22 Sep עופר איתן Announces: The complexities of temporomandibular disorder
As hygienists, family and friends often ask us teeth-related questions. What toothbrush should I use? What do you think of this area in my mouth? Who is a good dentist in the area? Recently, a friend told me that her 20-something-year-old daughter was having “jaw pain,” and wanted to know what she should do about it. Should she see a dentist or a medical doctor? This simple question brought back memories of when I first was diagnosed with TMD and the search I undertook to discover more about my condition and subsequent treatment.
Our dental hygiene education teaches us about anatomy and physiology, the structures of the head and neck, and the muscles of mastication. We learn that the temporomandibular joint is composed of the mandibular condyle, situated in the mandibular fossa in the posterior articular eminence and in the middle of the articular disk, where it can be best suited for articulation. Any deviation of the positioning can result in temporomandibular pain and dysfunction known as temporomandibular disorder (TMD). Yet, we may know only the basics about TMD when asked by patients or friends.
Causes of TMD
TMD is caused by a variety of factors, have a variety of signs and symptoms, and there is no one specific cause or treatment for the disorder. TMD can be caused by problems with the structure of the anatomical joint, the muscles of mastication, or head/neck muscles. Depending on the actual diagnosis, treatments vary considerably. The National Institute of Dental and Craniofacial Research classifies TMD by the following:1
- Myofascial pain. This is the most common form of TMD. It results in discomfort or pain in the fascia and muscles of mastication or that control neck and shoulder function.
- Internal derangement of the joint. This involves a dislocated jaw or displaced disk (meniscus) or injury to the condyle.
- Degenerative joint disease. This includes osteoarthritis or rheumatoid arthritis in the jaw joint.
A TMD patient can exhibit one or several of the classifications at any time.
The actual cause of TMD may not be evident. Bruxism is often a cause but it is not exclusive. Trauma to the jaw, head, or neck, or postural and airway considerations are also factors. Arthritis and other autoimmune disorders have been implicated. A study by the National Institute of Dental and Craniofacial Research identified clinical, psychological, sensory, genetic, and nervous system factors that can put a person at higher risk of developing chronic TMD.1 In my TMD journey, I will never know what truly caused my disorder.
Approximately 35 million people in the United States have some form of TMD, yet not all should seek treatment for the disorder. The predominant patient population is women in their childbearing years, although many men and older/younger patients exhibit signs and symptoms. Due to the majority of women seen as TMD patients, there are numerous research initiatives focusing on the role female sex hormones, particularly estrogen, play in TMD.2 During my experiences, I noticed estrogen playing a role in the pain cycle.
Symptoms of TMD
Symptoms of TMD vary widely. Pain can be described as dull and achy or sharp and shooting. It can come from in front of the ear or along the muscles. Some patients experience no pain, but have limited range of motion (ROM). Symptoms can include but are not limited to:
- Pain in muscles of mastication or neck and shoulder areas
- Chronic headaches
- Limited movement or locking of jaw
- Ear pain, pressure, fullness, or tinnitus
- Clicking, popping, grating noise during jaw movement
- A bite that feels “off”
- Dizziness and vision problems
For patients who complain of limited ROM or locking, there are several possibilities. An internal derangement (ID) with reduction occurs when the meniscus is out of place when the patient’s jaw is in the closed position; upon opening, the meniscus goes into a natural position and then, upon closing, goes back abnormally. Often a click or popping sound will be heard during movement. An internal derangement without reduction occurs when the meniscus is out of position at closure and remains out of position during jaw movement. Patients exhibiting ID without reduction may have limited range of motion and an inability to open wide. Internal derangements are classified as early to late stage disease depending on a variety of diagnostic criteria including positive radiographic and imaging findings.
Patients may also exhibit limited opening but do not have internal derangements. These patients present with myofascial pain dysfunction (MPD) involving the muscles of mastication and/or head and upper body musculature. Patients with MPD will also have limited ROM, ear pain/tinnitus, pain on jaw movement, but will present with lack of radiographic evidence of bone or disk displacement. Patients can present with either MPD or ID with or without reduction or may exhibit signs and symptoms of both. I had both MPD and internal derangement without reduction.
