the mouth is closed. The edges of the bands should also be close to the occlusal margins of the teeth, and the plane of metal close to this edge of the band. This is important, for it makes possible a very short spur, and consequently far less strain upon the band than when a long lever-like spur is used.

The other devices shown in the cut are for the retention of incisors and cuspids, and are so well known that I will not take up your time here with an explanation of them.

The next picture (Fig. 27) will show another case belonging to the same class we were last discussing, only this patient is much younger, and you can easily imagine how much more quickly and easily the teeth were adjusted to the positions shown in the study model, Fig. 28. The retaining device, as just described, is also shown here.

Fig. 29 shows a most pronounced case of this type, and you will note how greatly the bite is shortened in connection with the

bilateral distal occlusion. How unfortunate it is that the adjustment of the first molars could not have been accomplished early, to prevent this condition. No wonder the face both in front and in the profile, shown in Fig. 30, shows such a shortening and inharmony of contour, nor that it is so vastly improved after treatment, as shown in Fig. 31. The occlusion after treatment is shown in the study model, Fig. 32. I ask you what would have been the effect on the facial lines if extraction had been resorted to in this case?

Cases belonging to the subdivision of this division of this class are of course numerous. Fig. 33 shows one that is typical, or uni

laterally distal, and Fig. 34 represents the case after the shifting distally of the left molars, premolars, and cuspid of the upper arch, as well as the correction of the positions of the incisors, and the shifting mesially of the left molars, premolars, and cuspid of the lower arch was accomplished. You will notice how the length of overbite of the incisors has also been improved, as it must be in all such cases if this plan of treatment be followed.

The next picture (Fig. 35) shows a most pronounced case belonging to the first division of this class, or the buccal-breathing and protruding-incisor type, and notwithstanding that there is such great prominence of the incisors, yet the molars and premolars occupy the same positions as in all this great class, so there would be no more excuse for extracting two premolars from the upper arch in this case than there would be in the ordinary case of far less protrusion.

The next picture (Fig. 36) shows a study model of the occlusal surfaces of the upper teeth, and you will see by the spaces posterior to the cuspids how much the molars and premolars have been carried distally, and the next study model, Fig. 37, shows the corrected occlusion, although the teeth with their retainers have not yet settled into position sufficiently for the making of final, perfect models of the case.

I could show you a large number more, but they would all resemble this so closely in form and in detail of treatment that it would be but mere repetition. I will only add that in all these cases where I have sacrificed premolars I believe I have blundered, but this was before we had the Baker anchorage. Now there seems to be no longer excuse for such extraction.

Fig. 38 illustrates a case typifying a subdivision of Division 2, Class II., or unilateral distal occlusion. These subdivisions are perhaps more numerous than the parent type, and their treatment in so far as the malocclusion exists is identical with that described for cases bilaterally distal, the Baker anchorage being used only on the maloccluded side.

Fig. 39 represents the case after having been so treated and harmony of the occlusal planes established.

There is not time this evening to fully consider cases belonging to the third great class of malocclusion. I will show but one,that of a comparatively young person,-in Fig. 40.

I believe that if we begin treatment early, retain all of the