know: