Temporomandibular joint dysfunction (TMD): Chiropractic approaches to temporomandibular joint dysfunction (TMD)
Twenty-five years ago, chiropractors knew little about temporomandibular joint dysfunction (TMD). They weren’t alone. Medical doctors and dentists were equally unfamiliar with the disorder. Darryl Curl, DDS, DC, recalls those early years and shares personal stories that read like a timeline on the understanding and treatment of TMD.
It all started not long after he graduated from the University of California/San Francisco School of Dentistry in 1976. A patient asked him if he treated TMD. “And I remember sitting there in silence thinking, `TM-what?.’ Dr. Curl says. “From that point forward, I promised myself I would not be stumped on this subject again. I took seminars, bought books, and studied everything I could get my hands on.”
Over the next ten years, dentistry would begin to address the subject in its schools, research, and practices. Dr. Curl continued to pursue his own interest in TMD, devoting more than 2,000 hours to its study. So when his patient, Rick, came in with TMD, he was ready. Or so he thought.
“I made him a mouth splint and told him to come back in three weeks. He didn’t come back for six weeks, but when he did, he came strolling into the office with a smile on his face. He showed me how his jaw moved straight up and down and didn’t click anymore, and I was beaming from ear to ear. I had only seen him that one time and now he was so much better. I asked him how long he had to wear the splint before he got better, and he just looked at me. ‘Heck, I didn’t wear the splint hardly at all,’ he said. ‘I went to my chiropractor, who said that one leg was shorter than the other by an inch. So he corrected my leg length, adjusted my neck and back, and look,
Doc, my jaw’s fixed!’ As he told me more, I felt sick because I was indoctrinated in traditional medicine, and I just couldn’t understand. But he was living proof, standing right before me.” Dr. Curl visited with Rick’s chiropractor, who explained how leg-length discrepancy would essentially throw off all the joints in the body and muscle tone in the leg. “While what he was saying made sense,” he adds, “I was confused because nowhere in my training had I been introduced to anything like this. After that, I actively sought out chiropractors and talked with them. And I found out something interesting. If I asked dentists in those days what they would like their children to do, most would say they didn’t want them to be dentists. But when I asked chiropractors, they said they would like their children to be chiropractors. That’s when a light went on in my head. ‘This is where I need to be,’ I said to myself. ‘Here is the answer to my prayers. I’ve been trying to invent the wheel, and it’s already been invented.”‘ Dr. Curl attended the Los Angeles College of Chiropractic (now Southern California University of Health Sciences), where he eventually served as full professor. He retired three years ago to go into private practice and currently teaches the orofacial pain residency program at UCLA. TMD is a collective term for a broad range of disorders displaying a variety of signs — radiating pain in the face, neck, or shoulders; limited movement or locking of the jaw; painful clicking or grating when opening or closing the mouth; and a significant change in the way the upper and lower teeth fit together. Symptoms can also include headaches, earaches, dizziness, hearing problems, and difficulty swallowing.
“There are combinations of symptoms with TMD. It’s a large topic, and even those at the National Institutes of Health agree there is no standard to diagnose this condition,” says Jason Flanagan, DC, who serves as dean of Academic Affairs at Texas Chiropractic College. “And there’s another catch. TMD symptoms can result from other areas of the body not only upper-cervical subluxations, but all the way down to the foot. If something were to happen to the medi al arch of the foot because of a stone bruise or trauma, that can cause the pelvis to torque and induce a functional scoliosis pattern of compensation in the spine that can cause problems all the way up to the temporomandibular joint.”
Moreover, many TMD symptoms can mimic other disorders in that general area, such as congenital malformations, some kinds of arthritis, infections, and tumors. And some symptoms of TMD are similar to common conditions that do not require treatment -occasional discomfort in the jaw joint or chewing muscles, for example, or non-painful jaw clicking. In order to deliver the best diagnosis and care, many DCs and dentists are teaming up through referrals and partnerships to more effectively diagnose and treat TMD.
