The temporomandibular joint system is made of a combination of bones, muscles, cartilage, nerves and fluids that work together to permit movement.

The lower jawbone, or mandible, connects with the temporal bone at the side of the skull near the ear. Each side of the mandible has a rounded structure called the mandibular condyle. The condyle fits into a depression in the temporal bone called the temporal fossa. Both the mandibular condyle and the temporal fossa are covered with cartilage. A soft, thin, oval-shaped disc fits between the condyle and the fossa. The disc acts as a buffer between the mandibular condyle and the skull. The disc absorbs shock and smoothes jaw movements.

2. How did I get TMJ?

Research has not yet determined all the possible causes of TMJ diseases. Many theories of causation have been proposed, but few have been scientifically validated. We do know that TMJ can be precipitated or aggravated by trauma, certain health care procedures, oral habits and postures, and other diseases such as osteoarthritis and fibromyalgia. However, TMJ symptoms are known to occur without an identifiable cause.

Trauma Auto accidents, sports injuries, and blows to the head or neck have been identified as factors in the development of TMJ diseases and disorders. Such events trigger pain and dysfunction in the jaw joints through several mechanisms by shearing and tearing of facial soft and hard tissues, such as:

• teeth
• muscles
• nerves
• ligaments
• bones, and including the traumatic displacement of the articular disk

Jaw mobility can also be limited by scar tissue formation following injury or repair.

3. Health care procedures

Various dental procedures appear to precede the development of TMJ in some patients. We frequently hear from patients who experience muscle spasms, jaw popping and clicking, and jaw joint pain after such procedures as the removal of wisdom teeth, root canal therapy, and bridgework. Prolonged jaw opening in the process of dental treatments can exacerbate existing problems. Poorly fitting caps, bridges, fillings, and dentures can affect the alignment of the bite and the jaw joint as a whole, contributing to symptoms.

Intubation during a surgical procedure can aggravate conditions of the jaw joint and surrounding musculature. Because the jaw must remain fixed in a widely opened position for the duration of the surgery, anyone suffering from a TMJ condition should inform the anesthesiologist of this problem prior to undergoing any operation requiring intubation.

4. Posture and Oral Habits

Any activity that causes the head to be held in an unnatural position may intensify TMJ problems. Particularly troublesome habits including cradling a telephone between the ear and shoulder, carrying a heavy shoulder bag, and slumping over a desk to read or type. Playing certain musical instruments and singing can also exacerbate TMJ symptoms. If pain in the head, jaw, neck, or shoulders is associated with a habitual movement, an ergonomic solution may be considered, i.e., a hands-free telephone headset, pull-along luggage, ergonomic seating, lighting and keyboards for the office.

People with certain oral habits may aggravate TMJ symptoms. Oral habits such as nail biting, pencil chewing, tongue thrusting, and wide yawning can increase a patient's symptoms. These habits can also place the jaw joint in an abnormal position and further compromise jaw structure and function. Certain foods can also be problematic. Hard, crunchy foods and foods requiring a person to open the mouth widely can also trigger painful symptoms. These foods should be avoided if a TMJ disease is present.

5. Who gets TMJ?

TMJ is diagnosed more frequently in certain demographic groups. The National Institute of Dental and Craniofacial Research (NIDCR) of the National Institutes of Health reports that there are over 10 million people in the US who have symptoms of TMJ problems at any given time. A large majority are females between the ages of puberty and menopause.

The greater prevalence of TMJ problems in women during child-bearing years suggests a need for research examining the influence of gender-specific hormones on temporomandibular joint structure and function.

There is no information on the incidence of TMJ problems in various ethnic or racial groups.

We believe there are other physiological causes of TMJ conditions that have yet to be explored. It is important to remember that stress or mental health problems alone do not cause jaw joint diseases.

6. How long do TMJ problems last?

The type and severity of your symptoms may wax and wane from day to day. The available research indicates that most patients will get better with or without treatment. However, others can experience a lifetime of TMJ-related suffering and disability. People with TMJ diseases may have agonizing symptoms and experience frustration because their jaw problems are not fully understood by the scientific community or clinical professionals at the present time.