The Connection Between TMJ and Chronic Pain
Did you know TMJ/TMD shares common traits with other diseases? Following we will explore the function and dysfunction of this small joint that creates such force and wreaks havoc in the lives of an estimated 20 million Americans.
What is TMJ and TMD?
Our temporomandibular joint (TMJ) is formed where ligaments attach our temporal bone to our jawbone (mandible). And, with the help of muscles, tendons, and facial nerves, the TMJ allows us talk, chew, bite, swallow, yawn, burp, and more. Temporomandibular joint disorder (TMD) is any disorder or derangement that interferes with normal operation of the joint.
Things that can interfere with joint function include:
Misalignment of teeth.
Muscle dysfunction, such as myofascial trigger points (TrPs).
Overuse or repetitive motion - such as, teeth grinding, clenching with heavy lifting, or emotional stress.
Nerves – facial nerves entrapped by TrPs in the muscles. And, diseases that affect facial nerves, such as Parkinson’s or Multiple Sclerosis.
TMD as a chronic pain disorder
Research tells us TMD may either cause or share a similar mechanism in the brain with sleep problems and other chronic pain disorders. And, though more research is indicated the intensity of TMD pain may be due hypersensitivity caused by centralization.
The National Institute of Dental and Craniofacial Research (NIDCR) says TMD shares similar underlying mechanisms with certain disorders, and sleep, which is centrally orchestrated by the brain. Researchers, Park and Chung (2016), found, patients with TMD, especially those with high disability, had elevated plasma cytokine levels and increased scores for sleepiness and sleep quality, suggesting a correlation between TMD and sleep disturbance. Another recent study by Sanders, AE, et al. (2016), "Subjective Sleep Quality Deteriorates Before Development of Painful Temporomandibular Disorder, suggests “sleep quality deteriorates progressively before the onset of painful TMD”, therefore poor sleep is probably a better indicator and predictor of the onset of pain. Also important to note is that obstructive sleep may be affected by TMD.
Other problems that originate in the central nervous system, specifically the brain, have been associated with TMD. For instance, in a study by Dahan, H., et al., (2015) they looked for comorbidities associated with increased levels of TMD pain intensity and duration. The greatest intensity and duration of TMD pain was found in the migraine and chronic fatigue syndrome group. This is not surprising, because others report, “the concomitant presence of TMD and migraine may be related to intensification of central sensitization”.
What this means is that there may be a specific reason TMD is associated with certain disorders associated with centralization, such as fibromyalgia, sleep problems, ME/CFS, chronic headaches, irritable bowel syndrome, back pain, genital symptoms, PTSD, chronic pelvic pain, heart arrhythmias, allergy, etc. And, intensity may affect centralization and centralization may affect intensity.
TMD is considered a complex disorder and so is treatment. Management of TMD varies depending on the cause.
Conservative treatments include:
A mouth guard or joint stabilizer (customized is suggested to prevent unwanted permanent changes).
Eating foods that don’t require excessive or forceful chewing.
Avoidance of extreme stretching and repetitive motion, such as chewing gum.
Medications for inflammation, muscle relaxation, or anxiety.
Treatment of sleep problems.
Relaxation techniques, such as putting your tongue on the roof of your mouth.
Massage by putting your thumb in your mouth and fingers on the outside and gently rubbing the muscles.
Exercises recommended by a qualified provider.
Though not FDA approved yet, Botox® is being studied for the treatment of TMD.
While managing aggravating factors, and using conservative, reversible, measures are the first option; some cases of TMD may require arthroscopy, a scope that looks inside the joint and so the surgeon can make repairs. In the most severe cases, and with careful consideration, joint replacement by a maxillofacial surgeon might be suggested.
There isn’t a standard test for TMD, so our healthcare providers must rely on what we tell them about our symptoms and our history. In some cases, it may require a team of doctors, but the goal is always the same, improve function and quality of life. If you suspect you have TMD or you are experiencing changes, be sure to discuss them with your doctor.
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