Harvey Getzoff, DC, began co-treating patients with Albert Chinappi, DDS, in the early 1980s. Dr. Getzoff uses the sacro-occipital technique (SOT) for treatment of jaw and dental-related problems. SOT divides the body into three functional but interrelated categories: cranial sacral respiratory mechanism; weight-bearing body system; and lumbar spine and its supportive tissue.
“When I realized that the cranium was part of the structural system of the body, I then realized that the temporomandibular joint (TMJ) and the way the bite works are all involved in the same system,” he says. “Since then, Dr. Chinappi and I have spent years discussing, from the perspective of our own disciplines, the nature of TMD and the impact on the body. We find that some of the things that mimic TMD are facial pain, caused by cranial-sutural problems, and sometimes neck pain or upper-cervical pain problems. When you have a true TMJ structural problem, you almost always have cervical problems. The jaw is very related to the neck. The anterior muscles of the neck are the mandibular suppressors or depressors, so the muscles that bring the jaw down are the same muscles that bring the head down. In my opinion, it’s almost impossible not to have some kind of cervical problem when you have a TMJ problem.”
The TMJ is an atypical extremity joint. Most joints have two bones that come together and move against each other, staying within a reasonably close proximity through a full range of motion -not the TMJ. “If you fully open your mouth, it’s almost as though you partially dislocate it,” explains Christopher Good, DC, MA(Ed), CCSP “It’s one of the few joints that does that in the body.”
Severe injuries from macro-trauma as well as micro-trauma to the jaw are leading causes of TMD. For example, anything from a hit in the jaw during a sporting activity to overuse syndromes, such as chewing gum excessively or chewing on one side of the mouth too frequently, can cause TMD. Cervical spine hyperflexion-hyperextension injuries that tear soft tissues and ligaments and cause abnormal muscle tension in the neck and jaw can create changes that lead to TMD. In addition, both physical and emotional stress can lead to TMD; an example of physical stress is the once-common practice of sitting in a dentist’s chair for several hours with the mouth wide open. Dr. Curl reports that most dentists are now aware that this is defeterious to the jaw.
tists are now aware that this is deleterious to the jaw.
“They try to work, take a break, work again, take a break,” he explains. “They also screen patients to see if they have any weaknesses in the jaw structure that would seriously predispose them to physical injury if they keep their mouths open very long. In that case, they may use medications during the procedure to minimize the injury potential to the jaw, or they might send the patient to physical therapy immediately following treatment, In less severe cases, they instruct the patients on exercises they can do at home to loosen up the joint after being open for so long.”
While emotional stress itself is not usually a cause of TMD, its physical ramifications can be. When people are under psychological stress, they may clench their teeth, which can be a major factor in their TMD. “On the other hand, if they are not teeth clenchers, then their psychological stress is probably not a factor in TMD,” Dr. Good explains. “That’s why we cannot definitively say ‘never’ or ‘always,’ because the human condition is far more complex than that.
You can have one or two individuals out of 100 who have this unique scenario and who have this as the cause of their problem, but it may not be a factor for the other 98 people.”
Dr. Good serves on the faculty of New York Chiropractic College and has contributed to the textbook chiropractice Peripheral joint technique.
Women experience TMD four times more often than men. Several factors contribute to this higher ratio. Women experience what Dr. Flanagan calls 11 growth closure,” a natural occurrence in which the mandible widens and bone formation of the face occurs faster than in men. In addition, a variety or other factors, such as the sitting position at the workplace, general posture, and higher heels can contribute to increased symptoms of TMD.
Some conditions once accepted as causes of TMD are no longer considered viable by the NIH- moderate gum chewing, non-painful jaw clicking, orthodontic treatment (when it does not involve the prolonged opening of the mouth mentioned above), and malocclusion. Popular theory now holds that while these may be triggers for TMD, they are not causes.
