TMJ, or disorders of the Temporomandibular Joint, is a common set of conditions in the U.S. Symptoms of TMJ disorders are pain in the jaw, lack of mobility in the jaw, hearing a “click” or other kind of noise when you move your jaw muscles, headaches or migraines, and muscle stiffness.
We may refer to TMJ disorder as though it were one disease, but we now consider it to be a “family” of different conditions that have different causes and all affect the Temporomandibular Joint differently.
Most cases of TMJ are believed to be acquired. Accidents or falls that caused jaw injuries, dental procedures, wear and tear on the joints and muscles of the jaw due to age and disease are common causes of TMJ. Other times, patients can experience the symptoms of TMJ disorder with no obvious cause. This subset of TMJ disorder cases are believed to be genetic.
For a long time, researchers and professionals have believed that certain forms of TMJ dysfunction are genetic. If in fact TMJ is genetic, that means it can be passed down from family members into each new generation. Which cases of TMJ and what aspects of the disorder are genetic is still a controversial debate among health professionals.
Even if TMJ dysfunction itself is not inherited or genetic, certain risk factors for TMJ conditions have proven to be inherited through genetics. Here are the factors that researchers are exploring to see how much of TMJ dysfunction is in the genetics.
TMJ disorders and symptoms occur because the bite in your jaw and teeth does not come together in the correct way. The anatomy of the temporomandibular joint and the surrounding muscles and ligaments, as well as the jaw bones and teeth is believed to be in the genes from the time of birth.
A complex set of genes must work together at the right time during pregnancy to ensure the correct structure of the head, mouth, and jaw. It is believed that if there is an error in how these genes are formed and expressed, one might be at risk for TMJ dysfunction. However, what happens in patients with TMJ on the molecular and cellular level as well as their exact genetic makeup is not yet understood.
Also inherited is the position and shape of one’s teeth. People with teeth larger or smaller than normal, crooked teeth, or teeth out of the correct position are at high risk for TMJ dysfunction.
This is a new field of science that started in the 1990’s. Epigenetics is the study of how environmental factors interact with a person’s genetic makeup. Some scientists believe that genes for certain medical conditions can be turned on or off based on what happens in your external environment.
Following this logic, if you have a set of genes that predisposes you for TMJ dysfunction, it is quite possible you would never develop the condition at all. Or you could be predisposed to the condition and something in your environment as simple as excess stress could trigger the start of your symptoms of TMJ.
People with TMJ dysfunction are more likely to also suffer from one or more other chronic conditions, such as depression, anxiety, chronic fatigue syndrome, fibromyalgia, arthritis, or even irritable bowel syndrome. Almost all of these conditions are more prevalent in women and have a strong, proven genetic component.
You can develop one of these conditions, and then later experience symptoms of another. Or, you might even have a sudden onset of symptoms of TMJ dysfunction along with another chronic illness at the same time.
A few possible reasons exist for why TMJ dysfunction co-exists with other disorders. One reason simply might be that the individual is more susceptible to chronic pain. They might feel pain more deeply than others do. Therefore, TMJ dysfunction is more likely to occur.
Another common theory for co-occurring conditions is that one condition might lead to a specific behavior that causes TMJ. For example, if you suffer from any kind of chronic pain or feel anxious, you might grind your teeth and tighten your jaw muscles. If you have a habit of doing this throughout the day, you put too much stress on the muscles and joints around your jaw, leading to TMJ.
The more we understand what factors, both genetic and environmental, lead to TMJ dysfunction, the closer we are to more effective treatments. An understanding of each individual’s genetic makeup will allow health care professionals to predict who might be at risk for TMJ and provide appropriate treatment before the disease progresses. The right treatment for each individual will improve their quality of life.