HARMONIZING DIVERS COLORS. 507 upon the side of inserting those of a deeper tone than is really required, excepting when some of the natural teeth remain, and then faithfully matching or at least selecting a color that harmonizes, and will not be obtrusive or conspicuous. The canine teeth in nature are less translucent and more deeply shaded than the incisors or bicuspids. This should certainly be imitated so far as the canines are concerned; but, in the opinion of the writer, we shall produce a better effect with artificial teeth by not inserting bicuspids of lighter shade than the canines. The artificial tooth does not absorb the light as does the natural one, and when placed in shadow as the bicuspids in situ, they are rendered more conspicuous. Where natural teeth of divers colors are scattered, and the vacancies are to be supplied, it is our duty to harmonize in color each artificial tooth with its natural neighbor.* It will be manifest that it is simply impossible to carry all the foregoing suggestions into practice with some of the methods of constructing sets of teeth now in use. One of the greatest difficulties to overcome is the scientific one, viz., to discover and combine in just proportions the materials which will produce this wonderful imitation. In no other art with which the writer is acquainted have imitations of nature been carried even now to such perfection. The making of artificial flowers has perhaps come the nearest to it. Certain it is that, of the materials which chemistry has already furnished us, it is possible to obtain most wonderful results. The color of a tooth is dependent principally upon * I was required on one occasion to insert the four superior incisors. One of the canines was of exceedingly fair color; the other was very much discolored by a black amalgam filling on its anterior approximal surface, which the patient on no account would have disturbed. A block was made in which the side of the lateral incisor next the discolored canine was deeply stained with platina, and a most excellent imitation in color was produced, and the other teeth were vari-colored, grading in shade from one canine to the other. The effect was very good, destroying the conspicuousness which the discolored canine would have shown in contact with an unstained associate. 508 WANT OF INDIVIDUALITY IN ARTIFICIAL DENTURES. the proportion of its ingredients; its tone upon the action of the fire in burning or baking. The fault of many of the porcelain teeth of this country is the crudeness or rawness in their appearance-a lack of translucency, which a little more heat would very much improve. It would blend the colors more perfectly, give them more vitality, and soften down the hard and angular lines of the mold. It is perfectly in the power of our manufacturers, with the materials now in use, to make a general improvement. One thing which is much wanted is to increase the variety of darker shades; not by hurrying into the market a lot of poorly baked blue or yellow teeth, but by a careful imitation of those organs in persons who have been habitually neglectful, until their teeth have acquired a tone or color which can not be removed. While the dentist at large is dependent upon the manufacturer, he must cultivate his taste until he is able to select the most suitable shade which is prepared for him. When one or more of the front teeth are remaining, either above or below, in a fair state of preservation, a tolerably correct idea may be gathered of what is needed; and careful observation made of just such cases, as well as of all partial sets, taking into consideration the age, complexion, etc., will do much to improve his judgment and enable him to make suitable adaptations when he has no such help. When we consider the infinite variety of the human countenance, and the equally infinite diversity in form of the jaws which a dentist sees (no two being exactly alike), and then consider that there are thousands with a conformation of jaw peculiar to each, who are wearing artificial teeth of exactly the same size, shape, and color, in fact all cast in the same mold, and really belonging to but one individual, we begin to realize the paucity of our resources. In the loss of the teeth, the absorption of the processes, and the wasting away of the muscles and tissues, as we have seen, the greatest possible detriment is caused to the expres THE CULMINATION OF EXCELLENCE. 509 sion of the human countenance. The complete restoration of these features, with all their power of expression, by art -art so consummate in the selection, arrangement, and adaptation of its means as to defy detection-is one of the crowning glories of dentistry as an art. CHAPTER XXI. ANATOMY AND PHYSIOLOGY OF EXPRESSION. To no one does the study of the human face, in its various forms and aspects, recommend itself with more force than to the dental practitioner; for, called upon as he is, not only to relieve suffering humanity from the greatest pain to which flesh is heir, but also to repair the ravages of decay, either in efforts directed toward the preservation of the natural organs, or, when these are lost, to supply artificial substitutes, if he is not as quick to perceive and as able to retain in his memory the nice shades of expression of the same face, and the characteristic points of resemblance or difference between various individuals, as the sculptor or painter, he will fail in many essential particulars to meet all the just and proper demands upon him. Apart from this general interest shared by all in the human face, it is important that those engaged in certain departments of life should become thoroughly acquainted with the mechanism, so to speak, by which the record is made. To the speaker, whether in the pulpit, at the bar, or on the stage, gesture is all-important; to the artist, whether as a painter or sculptor, expression is everything; and last, though not least, to the dentist a faithful discharge of duty demands that he should, in the performance of his operations on the teeth, invariably endeavor to preserve the natural expression of the face, or when the ravages of decay have eventuated in the loss of the dental organs, that the lost expression should be restored by the introduction of properly A KNOWLEDGE OF PHYSIOGNOMY INDISPENSABLE. 511 constructed and adapted artificial substitutes. To each and all of these, and particularly to the latter, if they desire to attain the highest possible point of excellence, an intimate acquaintance with the ANATOMY AND PHYSIOLOGY OF EXPRESSION is indispensable. It is generally conceded that the proportionate relation of the bones of the face to those of the cranium has much to do with the moral and mental qualities of the individual; in other words, that a high order of intellect is usually manifested by those in whom the cranium is large, the forehead broad and high, and the bones of the face small; while the animal propensities are generally evinced in a marked degree, and preponderate over the intellectual, in those with depressed foreheads, compressed temples, and large and massive jaws. The opposite extreme is sometimes presented, in which the bones of the face are so disproportionately small, in comparison with the cranium, as to constitute a marked deformity. Again, a want of harmony between the different bones of the face is occasionally presented; as, for instance, when the inferior maxilla is very large and massive, or unusually small, in comparison with the superior maxilla, or vice versa. This hypertrophied or atrophied condition may occur in any of the bones, and of course when existing will mar the harmony of the surrounding parts. In extreme old age, the atrophied condition of the jaws, due to the gradual loss of all the teeth and the absorption of the alveolar processes, produces that decided alteration in the features of the aged with which we are all so familiar. The change which invariably takes place in the angle of the lower jaw in consequence of the disappearance of the teeth and processes causes the chin to project, and when the jaws are closed the nose and chin approximate each other. Even when apart, the falling in of the lips so encroaches upon the oral cavity as to make it too small for the tongue, and thus renders the speech feeble and indistinct. It is here that the |