“Jaw clicking is more of an effect,” explains Leonard Vernon, DC, an adjunct associate professor at the University of Bridgeport College of Chiropractic. “Ifyou have TMD,you may or may not have jaw clicking, depending on the disc that is over the joint itself. If it moves, it can move forward. And if it slips forward, then you’ll have that jaw clicking. But jaw clicking in and of itself does not mean that you have TMD. And likewise, not every TMD has jaw clicking.
According to the NIH, malocclusion presents a similar scenario. Many people have malocclusions but do not suffer TMD, while many people suf[bring TM[) do have malocclusionagain, an effect, not a cause. But
Dr. Getzoff disagrees.
“TMD is a malocclusion disorder. My experience is that malocclusion is the primary cause of TMJ problems. When diagnosing TMD, it is important to be able to make a dental diagnosis of the bite. Class I bite is a normal bite. There are a lot of criteria, but generally speaking, the upper teeth should overlap the bottom teeth by a millimeter or two, and there should be alignment of the central incisors, both upper and lower, as well as the canine teeth. There are three types of abnormal bites. Class II, Division One, is an overbite (overjet). Class II, Division Two, occurs when the upper front teeth retrude, that is, point backwards and hold the jaw back. Class Ill abnormal bite occurs when the teeth touch, edge to edge, or the bottom teeth are ahead of the upper teeth. The reason you make a dental diagnosis is because if there is a Class 11, Division One or Two, or a Class III bite, then there is a malocclusion and the chances are higher that you have a TMD.”
To help diagnose or rule out TMI), Dr. Flanagan reports that his colleagues ask their patients to put three lingers in their mouth and bite down on them. If they can do that comfortably, they probably have a normal tracking of the mandible. Patients are also asked to open and close their mouths and chew 26 times while the doctors monitor the dimension of the mandible and the balance of the muscles. “If they have no problems while doing these things, then the problem is not likely to be TMD,” Dr. Flanagan adds. “if the biomechanics are normal but they still have symptoms, then we start to suspect referral mechanisms.”
Dr. Good tests various structures during the examination and looks for signs of inflammation and for abnormalities, such as changes in the mandibular gait. “Only then can I start drawing conclusions as to what is causing the patient’s pain,” he says. “I rule out factors such as trigeminal neuralgia, which is an irritation to one of the cranial nerves that can cause pain over the region. There are any number of things that can cause pain to that region, so you have to play detective, ruling these things out. Sometimes you’ll need special imaging, an x-ray, or an MRI to help confirm the diagnosis.
Dr. Getzofl prefers to leave the imaging to the orthodontist, who has the proper equipment to achieve a panoramic view of the jaw. “It’s difficult on a chiropractic x-ray machine to image the jaw, because there is a lot of overlapping bone,” he explains. “Personally, I don’t need an x-ray. By performing an opening and closing of the jaw in a standing position, I can determine how much discrepancy and how much dysfunction are there.”
Dr. Vernon does order MRIs on occasion, but he finds that managed care has limited payment and increases paperwork to the point that it may not be worth it. “The only time I would insist upon an MRI is if someone had symptoms that dictated it-For example, if a patient is unable to open the mouth more than a few millimeters or if he or she is very symptomatic.
The treatment of TMD may include manual manipulation, massage of soft tissue, heat/ice, exercises, and patient education. In most cases, the first intention is to relieve symptoms, particularly pain.
“Chiropractic can play a key role in TMD when there are adhesions between the disc and the joint itself or the temporal bone,” explains
Dr. Flanagan. “Micro-adhesions restrict normal positioning of that disc in the joint. Manual manipulation allows for the proper forces to be applied, which gaps open that joint. The TMJ is a synovial joint, but it’s more fibrous in origin than other synovial joints. It allows the disc to go back to its normal position for normal tracking. Results have been very good.”
