THE DENTAL ART,

A PRACTICAL TREATISE ON DENTAL SURGERY,

by CHAPIN A. HARRIS, M. D.

SURGEON DENTIST.

If then the teeth, designed for various use,

Decay and ache, ‘tis only from abuse,

And lo, triumphant art can well ensure,

At least a remedy, if not a cure.

Brown's Dentologia.

BALTIMORE:

ARMSTRONG & BERRY,

I. W. WOODS, PRINTER.

1839.

CHAPTER V.

IRREGULARITIES OF THE TEETH — THEIR TREATMENT.

The increased number of teeth, their larger size, and other circumstances, attending second dentition, often give the teeth of the second set an improper direction, and occasion much irregularity in their arrangement. But this rarely affects the deciduous teeth; because, unlike the others, they seldom meet with any obstacles to their ascent and final protrusion through the gum.

A disproportion between the size of the permanentes, and the anterior part of the jaw, sometimes prevents the teeth from taking their proper, places in the dental circles; but this seldom occurs, and even when it does, it is generally so inconsiderable, that it occasions but little disturbance. Irregularity is most frequently produced by a premature loss of one or more of the temporaries, and a consequent contraction of the maxillae, by an incongruity between the absorption of the fangs of the first denture and the growth of the second teeth, and by the presence of supernumerary teeth.

The first of these causes, is probably the most frequent. The second often occasions such disturbances in the arrangement of the teeth, as are very difficult to remedy. The last is of rare occurrence, but when it does happen, it produces the worst kind of irregularity.

Irregularity is generally confined to the incisors and cuspidati, though it sometimes extends to the bicuspides, and even to the dentes sapientias, but rarely to the first and second molares. These two latter classes of teeth like the temporaries, meet with no obstructions to their ascent and protrusion through the gums. But the incisors, cuspidati, and bicuspides, often make their appearance before the roots of the temporary teeth, immediately over them, have been absorbed; and even when the crowns of the deciduous teeth fall out before they appear, they are so much larger than the temporaries, that the space thus made is frequently not large enough for their reception.

The first molares, are the first of the second denture, that are cut; and hence, the teeth that are to fill the anterior part of the arch, are limited to the space occupied by the first set, and if this is too small, a slight irregularity, at least, must of necessity ensue.

The dentes sapientiae are sometimes prevented from coming out in their proper places, in the lower jaw, by a want of room between the second molares and coronoid processes; and in the upper, by a want of space between the second molares and the angle of the jaw.

When a bicuspis cannot occupy its proper place, it turns inward towards the tongue or outward towards the cheeks, according as it is in the lower or upper jaw. But this order is sometimes reversed. It is comparatively seldom that the harmony of the arrangement of these teeth is disturbed, and when it is, the derangement is generally much less than that to which the incisors and cuspidati are liable.

These latter teeth are frequently so much disturbed in their dentition that they are entirely excluded from the arches. In such a case they seldom appear behind it, but are usually thrown outwards towards the lips, to which they often are a source of great annoyance, by causing them to protrude, and sometimes excoriating the delicate membranes with which they are lined to such an extent that their extraction becomes indispensable. Besides this, they always occasion more or less deformity, and when they protrude a great deal, they are apt, on the reception of a blow, to cut the upper lip.

The incisors of the upper jaw, present a greater variety in the manner of their arrangement than any of the other classes of teeth. The centrals sometimes appear before the dental circle, but much more frequently behind it: at other times, their lateral edges are turned either directly or obliquely towards the lips. The irregularity of these teeth, however, is much more generally characterized by an overlapping of their sides.

The laterals sometimes appear half an inch behind the arch, in the roof of the mouth, and sometimes before it. At other times, their sides are situated like those of the centrals, just described.

When any of the upper incisors are very much inclined towards the interior of the mouth, the lower ones, at each occlusion of the jaws, shut before them, and thus become an obstacle to their adjustment. This is one of the most difficult kinds of irregularity to remove, and one that often interferes with the lateral motion of the jaws.

The under front teeth sometimes shut in this manner even when there is no deviation of the upper to the interior. Here the irregularity is owing to a preternatural elongation of the lower jaw, which more frequently results from some fault in the dentition of the second denture, than from any defect congenital with the jaw itself.

Sometimes, the superior maxillary arch is so much contracted, and the front teeth in consequence so much projected, that the upper lip is prevented from covering them. Cases of this kind, however, are of rare occurrence, but when they do occur they occasion much deformity of the face, and are a species of irregularity very difficult to remedy.

From the same cause, the lateral incisors are sometimes shut out from the row, and appear behind the centrals and cuspidati, the dental circle being filled up with the other teeth.

