A risk factor is something that increases your likelihood of getting a disease or condition.

It is possible to develop TMD with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing TMD. If you have a number of risk factors, ask your doctor what you can do to reduce your risk.

Risk factors for TMD include:

Some of the stress-related habits that may increase your risk of TMD include:

  • Habitually clenching and unclenching your jaw
  • Lip biting
  • Grinding your teeth during the day and/or at night in your sleep
  • Constantly or very regularly chewing things, such as gum or ice, for long periods of time

The following medical conditions may increase your risk of TMD:

  • Misaligned teeth or misaligned bite
  • Jaw or facial deformities
  • Arthritic conditions, such as:
  • Synovitis, an inflammation of the membrane that lines the temporomandibular joint
  • History of jaw or facial injuries such as fractures or dislocations of the jaw
  • Muscle pain or spasm of the chewing muscles
  • Psychological illness

Most people report TMD symptoms between the ages of 30 and 50.

TMD is more common in women than in men.

Poorly fitted dentures are thought to be a risk factor for TMD.

There is some evidence that women taking hormone replacement therapy are more likely to develop symptoms of TMD.