Degenerative Joint Disease
Degenerative joint diseases (DJD) are processes in which the main features are degeneration of the joint bones and pain. There are various types of DJD. We like to separate them into two large categories, arthritis and resorptive processes.
The most common form of arthritis to affect the TMJ is osteoarthritis (OA). Osteoarthritis mostly affects cartilage, the hard but slippery tissue that covers the ends of bones where they meet to form a joint. Healthy cartilage allows bones to glide over one another. It also absorbs energy from the shock of physical movement. In osteoarthritis, the surface layer of cartilage breaks and wears away. This allows bones under the cartilage to rub together, causing pain, swelling, and loss of motion of the joint. Over time, the joint may lose its normal shape. Also, small deposits of bone—called osteophytes or bone spurs—may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint. Unlike some other forms of arthritis, such as rheumatoid arthritis, osteoarthritis affects only joint function. It does not affect skin tissue, the lungs, the eyes, or the blood vessels.
A Healthy Joint A Joint With Severe Osteoarthritis
Osteoarthritis may result from minor repetitive trauma, major trauma, infection, surgery, and metabolic abnormalities. The effects of OA are typically pain, limited motion of the jaw, and deviation of the jaw to the affected side when opening. As opposed to internal derangement where individuals will report popping or clicking, OA typically presents with crunching or grating sounds. Many times the OA will be localized to the TMJ and not present in other joints of the body. Radiology studies will reveal a degradation of the bony surfaces. OA most commonly affects women in their 30’s and 40’s. OA in the TMJ tends to “burn out” with time into a state of remission.
Treatment of osteoarthritis of the TMJ begins with non invasive treatments, however corticosteroid injections and minimally invasive procedures may become necessary to reduce discomfort and improve function. Occasionally surgery is required to remove loose fragments of bone and reshape the bone surfaces.
Rheumatoid arthritis (RA) is an inflammatory disease that causes pain, swelling, stiffness, and loss of function in the joints. It occurs when the immune system, which normally defends the body from invading organisms, turns its attack against the membrane lining the joints. Scientists estimate about 1.5 million people, or about 0.6 percent of the U.S. adult population, have rheumatoid arthritis. Like some other forms of arthritis, rheumatoid arthritis occurs much more frequently in women than in men. About two to three times as many women as men have the disease. The TMJ joints may become affected by RA, typically late in the course of the disease.
Rheumatoid arthritis has several features that make it different from other kinds of arthritis. For example, rheumatoid arthritis generally occurs in a symmetrical pattern, meaning that if one knee or hand is involved, the other one also is. The disease often affects the wrist joints and the finger joints closest to the hand. It can also affect other parts of the body besides the joints. In addition, people with rheumatoid arthritis may have fatigue, occasional fevers, and a loss of energy.
Like many other rheumatic diseases, rheumatoid arthritis is an autoimmune disease (auto means self), so called because a person’s immune system, which normally helps protect the body from infection and disease, attacks joint tissues for unknown reasons. White blood cells, the agents of the immune system, travel to the synovium and cause inflammation (synovitis), characterized by warmth, redness, swelling, and pain – typical symptoms of rheumatoid arthritis.
The joint capsule is lined with a type of tissue called synovium, which produces synovial fluid that lubricates and nourishes joint tissues. In rheumatoid arthritis, the synovium becomes inflamed, causing warmth, redness, swelling, and pain. As the disease progresses, the inflamed synovium invades and damages the cartilage and bone of the joint. Surrounding muscles, ligaments, and tendons become weakened. Rheumatoid arthritis also can cause more generalized bone loss that may lead to osteoporosis (fragile bones that are prone to fracture).
A diagnosis of RA is typically made by an individuals primary care doctor or rheumatologist. Referral to a TMJ expert typically occurs when pain and dysfunction of the TMJ are not controllable with standard medical treatments. Treatment typically begins with conservative treatments, however eventually surgical treatments may become necessary.
Juvenile Rheumatoid Arthritis
Juvenile rheumatoid arthritis (JRA) is similar to rheumatoid arthritis but presents in children younger than 16 years of age. It is similar to rheumatoid arthritis but not exactly the same. 50% of children with JRA present with pain, swelling, or decreased functioning of the TMJ. In addition, there can be significant associated growth restriction of one or both TMJ resulting in facial abnormalities and possibly a fusing of the jaw joints referred to as ankylosis. The process in the TMJ tends to “burn itself out” and enter a state of remission over time. Therefore, we encourage conservative treatment during the active phases, however sometimes it is necessary to intervene with surgical procedures during the active phases. Once the JRA has burned out the resultant growth abnormalities will be evaluated and we can discuss potential jaw reconstructive procedures if indicated.
Idiopathic Condylar Resorption
Idiopathic condylar resorption (ICR) is a process in which the condyles of the mandible (lower jaw) partially resorb without any identifiable reason. This process causes shortening of one or both sides of the mandible resulting in jaw and facial abnormalities similar to those associated with juvenile rheumatoid arthritis. Most often ICR affects females age 15 to 35 years and is more frequent in teenage females during their growth spurt. In contrast to juvenile rheumatoid arthritis, affected individuals have generally good TMJ function without significant limitation in vertical opening or disabling pain. The diagnosis is one of exclusion, only after a complete work-up for local and systemic joint disease has returned no other diagnosis, can a diagnosis of ICR and be made.
Once the diagnosis of ICR is made, splint therapy to reposition the condyles in the TMJ may be helpful to prevent progression or at least relieve discomfort and muscle hyperactivity. We feel it is best to postpone definitive treatment until the condylar resorption has “burnt out.” If indicated, corrective jaw surgery is more likely to be successful if IRC has been stable for at least 1 year before treatment. Specialized bone scans can be utilized to determine if the ICR is still active or has “burnt out”. We believe the need to replace the joint is rarely indicated. However, jaw reconstruction and repositioning surgery is commonly necessary
As with any complex facial issues a team with TMJ and jaw reconstruction experts is essential to achieve optimal results.
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Posnick J, Fantuzzo J. Idiopathic Condylar Resorption: Current Clinical Perspectives. J Oral Maxillofac Surg 65:1617-1623, 2007