There are many other deviations in the arrangement of these teeth. Mr. Fox mentions one that was caused by the presence of two supernumerary teeth of a conical form, that came up partly behind and partly between the central incisors, which, in consequence, were thrown forward, while the laterals were placed in a line with the supernumeraries; the central incisors, though half an inch apart, thus formed one row and the lateral sand supernumeraries, another. Mr. F. says, he has seen three cases of this kind.

This description of irregularity, is rarely met with, I have, however, in the course of my observations seen several cases.

Cases are occasionally met with, says M. Delabarre, of a transposition of the germs of the teeth, so that a lateral incisor takes the place of a central, and a central the place of the lateral. A similar transposition of a cuspidatus and a lateral incisor sometimes also occurs.

The incisors of the under jaw, being smaller than those of the upper, and in other respects less conspicuous, do not so plainly show an irregularity in their arrangement, nor are they so much affected by it. Still it should be guarded against, for any such disturbance, whether in the upper or lower jaw, is productive of injury to the health of the teeth, and to the beauty of the mouth.

The growth of the inferior permanent incisors is sometimes more rapid than the absorption of the roots of the temporary. In such a case, the former emerge from the gums behind the latter, and sometimes so far back, that they very much annoy the tongue, and interfere with the enunciation. At other times, the permanent centrals cannot come into their proper places, because the space left for them by the molting of the temporaries, is insufficient for their reception. The irregularity in the former of these two cases, is greater than in the latter. The same causes, in like manner, affect the laterals.

M. Delabarre mentions a defect in the natural conformation of the jaws, by which the upper frontal temporaries on one side of the medial line are thrown on the outside of the lower teeth, while the similar teeth, on the other side of the same line, fall within. The same disposition, he says, may be expected, unless the defect be previously remedied, after the dentition of the permanent teeth.* I have never met with more than two cases of this sort, and I did not see the subjects of even these, until after they had become adults.

*Enfin il y a une espèce de torsion de l'une ou de l'autre mâchoire, et quelquefois de toute les deux, qui fait que les dents temporaires supérieures antérieures recouvrent les inferieures, d'apaes la meilleure disposition; tandis qu' a commencer de la ligne médiane, les semblables dents de l'autre cote, rentrent en dedans des inferieures; il est probable, dan ce cas, que si 1'on n'y obvie, la même disposition se reproduira pour la seconde dentition. — Traite De La Seconde Dentition, p. 136.

THEIR TREATMENT.

The efforts that are made to remedy or remove the irregularities of the teeth, should always be in strict accordance with the indications of nature. Whenever the permanent teeth are prevented from taking their proper places, she endeavors to correct the evil, and if foiled in her efforts, exerts herself for their destruction. But at what period these efforts cease, is somewhat difficult to determine. When the irregularity is neither great nor complicated, and its causes are removed before the nineteenth or twentieth year, the teeth of themselves soon find their proper positions.

When, however, the exertions of the economy are unavailing, recourse should be had to the aid of the dentist, which, if properly rendered, can in almost every case, produce symmetry and regularity from deformity and confusion.

The practicability of altering the position of a tooth, after the completion of its growth, was well known to many of the earlier practitioners; but, as before the commencement of the present century, the more particular object of the dentist was, the insertion of artificial teeth, this branch of dentistry met with but little attention. Fauchard and Bourdet, were among the first who turned their attention to it. They invented a variety of fixtures for adjusting such of the teeth as were not rightly arranged; but most of these were so awkward in their contrivance, and occasioned so much inconvenience to the patient, that their use was soon abandoned.

Mr. Fox, whose name must ever hold a distinguished place in the catalogue of those who have contributed most largely to this department of surgical science, was the first to give explicit directions for remedying the irregularities of the teeth. These have formed the basis of the established practice for the last twenty-five or thirty years, and this long trial has proved that they were founded upon a knowledge of the laws of the economy, and much practical experience.

In describing the treatment for irregularity, I shall notice the means, by which some of its principal varieties may be removed; otherwise, the application of the principles of treatment would not be well understood, since it must be varied to suit each individual case.

Whenever any irregularity is discovered in the second denture, the sooner it is rectified the better, for, in general, the longer a tooth is allowed to occupy a wrong situation, the more the difficulties of its adjustment will be increased. The position of a tooth may sometimes be altered, after the fourteenth or fifteenth year, but generally, it is better not to delay the application of the means until so late a period. For a change of this kind may be much more easily affected, before the several parts of the osseous system have acquired their full size, and while the process of new formation is in vigorous operation, than it can be after the osseous growth has been completed.

