On New Years Eve, Australian rapper Iggy Azalea shared with her Twitter followers that she was diagnosed with a temporomandibular joint dysfunction (often referred to as TMD or TMJ). The singer is among the estimated 10 million Americans who suffer from the condition, which is more common in women than men and people ages 20 to 40.
Symptoms of the disorder include a stiffness of jaw muscles, limited movement, clicking or locking of the jaw and radiating facial pain. It was previously believed that problems with how the teeth fit together or the structure of the jaw caused the condition. But in talking to Michele Jehenson, DDS, a clinical assistant professor at the Pain Management Center at Stanford, I was told, "There is still a lot we do not know about what causes [temporomandibular joint dysfunction] but one thing we do know is that they are not caused by upper and lower teeth misalignment or improper jaw position. We now believe that TMD susceptibility is, at least, partly genetic."
Since the causes of the TMD are not clear, diagnosing the condition can be challenging. Currently, there is no standardize test for providers to use to diagnose patients, so physicians continue to rely on the clinical evaluation, including palpation, range of motion and auscultation. But imaging technologies are starting to play a more important role. Jehenson noted, "We now have more accurate imaging such as cone beam CT scans or MRIs. Some dentists use joint vibration analysis or EMG, but these electronic sensors have been shown to be unreliable and lead to over diagnosis."
Over the past two decades, there as been a significant amount of research on the outcomes of TMD treatments. As Jehenson told me:
Evidence is very clear that aggressive and non-reversible treatments for TMD (braces, jaw surgery, crowns, full time wear of appliance, jaw repositioning) are rarely indicated. The best treatments should be conservative. Depending on the case, treatments are usually a mix of medication (oral or topical), nighttime appliance wear, injections, physical therapies, behavior modification and counseling, sleep and stress management.
To learn more about the diagnosis and treatment of TMD, join Jehenson for a Stanford Health Library talk on Thursday at 7 PM Pacific Time. During the event, she'll l further discuss evidence based versus non-evidence based treatments. Those unable to attend in person can watch the talk online.
Photo by Eric Allix Rogers