the lines of the molars, still in the lower jaw. Commencing with the first bicuspid and finishing with the wisdom tooth, the masticating surfaces of the teeth form two curves totally different from those of the six front teeth. First, the curve seen horizontally is concave from the cuspid to the wisdom tooth, and then it is slightly curved in the mouth, the molars leaning toward the tongue and the convex side of the curve being towards the tongue, while the concave side is towards the cheek, thus leaving more space between the wisdom teeth than there is between the bicuspids, according to the form of the tongue. For, it must not be forgotten that the tongue upon the inside of the mouth and the lips and teeth outside are continually active instruments in the regularization of the teeth during the period of formation.

Let us turn now to the upper jaw and take the six front teeth. We find nearly the same lines as below,—that is, from cuspid to cuspid, a curve with the convexity in front towards the lips. There is also another curve or convexity, of which the central incisors are

Fig. 2.

the longest, while the laterals are shorter, so that when the two rows of incisors close, the central incisors, upper and lower, touch before the laterals and act like scissors. (Fig. 2.) If we follow the line of the molars, we find that the arch of the incisors and cuspids is no longer preserved, but that the lines become nearly straight or rather slightly curved towards the interior of the mouth to meet the lower molars. Hence the wisdom teeth are much further apart than the bicuspids (Fig. 3). The curve seen horizontally, from the cuspids to the wisdom teeth, is convex towards the lower jaw, and the first molar is the largest, longest and most prominent of the dental arch. It is the same at each side, with some slight differences. We notice especially that the horse-shoe shape, which we so often see in the mouths of those unhappy victims who have fallen into the hands of "tooth-carpenters," is not a natural shape. These horse-shoe sets of teeth, which if placed upon a table teeth downward would touch at all their points, do not in any way correspond to the normal forms. When this normal form is perfect it is sometimes accompanied by a peculiar conformation of the lips, known among artists and sculptors

under the name of "Cupid's bow." The middle of the upper lip falls considerably, while at each side it rises in a graceful arch, which descending anew, rises finally at the commissure of the lips in a little curve, smiling even when the mouth is in repose. Now, take away the teeth from this mouth, and put into it a horse-shoe plate; the graceful lines and curves just described, which recall to us our celestial origin, disappear; the mouth becomes a mere slit or buttonhole; meaningless, except as an opening for the absorption of food. Every trace of beauty, as well as a great part of its usefulness, has disappeared.

If we change the arrangement of the teeth in the mouth in the converse way, that is, by diminishing the size of the arches, we make the expression of the lips heavy; and the power of producing clear and sonorous sounds is diminished. JSTo one can sing well unless the vault of the palate is perfect, and it is impossible for it to be so if teeth have been lost in the front of the mouth, or even if a large portion of several teeth has been lost. For example, we file off the tuberosities of the bicuspids and the first molars, so that the sides of these teeth are left flat, and we have only flat fillings to insert in the carious cavities. (Because, of course, we never touch a tooth with a file save from the greatest necessity.) The first effect of this filing is, that for several days, perhaps even for weeks, the patient loses sounds each time that he begins to speak. Little by little he acquires the habit of partially closing these openings between the teeth with the tongue and the cheeks. Besides, and what is still more unfortunate, the teeth lean towards one another, and in a short time we have surfaces approximating each other in the form of a dovetail, from which it is absolutely impossible to remove the remains of food accumulated there. Soon acetic fermentation, which is to be found especially in these hidden corners, performs its destructive work, and we have a renewal of caries nearly or quite as extensive as the surfaces which touch each other. As the tuberosity of each tooth has been removed, we have augmented the region susceptible of being attacked by caries, in proportion to the former good or bad form of the tooth. If the tooth was well formed, that is to say, short, rounded and yellowish in color, we have probably removed but little of its substance, for we have procured all the room necessary with but little filing. If, on the contrary, the tooth was delicate, long, and flat, we shall have been obliged to file considerably, perhaps largely, and the two approximal wTalls which have approximated are large in proportion. Caries recommences; the teeth are filled the second time after a further filing and the loss of a considerable portion of the remainder of the tooth.

Among these models are two to which I desire especially to call your attention. The first is that of a mouth in which the teeth have been necessarily filed, and well filed, and the fillings, inserted by Dr. Pugh, of Philadelphia, about eleven years ago, are still in a good state of preservation. In this case I see nothing better to do than to employ the file. As you see, it is one of the exceptional cases which proves the rule. The other model is that of a patient coming from New York, whose incisors are well filed (that is, if we can admit the utility of filing them at all), for the separation is much larger upon the lingual sides than upon the labial. Because of this shaping, these approximal surfaces have been so well cleansed since they were filled, whether it be by the action of the tongue, of foodr or of the brush, that caries has been entirely arrested. The molars in the same mouth, as you see, have been very badly filed with a flat file, which left an opening easy to fill up with the debris of food, and difficult to cleanse. Caries has consequently pursued its destructive work near the gums upon the first molar and second bicuspid, until there now7 remains of each scarcely the half.