There are various diagnostic tools used to evaluate TMD. Evaluating a patient’s ROM both in straight line opening and in lateral excursive movements while palpating the joint and muscles during an intra-/extraoral evaluation is critical. Note any popping or clicking during palpation along with any tightness or trigger point in the muscles. An adult should have a normal opening of 40-60 mm or three fingers’ width of opening with a lateral excursive movement of 10-15 mm. Observing any deviations on opening is also important. My maximum opening is 25 mm with a deviation to the right and lateral movement of 5 mm following all of my treatments.
Beyond clinical observations there are radiographic and imaging modalities that can be utilized. Panoramic, cephalometric, conventional tomography (CT), cone beam computed tomography (CBCT), or magnetic resonance imaging (MRI) can provide valuable information depending on the area imaged and the information requested. MRI, with or without contrast, is considered the gold standard of TMJ imaging.3 Imaging can be useful in determining disk position and function in both open and closed positions. Panoramic, cephalometric, and CT imaging are best for hard tissue examination, while MRI and arthrography can be used for both hard and soft tissue evaluation.4 I had panoramic, tomography, and MRI images of my joints and the diagnosis was inconclusive.
Beyond clinical observations and imaging diagnostic tools, products designed to measure bite analysis, TMJ Doppler auscultation, electromyography, TENS (transcutaneous nerve stimulation), joint or muscle injections, Botox treatments, laboratory testing, and behavioral assessments can be used for either diagnostic or treatment modalities. As diagnostic tools, any of these can assist in determining if an internal derangement or MPD exists, while a few can be used to alleviate pain and limited ROM. I have experienced all of these with the exception of Botox either as treatments or diagnostic tools during my TMD journey.
The goal of any TMD treatment is to provide good function and a relatively pain-free existence with friction-free movement. There are myriad treatments available for TMD depending on whether the involvement is structural or muscular. Approximately 90% of patients can be treated successfully with nonsurgical interventions, while 10% will eventually need surgery. I am one of the 10 percenters.
Nonsurgical treatments should commence for a minimum of two to three months with a maximum of one year of treatment unless there are definitive osseous changes noted during the treatment. Due to the nature of TMD, treatments less than two to three months of treatment are often not sufficient in length to provide long-term relief. Treatment goals center around restoring normal joint mobility and restoring normal body balance, and two to three months are required to obtain these goals.
Initially, a soft diet is recommended with heat or ice treatments to either the joint or muscles as appropriate. Physical therapy treatment and exercises may be recommended. Analgesics such as NSAIDS or muscle relaxants may also be prescribed. There is controversy regarding the use of opioid medications due to the potential for addiction, and these should be used only in consultation with the patient’s physician.5
Many patients find relief by using balanced oral appliances. TMD appliances range from maxillary only, mandibular only, both maxillary and mandibular combined, or a nociceptive trigeminal inhibition device (NTI). An NTI device is an anterior bite stop that is indicated for the prevention of bruxism, TMD, tension-type headaches, and migraines.6 The specific TMD diagnosis and the practitioner’s philosophy of treatment will determine the type of appliance the patient receives. No one type of appliance has been proven to be more effective than others for all patients. I have experienced maxillary, mandibular, NTI, and combination appliances.
Since there is an emergent body of evidence that suggests correlation of obstructive sleep apnea with chronic pain disorders, including TMD,7 it is recommended to evaluate all TMD patients for OSA and treat appropriately with noninvasive therapies.
When conservative treatments are not successful, more invasive options must be considered. Although considered conservative, the use of low-level laser therapy has shown mixed results in a variety of studies.8 Muscle and joint injections with Botox, anesthetics, or steroids can be utilized as part of increasingly invasive treatment protocols.
The final treatments involve surgical options. These include arthrocentesis, arthroscopic surgery, or full open-joint surgery and joint replacement. Arthrocentesis is a minimally invasive surgical procedure that relieves joint stiffness from fluid buildup while reducing inflammation or allows for disk repositioning. For TMJ arthrocentesis, an oral surgeon will administer either IV sedation or general or…