If, previously to this time, there be any pressure against a tooth, it causes an absorption of the side of the alveolus against which its fang is pressed. But this does not necessarily destroy the socket, for as the internal paries is carried off by the absorbents, the external of the same side is thickened by a deposition of new bone; and the vacuum thus made on the opposite side, is also filled up.

Though this pressure, at a later period of life, would occasion an absorption of the alveolus, there would be no corresponding osseous deposition; and thus, not only would the tooth be loosened, but a morbid diathesis would be induced in the periosteum of its fang, in the alveolar membrane, and in the gum, which would, in all probability, very much injure the other teeth.

The age of the subject, therefore, should always govern us in forming a prognosis of the practicability of removing an irregularity. Previously to the fifteenth year, we may almost always form a favorable one, but after this time, our efforts will be less likely to succeed.

The first thing that should claim our attention in the treatment of these deviations, is the removal of their causes. Whenever, therefore, the presence of any of the temporaries has given a false direction to one or more of the permanent teeth, they should be removed, and the thumb or finger should, from time to time, be properly pressed upon the teeth thus wrongly situated. This, if the irregularity has been occasioned by the remaining of a diciduous tooth, will, generally, be all that is requisite.

But, when it is the result of a narrowness of the jaws, either natural or acquired, one of the secondary teeth on each side of the jaw should be removed, in order to make room for the admission of those that are improperly situated. The second bicuspids are the teeth that are generally extracted, and their places are soon filled up by the falling back of the first, which usually makes ample room for the adjustment of the cuspidati and incisors. But if the first bicuspids, of themselves, do not fall back into the stations made for them, a ligature of silk should be tied round them and the first molares, which should be renewed every two or three days, until the desired result is produced.

The most frequent kind of irregularity resulting from a narrowness of the jaws, is the projection of the cuspidati. These teeth, with the exception of the second and third molares, are the last of those of the second denture that are cut, and are consequently more liable to be thrown out of the arch than any of the others, especially when it is so much contracted as to be almost entirely filled before they make their appearance. The common practice, in cases of this kind, is to remove the cuspidati. But, as these teeth, contribute more than any others except the incisors, to the beauty of the mouth, and can, in almost every case, be brought to their proper places, the practice should certainly be discarded.

Therefore, instead of removing these teeth, room should be made for them by drawing two of the bicuspides. Much judgment, however, is requisite to determine which class of these teeth to remove. If, between the first bicuspides and the lateral incisors, there be spaces of one-half the width of the cuspidati, the second bicuspides should be extracted instead of the first; but if there be no such spaces, the first should be drawn; for although these might be carried far enough back, after the removal of the second, to admit the crowns of the cuspidati between them and the lateral incisors, yet still there would not be a perfect harmony of arrangement, for the fangs of these teeth would still cross each other; so that those of the bicuspides, would be found deeply seated in the arch, while those of the cuspidati would be thrown forward so much, that they would occasion considerable prominences in the gums that cover their alveoli; which, in consequence, would be gradually absorbed, and thus the teeth would be loosened and caused to drop out.

But when there are spaces such as have been just described between the lateral incisors and first bicuspides, a disturbance of this kind will never occur, and when this is the case, the first bicuspides should never be removed, unless there be an irregularity in the arrangement of the incisors that cannot be adjusted in any other way, and at the same time leave room for the cuspidati.

The first bicuspides are next to the cuspidati in importance; hence, they should never be removed, unless it be absolutely necessary for the adjustment of the teeth occupying the anterior part of the arch.

The bicuspides are seldom disturbed in their arrangement, but when one of them is not in its proper position, and there is a considerable crowding of the teeth that are anterior to it, it should be extracted; for, although the irregularity itself may not be very conspicuous, yet a degree of pressure will be kept up between the other teeth, which must of necessity be injurious.

The treatment of irregularity of the incisors of the upper jaw, is generally more difficult and complicated than that of the lower incisors. These teeth are more conspicuous, and, when well arranged, contribute more than any others to the beauty and pleasing expression of the mouth; their preservation and regularity are, consequently, of the greatest importance. Hence, the practice of removing the laterals, when they are situated behind the centrals and the cuspidati, and when the dental arch is not completely filled without them, is one that cannot be too strongly deprecated. Without these teeth, the beauty of the mouth, however well all the others may be arranged, is incomplete. They should never be removed, unless their arrangement, and that of the other teeth, are such, that their adjustment is impossible.

One of the most difficult kinds of irregularity to rectify, is, when the central incisors are so situated that their cutting edges, instead of being in a line with the arch, form an angle with it of from forty-five to ninety degrees. This peculiarity is rarely met with in both centrals, but often in one, while the other occupies its proper position.

