The challenge of Class II, Division 1 malocclusion

Abstract

I T IS important for the orthodontist to have a proper concept of what a mouth ought to be, of what it ought to do, and of how it ought to look. In fact, we all have some idea of what a Class II, Division 1 case is, although we have been troubled with all sorts of artificial classifications of malocclusion. Angle’s classification is very artificial, and it is based upon the three different ways the upper and lower first molars may be intercusped. Simon made a more thorough study of malocclusion from the standpoint of variations, and to some extent his classification is based upon anthropology. The profession, however, did not much appreciate his classification. We may say that all classifications are artificial, that they are just made to fit the mind of man. This is true in botany, in zoology, in bacteriology, and in all the other sciences. We know well how biologists crave a natural classification, but they have never found one. The elements may be conveniently, but not accurately, classified according to their true nature. We can learn, however, to identify them. In spite of its artificiality, Angle’s classification is widely used. It does convey a picture of conditions of a Class II case in such a way as to make a very superficial diagnosis possible. The different forms are similar, so that their treatment can be discussed as if they did make a true group. The same can be said of Class III cases. It is Class I, the great unclassified group, that is truly chaotic. The mesiodistal disturbances in the interlocking of the cusps is a definite symptom in Class II malocclusion. The recognition of this disturbance and the desire to treat it have led orthodontists to correct it mesiodistally instead of just laterally by expansion, as they did in the past. Of course, we know that this anteroposterior disturbance in a Class II case is just one of the symptoms that accompany and define this peculiar form of malocclusion. Symptoms are so numerous and the variations are so wide that it would seem unwise to mention some of them and ignore others that are equally important. It is enough to emphasize that in a mesiodistal tooth malrelation, mainly in a Class II case, there are infinite variations of different symptoms which have only the distal tooth relationship in common. Orthodontists have also noticed that only when this anteroposterior symptom is properly corrected are they successful in achieving the other aims of treatment: adjustment of the perverted muscular function, correction of excessive overbite and overjet, the axial inclination of teeth, the rotations, the curve of Spee, and so on.