THE EDITOR'S CORNER

Relapse is one of those key words in orthodontics. It is one of the governors of orthodontic treatment. Yet, we could make a long list of reasons why teeth may relapse. These include:

In spite of this impressive list, many orthodontists believe that they can prevent relapse by establishing favorable occlusal relationships; by placing the teeth in harmony with the environment of lips, cheeks and tongue; by elimination of pernicious oral habits; and by retaining while tissues rebuild to conform to the new positions of the teeth. In search of stability we have lived by the stricture of the full complement and we have marched under the banner of four bicuspid extraction. Advocates of various techniques have suggested that theirs contributed more to stability than others.

In an effort to get at this problem, first we should define our terms. Stability is firmness in position, permanence of orthodontic result. Relapse is return to a former state. What we are really talking about in orthodontics is not so often a return to a former state, as an instability of result. And I would guess that that instability is most often manifest as irregularity of the lower anterior teeth, tendency to revert to a Class II relationship, and upper anterior diastema.

If these were isolated and subjected to controlled research, the chances are that we could learn something more than we know now. For our present state of knowledge we seem to have more control over the movement of teeth and little control over growth or the physiologic environment which may be crucial to stability.

Even if orthodontic retainers are the tools of ignorance, they are, in the absence of any other control, a satisfaction to the orthodontist and the patient at least in terms of esthetics. After that, how much retention on the one hand or instability on the other hand will be accepted becomes an individual matter for the orthodontist and his patient.

I do not believe that prolonged retention is justified to satisfy the orthodontist or to build his collection of nice looking models. Prolonged retention is justified to satisfy the patient, in the absence of any evidence that such prolonged retention may be detrimental in some way. It could also be justified if it could be shown that it contributes to eventual stability. Or if it could be shown how much more healthful straightness may be than various degrees of irregularity.

My own guide to length of retention is to decide, after observing the results of gradual reduction of retention control, in those cases that are unstable what percentage of irregularity will occur, how unesthetic or unhealthful will that be, can a percentage of that be masked by coronal reshaping or by restoration? The patient and I then decide together whether retention should continue or be discontinued. However, the amount and the nature of instability that I see is such that I advise against lifetime retention almost 100% of the time.