Some practitioners have recommended, when the space between the lateral incisors is equal to the width of the crooked centrals, to correct this species of irregularity, either by twisting the centrals suddenly round with a pair of forceps, or by extracting and immediately replacing them in a proper position.

I cannot, however, join in these recommendations, because, if a tooth be extracted, or forcibly and suddenly turned in its socket, the dental vessels, from which its living principle is derived, are severed, and though its alveolar connection may be partially re-established, and an imperfect degree of vitality thus kept up, yet it will ever after be deprived of the animation and brilliancy which are peculiar to healthy teeth; a morbid diathesis in the relative and contiguous parts will be induced, which will end not only in the destruction of the tooth, but also in the great injury of the adjacent teeth.

These teeth, moreover, in consequence of the transverse being greater than the horizontal diameter of their fangs, can neither be suddenly twisted in their sockets, nor taken out and replaced with their labial surfaces outward, without great injury to the alveoli.

This description of irregularity, however, may be rectified in the following manner, without being attended with any of the evils above described. For this purpose, a gold band should be made and accurately fitted to the tooth. Ligatures are then to be attached to the sides of it, that will front the exterior and interior part of the mouth, after it shall have been placed upon the tooth. The ligature on the interior part of the band, should be brought forward between the irregular tooth and the lateral incisor, and then carried, on the outside of the circle, back to the first or second bicuspis, to which it should be made fast. The ligature attached to the anterior part of the band should be taken back between the centrals, and then extended, on the inside of the arch, to the cuspidati or the first bicuspis, on the opposite side of the jaw, to which it also should be secured. These ligatures should be renewed every two or three days, and each succeeding one drawn a little tighter than the preceding, until the tooth be properly adjusted.

If both the central incisors are affected with this species of irregularity, we should wait a few weeks after adjusting one of them, until it becomes firmly fixed in its socket, before we attempt to move the other, lest the pressure of the ligature against the newly adjusted tooth should throw it back into its former position.

The band should be so adapted to the tooth, that it may not be moved by the force that will necessarily be exerted upon it by the ligatures. It should be stamped between a metallic cast and die of the tooth; the manner of obtaining which, will be described here after.

Before, however, any attempt is made to adjust the tooth, it should first be ascertained, whether there is space enough between the other teeth to admit of its being turned. If there is not, room should be made, by extracting the second bicuspides, and proceeding, as has been before described.

Treatment similar to this, is also applicable to the lateral incisors, when similarly situated.

Irregularities arising from the presence of supernumerary teeth, may generally be removed by their extraction; and if this is not effectual, then properly directed pressure should also be applied.

In all cases, in which the upper teeth of the front part of the mouth, are thrown forward and caused to project, by the narrowness of the jaws, the second bicuspides should be removed, unless the first molares be decayed, for then it is more advisable to draw them. The anterior teeth are, thus, allowed to fall back, and form a more regular curve. Mr. Fox, in cases of this kind, recommends, that the first bicuspides should be extracted, but, for reasons before stated, I think it better to remove the second.

There are other varieties of irregularities in the front teeth, but I shall only notice one, which, from its peculiar character, is sometimes exceedingly difficult to remedy. It is when one or more of the upper anterior teeth are placed so far back in the maxilla, that the under ones come before them at each occlusion of the jaws; and thus present an insuperable obstacle to their ever being remedied without the aid of art.

Of this variety, Mr. Fox enumerates four kinds: — The first is, when one of the central incisors is situated so far back, that the lower teeth shut over it, while the other central remains in its own proper place.

The second is, when both of the centrals have come out behind the circle of the other teeth, and the laterals occupy their own proper positions.

The third is, when the lateral incisors are thrown so far back, that the under teeth shut before them, while the centrals are well arranged.

The fourth kind is, when all the incisors are placed so far in, that the lower ones shut before them.

He might also have added to this variety of irregularity, a fifth kind, for it sometimes happens that the cuspidati of the upper jaw are thrown so far back, that they drop on the inside of those of the lower. I do not, however, recollect of ever having met with more than two cases of this arrangement.

This variety of irregularity is not always occasioned by the upper teeth's being thrown too far back; it is frequently consequent upon the too great length of the under jaw.

Two things are necessary in the treatment of the irregularities which have just been described; the first, is to prevent the upper and lower teeth from coming entirely together, by placing between them some hard substance, so that the former may not be hindered by the lower teeth, from being brought forward. The second is, the application of some fixture, that will exert a constant and steady pressure upon the deviated teeth, until they pass those of the lower jaw, that obstruct them.