Dr. Getzoff has also achieved significant pain reduction related to TMD with cranial sutural adjusting. “The other approach is through some direct methods to get the TMJ to open more normally by guiding it through motion with light pressure at the angle of the mandible.” From the first visit, however,
Dr. Getzoff informs his patients that he cannot make the jaw function properly in the presence of malocclusion.
“I explain to my patients that we can work to get them to a point where they feel better. We can relieve the pain, and then see how satisfied they are at that level,” he says. “I’ll tell them, ‘That’s as far as we can get you.’ If they’re satisfied, that’s fine. If not, that’s when I send them to the orthodontist.”
Dr. Good considers soft-tissue work on the muscles of the region especially important because trigger points in the muscles of mastication are a great source of pain. When the joint becomes hyper-mobile and painful through macro-trauma or micro-trauma, the muscles start to guard the joint and tighten up.
“That creates this very curious phenomenon that can lead a doctor to think that the joint is actually hypomobile because the muscles are tight, when, in fact, the joint itself is too loose,” he explains. “If you then start manipulating that delicate joint because the muscles are stopping the motion of it-when the joint capsule itself is actually too loose -you could do more damage. We reserve manipulations for when there is clear evidence of the joint being locked up or restricted. We prefer to start with mobilization and trigger-point therapy. Less is more, because it’s a very sensitive joint area. I also like to use a muscle therapy known as active release technique (ART), which is an advanced form of soft-tissue work. Basically, you contact the muscle, and then pull the muscle underneath your contact, which is your thumb or your fingers. As you’re doing this, you’re stretching the tissue and breaking up the muscle contraction, as well as breaking up any adhesions in the muscle. This is commonly done on athletes who have chronic problems in their muscles. It can be quite painful, but is very effective.”
Teaching patients how to apply heat and ice, training them how to avoid harmful joint movements, and giving them TMD-specific exercises all help to complement clinical treatment. Ice is recommended during the acute and intermediate phases of healing.
Patients are counseled to switch to heat in the later stages of healing, especially if they are still experiencing discomfort. While good nutrition is important for every patient, dietary suggestions for TMD patients refer more to joint considerations than nutritional ones. For example, digging into a hard apple is just as deleterious as chomping down on candy. And giant sandwiches, no matter what the ingredients, can cause the mouth to open too wide and have a destabilizing effect on the jaw.
Exercises -both stretching to loosen and strengthening to tighten muscles -can help restore the mandibular gait. Special feedback sensors in the jaw-the same ones that allow us to learn how to chew without looking in a mirror-can be retrained.
“You can train a patient to only open so far, and eventually that sensor is activated at that distance,” Dr. Curl explains. “You can encourage the muscles to be tighter until the jaw joint tissues adapt and take over the stabilization function.’ The muscles need to tighten up and act as though they are a ligament part of the time. Then, give patients some exercises to keep the jaw muscles tight. These can he isometric, or you can use my favorite: chew gum for 10 minutes, six times a day. Patients say, ‘That’s too easy,’ or ‘I was told never to chew gum.’ Of course you can’t chew gum for hours on end, but I’m only assigning gum chewing as an exercise.” With the exception of “water-pack” and other guards against teeth grinding, many doctors prefer to refer TMD patients to dentists or orthodontists when appliances or splints are required. Dr. Vernon, for example, performs the soft-tissue and joint manipulations on the TMJ, while the dentist prescribes mandibular orthopedic repositioning appliances. “Together with the repositioning device or splint and the manipulations, sometimes aided by ultrasound to the joint and the muscles surrounding the joint, patients usually improve nicely,” he adds.
But, Dr. Getzoff cautions, make sure you understand the type of orthodonfist with whom you are working. Some pull teeth to achieve a Class I occlusion, while others prefer the use of function appliances to expand the upper arches and make more room for the mandible, followed by the use of braces to position teeth. “The difference is that when you pull out teeth, if the facial bones didn’t grow and develop properly, you’re setting them in by pulling out teeth,” he explains. “On the other hand, if you use these appliances to expand the bone, then you’re allowing the bones to develop and grow, and it gives more room for the jaw to properly posture itself so the jaw joint is more functional. A good analogy is if you have an overcrowded platform at a train station, you can either throw people off the platform or you can build a bigger platform. I prefer the latter. I work with orthodontics that develop the face and allow the head and jaw to position themselves better.”
