THE EDITOR'S CORNER

We talk about preventive orthodontics, but when it gets right down to it, we are hard put to describe too many orthodontic problems for which we have preventive measures to apply. We use up the subject of preventive orthodontics so quickly that we are talking about interceptive orthodontics before we know it.

Prevention is not permitting something to occur in the first place. If we maintain the space for a prematurely lost deciduous second molar until the permanent successor has a chance to erupt into normal position, we have prevented the mesial drift of the permanent first molar and we have prevented the impaction or ectopic eruption of the second bicuspid.

There is one extremely common condition in orthodontics which causes numerous problems and which, if my hunch about it is correct, would be amenable to preventive measures. The difficulty is that we have not considered it to be a preventive problem, and we may be hard put to devise preventive measures if we do so identify it. I am referring to tongue thrusting.

I am of the opinion that most tongue thrusting may be the result of early prolonged space in the anterior region following the premature loss of deciduous incisors and/or the slow eruption of the permanent incisors. The combined action of thrusting the tongue to close the system for swallowing and for making certain speech sounds for periods of two to twelve months or more, and perhaps for more than one period of time, should be sufficient not only to make the thrust habitual, but also to preserve the open bite environment which, in turn, perpetuates the need to continue the tongue thrust. The added effect of the tongue resting forward in such a space just because it is there, works in the same manner.

This may not be an exclusive mechanism. We recognize that thumb sucking may contribute to an open bite which then requires the tongue thrust to close the system and the vicious cycle proceeds. And, there may be other contributing factors. But, of them all, the one that appeals to me the most as the primary cause is the presence of space requiring the tongue thrust. It would take a great deal of thumb sucking to equal this.

We speak in terms of 80% of children having some tongue thrust. In a fair percentage of them the tongue thrust contributes to the creation of open anterior bite and protrusion. They would be worth preventing, if possible, not only for the decreased problem of malocclusion, but also for the decreased problem in speech. Speech problems frequently accompany anterior open bites, and frequently remain even after the open bite is reduced. The speech pattern has become habitual and does not automatically change when the dental environment changes. Think of the speech therapy that might be avoided if the cause of the problem could be prevented.

It sounds simple and might even be correct, but what do you do with an hypothesis? Well, if it's a good hypothesis, it should be tested. But, where would you test it? I am not aware that we have a facility conducting this type of clinical research. What is needed is a carefully controlled scientific experiment utilizing two comparable groups, one of which is a control and the other of which is equipped with preventive devices, as needed, to avoid the presence of space in the anterior region for more than some minimal period of time during the changeover from deciduous to permanent teeth. What kind of devices these may be is as problematic as the hypothesis itself. Conceivably it might take the form of a removable partial denture or a temporary fixed bridge of some kind or something entirely new. It would have as basic requirements that it did not interfere with the bite, nor with the eruption of permanent teeth, and that it be designed in such a way that it would not itself create tongue thrust problems.