For these purposes various plans have been proposed. M. Duval recommends the application of a grooved or guttered plate, but I cannot determine how it was applied, or in what manner it effected the object proposed, since he has given neither drawing nor description of it. It was, perhaps, as M. Delabarre conjectures, a sort of inclined die, which was so placed over the teeth that are more exteriorly situated, that it strikes, at each occlusion of the mouth, the inside of the teeth that meet it. An instrument based upon the same principles, is also mentioned by M. Catlin. But fixtures of this kind, as has been remarked by M. Delabarre, can only be used, when there is a deviation both in the upper and lower teeth.

M. Delabarre proposes to pass silk ligatures around the teeth, and in such a way, that a properly directed and steady force may be exerted on those that are too far back in the maxilla; while the jaws are prevented from coming in close contact, by means of metallic grates, fitted to two of the inferior molares.

This plan possesses the merit of simplicity, and occasions but little or no inconvenience to the patient; but it, sometimes, will not only be found inefficient, but also to loosen the teeth adjacent to those that are to be brought forward. The force on the irregular teeth, and those to which the ligatures are attached being equal, in opposite directions, the latter will be drawn back, while the former are being brought forward; and thus the means that are used for the correction of one evil, will sometimes be productive of another.

Of the various fixtures that have been invented, for the correction of these kinds of irregularity, that recommended by Mr. Fox is unquestionably the best. It consists of a gold bar about the sixteenth part of an inch in width, and of proportionate thickness, which is bent to suit the curvature of the mouth, and fastened with ligatures to the temporary molares of each side. It is pierced, opposite to each irregular tooth, with two holes. The teeth of the upper and lower jaw, are prevented from coming entirely together, by means of thin blocks of ivory, attached to each end of the bar by small pieces of gold, and resting upon the grinding surfaces of the temporary molares.

After the instrument has been thus fastened to the teeth, silk ligatures are passed around the teeth, that have deviated to the interior, and through the holes opposite them, and then tied in a firm knot, on the outside of the bar. The ligatures must be renewed every three or four days, until the teeth shall have come forward far enough to fall plumb on those that formerly shut before them, and acquired a sufficient degree of firmness to prevent them from returning to their former position. But as soon as the teeth shut perpendicularly upon each other, the blocks may be removed, and the bar alone retained.

For the last twelve or fifteen years, many practitioners, both in England and the United States, have substituted golden caps for the blocks of ivory, recommended by Mr. Fox; and, instead of simply bending the bar, they now stamp it between a metallic cast and die, so that all its parts, except those immediately opposite the irregular teeth, may be perfectly adapted to the dental circle. The apparatus, with these modifications, is both more comfortable, and less liable to move upon the teeth.

Mr. Fox directs, that the blocks of ivory should be placed upon the temporary molares, but the golden caps, that are now substituted, are entirely disconnected with the bar, and are often used after the molting of these teeth, they are therefore placed upon the first permanent molares.

The caps, since the teeth are prevented from coming together, will have to perform the function of mastication. They should therefore be placed upon the stoutest teeth; and it is for this reason that the molares should be selected to wear them.

The curved bar should be removed and washed every time the ligatures are renewed. If this be neglected, the particles of food that collect between it and the teeth, will soon become putrid and offensive, and may produce considerable inflammation in the gums.

Before we apply the apparatus, we should first ascertain whether there be sufficient space for the reception of the deviated teeth, and if there be not, room should be made in the manner before described.

Some diversity of opinion exists as to the most suitable age for removing these kinds of irregularity. Mr. Fox, it would seem, preferred the period immediately previous to the molting of the temporary molares, — probably the ninth or tenth year after birth.

Some think, that the fore part of the dental arch continues to expand until the second denture is completed, and that the bicuspides afford a better support for the ends of the bar than any other teeth, and are therefore content to wait until the fifteenth or even sixteenth year. But though the arch does sometimes thus expand, yet even when the expansion occurs, it is generally so inconsiderable, that very little advantage can be derived from it. Moreover, the arch, instead of expanding, is much more liable to contract, whenever a vacancy occurs in the dental circle, either by the extraction, or from the improper growth of one or more of the teeth; hence the difficulty is very apt to be increased by delay.

The evil, it is true, may be remedied at the fifteenth, seventeenth, or even eighteenth year; but yet it is never advisable voluntarily to defer it to so late a period.

The most that is required in the treatment of irregularity of the lower incisors, is to remove a tooth, and to apply frequent pressure to the teeth that are improperly situated. These teeth are less conspicuous than those of the upper jaw, and the loss of one of them, if the others are well arranged, is scarcely perceptible.