And, Dr. Curl warns, not all dentists are sufficiently knowledgeable about appliances. “When patients come into my office wearing splints made by another dentist, I invariably take them off,” he says. “Too often that’s not the right therapy for their problem, but there’s a large body of dentistry dealing with TMD that is as convinced of the clinical effectiveness of splint therapy as it is of the existence of the moon. Of course, there are occasions where the splint is a sweet little treatment modality to help the patient through to the other side. If you twisted your ankle, and the ligaments and muscles in the ankle were quite sore, it makes sense to put an ankle brace around it for support. Dental splints can do the same thing, lessening the load on the jaw joint and allowing the joint to recover faster without the constant loading we do over and over again every day. The trouble is, problems caused by dental splints far outnumber the true cures achieved from dental splints. Think of it this way. If I hire a carpenter whose tool kit only includes a hammer and nail, he’s going to figure out how to use his hammer to fix my problem, whether that hammer is designed for the problem or not. Similarly, if I go into a dental office where they have a limited toolbox, and they’re all geared up for making splints, I get worried that they will probably give patients dental splints, whether they need them or not. On the other hand, if I go into a dentist’s office whose toolbox is rich in treatment options through training and understanding, then I don’t worry about that office using splints.” Like other neuromusculoskeletal disorders, many TMD problems are selflimiting and will heal themselves to a certain extent once patients stop moving the region. But, Dr. Good says, the problem is often not cured. Left untreated, it can lead to more permanent damage. “As patients resume activity in that area and stress the joint, it becomes symptomatic again,” he says. “Longterm, if you have mechanical dysfunction but you don’t get it treated, you are likely to make damaging changes that can develop into degenerative changes, which may then eventually cause you to seek surgical intervention.”
Monitoring outcomes is also critical. While chiropractic can achieve excellent results-often in a short period of time -once improvement slows or hits a plateau, it may be time to refer. “After you’ve worked on the patient for a fair length of time -one to two months -if you’re not seeing continuous improvement, then you’ve got to go to the next step and refer to a dental specialist, orthodontist, or myofascial surgeon,” Dr. Good adds. When considering treatment options, Dr. Curl urges doctors to keep the treatment simple. “Most chiropractors offer treatment that normalizes the load and synchronizes the muscle and joint movement patterns, and the cost of therapy in a chiropractor’s office is a fraction of that in a dental office. The bonus is, even if the chiropractic therapy doesn’t work, the patients are absolutely no worse off than they were when they stepped into that office. This isn’t necessarily true in a dental setting. I see patients leaving the dentist with three or four drugs and a $2,000 mouth guard. The price for only limited improvement can run as high as $10,000. Dentists will try to rebuild the entire mouthful of teeth, grinding them all down, putting on new crowns and braces. If patients remain in that treatment model, they are likely to end up in surgery, despite the fact that to date, we just don’t have any surgical procedure that will improve the average TMD patients predicament. I have treated patients who have had 8 to 12 surgeries to the joint. When these patients eventually make their way to you, you want to cry because you wish they had told the surgeon that one simple word-No.”‘ Recent reports from government agencies support the chiropractic philosophy that surgery and other permanent irreversible treatments should be considered as a last resort. Complications from artificial jaw-joint implants, for example, have led the Food and Drug Administration to recall certain implants. In addition, NIH web pages on TMD state, “Surgical treatments are often irreversible and should be avoided where possible…. Scientists have learned that certain irreversible treatments, such as surgical replacement of jaw joints with artificial implants, may cause severe pain and permanent jaw damage.”‘ Sometimes, of course, chiropractic is not effective in treating TMD. “I would say that chiropractic is least likely to be effective when the actual disc over the joint itself slips very far anterior and there is a disc problem in the joint itself,” Dr. Vernon says. “Chiropractic has only a 50/50 chance of helping at that point. Then, it becomes a dental case, and sometimes even a dental surgery case. Other than that, most of these people do respond to chiropractic care or the combination of chiropractic care and splinting.” The chiropractic profession’s training, experience, and philosophy are well suited to treating TMD, says
Dr. Good. “We are perfectly placed as chiropractors to treat TMD. We already are specialists in the neuromusculoskeletal system and specialists in joint dysfunction. We also have a good basis for knowing when to treat and when to refer musculoskeletal patients. We have a large number of therapeutic tools at our disposal. I believe that chiropractic is a great place for TMD patients to start.”
