THE EDITOR'S CORNER

Most orthodontists accept the idea that orthodontists may put teeth where they think they belong, and Nature overrules that during a settling process after restraints are removed; and that teeth do change position as time goes by. Thus, it has generally been considered futile to spend a great deal of time and effort on precision finishing of cases; "just get the teeth in the ballpark, and let them settle to where Nature wants them to be" There has probably been a 20% spread in the quality of the finished result on cases treated to those principles, depending on the skill and determination of the practitioner. The question is increasingly being asked--"Are those treatment goals adequate, especially for patients with temporomandibular joint problems?"

In the past, joint pain was considered to be not primarily related to the occlusion and few orthodontists were involved in its treatment. Those who were used splints, equilibration, centering exercises, and referral to other professionals. These patients wound up in pain clinics; and in the offices of physicians and dentists of all varieties, and chiropractors, physical therapists, and faith healers. Treatments included a wide assortment of drug therapies, injection of the joint with anesthetics and sclerosing agents, and full mouth rehabilitation. Recently we have seen added to these, sophisticated joint surgery, acupuncture, hypnosis, biofeedback, kinesiology, and a host of holistic cures. One characteristic of all of these is that they treat overt symptoms, primarily pain.

Clinical and laboratory research by orthodontists and others, principally with a gnathological orientation, is presenting us today with nagging questions--Is the most appropriate approach to temporomandibular joint problems for orthodontists to treat the symptoms when they become severe? Or is it more appropriate for orthodontists to attempt to prevent TMJ problems? Is this best accomplished by treating patients as close as possible to an ideal functional occlusion according to gnathological principles? And, is this the most appropriate treatment for patients who already have symptoms; or additionally for those who have no symptoms, but signs of incipient or potential problems; or for all orthodontic patients?

These questions have sorted out patients into three categories: those with symptoms that they are aware of and can tell you about, such as pain, clicking, and other joint noises; those with no symptoms, but signs which examination can reveal--such as occlusal interference, occlusal wear, mandibular shift, slide, muscle soreness on palpation, and crepitus--which may indicate potential TMJ problems; and those with neither signs nor symptoms.

Orthodontists like Roth and Williamson, who have a great deal of experience with finishing orthodontic cases to gnathologic principles, are convinced that this is the best approach to function, stability, and prevention of TMJ problems; and a must for those patients with TMJ problems. Other orthodontists, most of whom have not treated to gnathologic goals, contend that we are dealing with a very adaptable system, with great margin for error, and that it is unreasonable to "overtreat" everyone in an effort to prevent symptoms that may appear in a minority of patients. They feel it is time enough to treat the symptoms when they occur. What is a reasonable resolution of this seeming conflict?

For the patient with symptoms, the role of the orthodontist is to perform a differential diagnosis and rule out, if possible, pathology within the joint. Of the courses then available, the repositioning splint advocated by Roth (JCO, February 1981) and Williamson (this issue) seems to be an appropriate first step. Other approaches may relieve symptoms; for example, as the factor of stress is reduced, symptoms may subside. Such approaches may not be wrong, or even inappropriate. The appeal of the use of the repositioning splint is that patients who can be stabilized on a repositioning splint likely have an occlusal factor that can be treated, while those who cannot be stabilized on a repositioning splint should probably be referred elsewhere. Moreover, the splint entails a technique with which orthodontists should be comfortable; and for the majority of patients who can be stabilized on the splint, an orthodontic treatment would be indicated, whose goals would be the correction of a demonstrable discrepancy in tooth and jaw relationships. This might have the potential of a more lasting result.

Orthodontists who choose not to practice a gnathologic approach to treatment have the option of treating patients with symptoms by using any of the numerous palliative or corrective methods, or referring them to other professionals. But, what about the patients who present for orthodontic treatment who do not have symptoms, but do have signs? As more adults seek orthodontic treatment, this may be a growing portion of many practices. The number of patients in a practice with signs of potential TMJ problems is directly proportional to whether and to what extent the orthodontist is examining for them. Orthodontists whose routine includes a systematic examination for these signs find them in 30% and more of the patients examined. Those who do not examine for them, never see them. But, seen or unseen, how important are these signs and what, if anything should an orthodontist be doing about them? If you re-read the list of signs, you would not think that they were good things. You would have to think that a person would be better off without them, and that many patients with such signs will eventually have enough wear and tear to develop symptoms. The problem is that you can't select those who will develop symptoms and those who will not--at least not so far. Since you cannot distinguish between the two, which way do you go? Do you treat all of them preventively, with no assurance that you will prevent the appearance of symptoms in a given individual? Or do you treat none of them preventively, with a reasonable assurance that some of them will develop symptoms?

For patients with signs, but no symptoms, if no orthodontic treatment is contemplated, the answer probably is that you treat none; or, at most, prophylactically adjust obvious occlusal interferences. However, if you are intervening orthodontically, is there not--on the basis of the evidence we do have--a case for designing the orthodontic correction according to principles that have at least a potential to prevent deepening signs of TMJ dysfunction or to prevent converting signs to symptoms? And, for patients who present for orthodontic treatment with neither signs nor symptoms, would it not seem logical to follow that same course?

There is no universal acceptance of where centric relation is, or how to find it, or what instrumentation to use, or even if centric relation is the best intercuspal position. Still, it seems wise to try to achieve a balanced position, somewhere in the neighborhood of centric relation. The system might be looked upon as a machine which ideally has its parts in alignment, and works best and quietest when it does. Recognizing that we are not dealing with a machine--in fact, we are dealing with an often imperfect system anatomically, physiologically, and functionally--it nevertheless seems reasonable to try for CO as close to CRO as possible as a treatment goal, rather than place added stress on the adaptability of the system. Orthodontists who cannot accept gnathology in orthodontics on the basis of present evidence, nevertheless owe it to themselves and their patients to know what that evidence is and keep an open mind as additional evidence is presented.