In presenting to you the separator, I wished only to say that it would serve to slightly separate certain teeth and hold them steadily while they were being filled. If these teeth have been previously separated by cotton, tape, or other means, the separator holds them firmly during the operation without the least pain, after it has been once adjusted. When the filling is ended, another turn or two is given to the screw to obtain room enough to polish the fillings without removing those points which ought to touch each other when finished. There are certainly teeth which cannot be separated with this instrument, but as it may frequently be needed, and as it generally causes no pain, but sometimes even prevents the extreme tenderness which follows the gradual separation of teeth, it will without doubt soon be accepted by those who desire as far as possible to spare pain to their patients.

Several of my colleagues who are present this evening have seen operations done by the aid of this instrument, and they have had opportunity to question the patients as to their sufferings during the operations. It will, therefore, be easy to obtain the facts upon these points. Judging from my own experience, I should conclude that the filing of teeth, as it has been and still is practiced among the mass of practitioners, ie a bungling mode of obtaining room for delicate operations (Figs. 4 and 5).

Suppose, for example, two cavities opposite to each other, between the first molar and the second bicuspid. We can with a chisel or with a burr in the engine open a hole in the grinding surface of one of the

Pig. 6.

teeth, which shall expose perfectly the two cavities. This leaves the two sides adjoining the cavities in both teeth intact. If the cavities are near the gums, we can make our entrance from the buccal side, being careful to make the largest opening in the tooth which is most decayed. Sometimes it will be necessary, in order to obtain complete access, to cut both teeth, but generally one will be enough. Between the incisors and cuspids a little separation should generally be made writh cotton or tape during three or four days before the operation. Then, if the cavities are large, the teeth may be cut upon the linguo-approximal surfaces in such manner that the labial surfaces are not touched, and the fillings, being inserted from the lingual side, are not visible from the front (Fig. 6). If the cavities are small, we separate the teeth with tape or other means until there is enough space to work in without cutting at all. These examples are the general rule, for all the others are only modifications of these.

Now, having prepared the cavities, if we make use of a little wooden wedge between the two teeth, or the separator, which would be less painful to the gums than the pressure of the wood, we can fill with whatever material we choose without harming the original form of the teeth. If we use amalgam or other plastic filling, we

have only to put a small piece of thin platinum between the teeth to prevent the two fillings from uniting, taking it out the following day; then with a thin tape, waxed and dipped into some kind of powder, we can polish and shape these fillings in such a way as to increase their durability and the comfort of the patient very greatlyWhen this advantage is once well known, there will no longer be any difficulty in governing patients and making them submit to anything which is really necessary. If we are putting in gold, we save much time and uncertainty if we use cylinders or cushions of gold for the bottom of the cavity,—that is to say, gold folded upon itself so that the folds are parallel. These cushions or cylinders should be placed in the cavities so that the folds may be parallel with the bottom and walls. This gives us a foundation upon which we can add cohesive gold in ribbons or in crystal according to our personal manner of working.

During my discussions with Dr. Arthur—discussions friendly, though serious, and about which I was corresponding with him at the time of his death,—I examined separately in the museum of the University of Harvard and the Academy of Natural Sciences at Philadelphia, besides those which I could find in New York, more than 500 skulls, and I found only three upon which filing after the Arthur plan could have been practiced without harmful results to the teeth. I was upon the point of giving the results of these observations to the profession, when the death of my friend prevented me for the moment from combating his views, and since that period I have never found the time to take that work up again.

In conclusion, I recognize perfectly that the man whose leg has been crushed under a railway train must submit to the amputation of the limb, and we regard with great respect the surgeon who knows how to cut it off. But with how much more respect should we consider one who could save it. Admit in the same manner that there are circumstances in which the amputation of a certain part of the tooth is necessary. I plead only for the preservation and restoration as far as in us lies of all the organs committed to our care, the well-being of the patient being always the first consideration.

[The following note, just received from Dr. Bogue, is appended to the paper at his request.—Ed. Dental Cosmos.]

New Yokk, February 14, 1885. Dr. J. W. White:

Dear Sir: Dr. Perry showed me last evening, for the first time, his improved separators.

I find his incisor separator so marked an improvement upon my own form, that I desire to acknowledge its superiority.

Yours faithfully,

E. A. Bogus.