First Things First
Shortly before he died, my friend and TMD mentor, Welden Bell, counseled a young oral surgeon who was having an unusually difficult time resolving a patient's TMD. The surgeon explained to Dr. Bell how he had decided to perform successive plications on the patient's TMJs without resolving her limited mobility, popping, and pain. In fact, all of the patient's symptoms and signs had increased with each surgery, and her pain was now constant and intractable. My young dental friend had clearly reached the end of his therapeutic rope.
In his characteristically kind but professionally confident manner, Dr. Bell said, "It sounds to me like you have had a little too much treatment and too little diagnosis." Without even trying, Dr. Bell had summed up the current state of TMD diagnosis and treatment.
In the past year, the general public has learned a great deal about the subject from magazines, newspapers, and talk shows. Dentists should hardly consider this increased knowledge to be salutary, because if they and their patients haven't yet reached the same conclusion as Dr. Bell, it seems clear they soon will.
An April article in the Wall Street Journal described how thousands of people have been terribly and often irreversibly harmed by aggressive TMD therapies, including Teflon implants that have fractured and left patients with inflammation, bone erosion, immune reactions, and incapacitating pain. So many people have suffered from dubious TMD therapy that they now have a large support group--the Milwaukee-based TMJ Associates, with 5,200 members.
Unfortunately, by training and patient expectation, dentists are primarily therapists, not diagnosticians. This simple fact goes a long way toward explaining why dentists respond so quickly to TMD complaints with therapy instead of diagnosis, and why they tend to treat such complaints in a parochial manner. If TMD patients happen to go to a prosthodontist, they will probably end up with some kind of bite alteration. If they visit an orthodontic office, they should probably get ready to spend some time in braces. And, of course, we all know what oral surgeons do for a living.
Much of the diagnostic confusion about TMD stems from fundamental misconceptions about the principles of joint physiology and anatomy that were accurately described long ago by Harry Sicher and have since been corroborated by a host of investigators, including Basmajian, McNamara, DuBrul, Bell, Okeson, Sarnat, and Mahan. It isn't a matter of lacking the information we need to make accurate diagnoses, but rather of failing to embrace the few solid principles we do have.
That situation probably won't be corrected until dentists develop as much interest in diagnosis as they have in delivering treatment. I know from personal experience that if you want to start a dental audience fidgeting or sleeping, just start talking about TMD diagnosis. Interest won't return until you begin to describe techniques for constructing splints or establishing new occlusal positions. Only the most dedicated teachers and audiences participate in discussions about TMJ anatomy, physiology, and, yes, diagnosis. But as Dr. Bell said, "There is no longer any valid reason for divisive, conflicting, and mutually exclusive concepts of what constitutes normal masticatory function. Purely empirical and trial-and-error therapy are no longer justifiable. Precise diagnosis and rational, predictable treatment methods can bring management of most TM disorders within the grasp of knowledgeable practitioners of dentistry."1
I suppose the most remarkable feature of overaggressive TMD therapy is that so many patients escape relatively free of permanent iatrogenic damage. This says a lot about the adaptability and self-healing capability of this unique joint, and we can all be thankful for it. Dr. John Dode, director of the New York chapter of the National Council Against Health Fraud, correctly noted in the Wall Street Journal article that given enough time and rest, most painful joints improve with little or no treatment. He advises dentists to proceed slowly and to let nature do its thing while using simple, reversible therapies that don't aggravate the situation, yet give the patient some relief from discomfort.
The drawback of this regenerative power is that many a dentist has been convinced that a particular mode of treatment healed a painful joint when, in fact, the joint improved in spite of the therapy. It brings to mind the Latin phrase, post hoc, ergo propter hoc--"after this, therefore because of this"--which is how many of our cherished beliefs and superstitions persist for centuries despite being wrong.
I hope you won't consider this a polemic against TMD therapy in general. Nothing brings more satisfaction to a health professional than successfully diagnosing and treating a painful human ailment, and I enjoy this part of dentistry as much as the next person. Certainly, surgical intervention has a legitimate place in our TMD armamentarium; indeed, for some anatomical abnormalities, we may have no alternative. But we need to remind ourselves every day that diagnosis should precede therapy and that if the diagnosis is wrong, any applied therapy runs a high risk of being inappropriate.
The longer I practice dentistry, the more convinced I become that most TMD maladies, except for those caused by trauma, are due to parafunctional habits--mostly carried out on an unconscious level. Therefore, anything we do to interrupt these habits improves the prospects for healing. Anterior repositioning splints succeed not because they "recapture the disc", but because they disengage the teeth and place the jaws in a position where patients can't possibly bite with maximum force and continue to injure themselves. Brackets and leveling wires often have a similar effect, not because we have suddenly placed the teeth into proper positions, but because we have made the teeth so sore that patients keep them apart, even unconsciously, to avoid the discomfort of full occlusion.
Dentists might be wise to exercise a little more modesty about their therapies and a little more caution about the more aggressive and irreversible ones. It might also help to recall another Latin phrase, primum no nocere--"first do no harm".