Research on TMD
Research on chiropractic care of TMD is still limited, with only a few studies reported in the literature. A series of studies involving the University of Iowa and Palmer Center for Chiropractic Research comparing the effectiveness of chiropractic treatment with medical treatment is being developed by James DeVocht, PhD, DC; Deb Zeitler, DDS, MS, professor and vice chair of the Department of Hospital Dentistry at the University of Iowa; and Wally Schaeffer, DC, a clinician in private practice. Cynthia Long, PhD, a statistician who works at Palmer, has guided the development of the methodologies of these studies, designed most of the forms and questionnaires the team is using, and will handle the analysis of the data.
Their process began with a preliminary inter- and intra-examiner reliability study. “It was a small, but formal, Institutional Review Board-approved study in which we examined how repeatable the maximum-mouth-opening-with-pain measurement was by both of the specific clinicians who will be making those measurements in this study,” Dr. De Vocht explains. “We had each clinician make two measurements on each of 24 subjects and found good repeatability-both when compared to their own measurements and when compared to the other’s measurements.”
Next, the team is set to begin an observational study of unsolicited patients of the clinic. “When they come in, they will be invited to participate in the study, which simply involves taking some additional information and making one physical measurement-how far they can open their mouths without pain,” Dr. DeVocht continues. “We were not comparing them or doing a randomization of patients, but simply observing how the treatment is conducted. We were also developing instruments to document that information both in the chiropractic and the hospital settings.” Their questionnaires include general demographic information and basic questions that are useful in the clinical setting. Specifically, the Jaw Symptom Questionnaire’, consists of the following questions: * Does it hurt when you open wide to yawn?
* Does it hurt when you chew or use the jaws?
* Does it hurt when you’re not chewing or using the jaws?
* Is your pain worse upon waking?
* Do you have pain in front of the ear, or earaches? * Do you have jaw muscle or cheek pain?
* Do you have pain in the temples?
* Do you have pain or soreness in the teeth?
e Do your jaws make noise so that it bothers you or others?
e Do you find it difficult to open your mouth wide?
* Does your jaw ever get stuck/lock as you open it?
* Does your jaw ever lock open so that you cannot close it?
* Is your bite uncomfortable? They also used a VAS (visual analog scale), a 10-centimeter line that represents the range of worst pain possible to no pain; participants are asked to draw a vertical line along that horizontal line to rate their current situation.
“The purpose of this phase is to find out what kind of patients are actually seen, whether these instruments will give us usable information, whether they are understandable by the patient, and if there are any problems with them,” Dr. De Vocht says. “We will then do a small pilot study of a randomized sample of about a dozen subjects. If the current study and the following randomized pilot study go well, we will then begin seeking federal funding for a full randomized control trial.” V
1. Chiropractic Perohem Joint Technique, edited by Raymond Broome, Butterworth Heinemann, 2000.
www. ndcrhih.gov/news/1pubs/tmd/sec6.htm. 3. Clark GT, Sanders B. Digna*tic Arthr.vpy of the Temporomandibular Joint, WB Saunder.4, 1989; p124.
Other resour www.tmj.org
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