CHAPTER I.

The General Principles of Extraction of the Teeth.

As an operation, extraction of teeth is fortunately becoming more rare, but even now large numbers are needlessly sacrificed, in many cases owing to ignorance on the part of the patient of the value of the teeth, at times to lack of knowledge on the part of both operator and patient of the modern methods of conservative dentistry. With the assistance of antiseptics in the treatment of root-canals, and the increase in knowledge of the methods of filling and crowning teeth, it is now possible to retain many which would in former days have been extracted--indeed it may be said with truth that all teeth and many roots are capable of being saved and rendered useful, with the exception of--

(1) Those teeth whose roots are much shortened by absorption.

(2) Those teeth from which the alveolar process has disappeared to such an extent as to leave them quite loose; and

(3) Those teeth attacked with chronic periodontitis, which, in spite of treatment, tends to become worse.

Special circumstances naturally alter cases; for instance, with patients the subjects of nervous prostration, or feeble in health, a lengthy operation is often contra-indicated, and under such conditions extraction may be preferable to the lengthy and tedious processes of conservative treatment. Another indication for extraction is in cases of teeth setting up or aggravating ulceration of the tongue, lips, or other soft parts of the mouth. Teeth fractured in a longitudinal direction should generally be removed, and the same rule applies to those which are so misplaced as to be incapable of being brought into the normal arch. In crowded conditions of the teeth extraction is often called for, and under such circumstances is really conservative treatment.

If extraction be determined upon, _a careful examination of the tooth_ to be removed should be made. This will allow some idea to be formed of the amount of sound tissue present, and also of the force which will be necessary for the dislodgment of the tooth. In the case of roots, the edges must be defined, and for this purpose a blunt probe, similar in pattern to that shown in fig. 1 will be found useful.

=Instruments.=--The instruments in general use for the removal of teeth are forceps and elevators. _The Forceps_ is an amplified pair of pincers or pliers. It is made up of three parts, namely, the blades or portions beyond the joint which are applied to the tooth, the joint itself, and the handles. Forceps should be made of fine steel, should be light and yet strong enough to withstand without bending any strain that may be put upon them.[1] The blades should be shaped to fit the tooth they are intended to remove, and they should be clear of the crown when applied. On longitudinal section a blade should present a thin wedge-shaped appearance. Two kinds of joints are met with. In the first variety one half of the forceps passes through a slot in the other, the two being held together by a rivet passing through the centre (fig. 2). In the second variety (fig. 3) the two halves are held together side by side by a screw or pin which takes the entire strain. Most forceps of English manufacture are made on the latter plan, which has the advantage of permitting the instrument to be easily cleaned; it also allows a slight lateral movement of the two halves--a point of some practical importance. It is urged against this style of joint that it is weak; in practice, however, this is not found to be the case.

The handles should be of a size and shape to lie comfortably in the palm of the hand, and should be in such relation to the blades that when the latter are applied in the direction of the long axis of the tooth, the handles clear the lips.

As a general rule, in forceps designed for the removal of the anterior teeth in the maxilla, the blades and handles are in the same line (fig. 4),

while for the upper back teeth the handles form a curve of greater or less extent with the blades (fig. 5). In forceps for the lower teeth the blades are bent down from the handles to an angle of nearly ninety degrees. In one class, namely, the hawk’s-bill, when the blades are applied to the tooth the handles are at right angles to the line of the arch (fig. 6), while in other classes the handles are in line with the arch (fig. 7).

The manner of holding forceps is shown in figs. 8, 9, 10. The handles should rest comfortably in the palmar surface of the hand, and in such a manner that the end of one handle rests between the thenar and hypothenar eminences--a portion of the hand where force can be applied with advantage.

The thumb placed between the handles acts as a regulator to control the amount of pressure of the blades upon the tooth. As a precaution it is well to have the ball of the thumb well between the handles, so that the pressure is counteracted not only by the soft tissues, but also by the terminal bony phalanx of the thumb. If this precaution be not observed, any sudden crushing of the tooth may be accompanied by a severe and very painful contusion of the operator’s thumb.

_The Elevator_ consists of two parts--the handle and the blade. The former, usually made of wood or ivory, is about four inches in length and of a shape suitable to allow a firm grip being obtained of it by the hand. The blade is made of fine steel, and is about two inches long. Elevators are of two varieties, straight and curved. In the first form the blade is thin, about one-fifth of an inch in breadth, one surface being made convex and the other flat. The point of the blade may be rounded as shown in fig. 11, or spear-shaped, as shown in fig. 12.

In the curved variety, the terminal half inch of the steel portion of the instrument is bent at an angle with the shaft of the instrument (fig. 49). The edge of the blade of an elevator should always be kept sharp.

The method of holding an elevator is shown in fig. 13. The handle should rest comfortably in the palm of the hand, the first finger lying along the blade and being brought near the point so as to prevent the instrument slipping. When using the elevator for the removal of teeth on the right side of the mandible, the finger should lie along the curved side of the blade, and on the flat side when extracting teeth on the left side.

_The Screw_ (fig. 14) is an instrument which on rare occasions is useful for the removal of deep seated roots.

After being used, instruments of every kind should be freed from all foreign matter and then carefully sterilised.

The next point which demands attention is the =position of the operator and patient=. The chair should be placed before a good light, and if a proper dental chair is not to hand an ordinary arm chair may be utilised; failing this, two ordinary chairs may be placed back to back, on one of which the left leg of the operator should be raised to form a rest for the patient’s head. The patient should be placed in such an unconstrained position as will allow the operator to exert all necessary movements with freedom.

The operator should place himself so as to use his force to the greatest advantage. His left arm may be utilised, if necessary, for steadying the movements of the patient’s head, while the fingers of the left hand can be employed--

(1) To keep the cheek and other soft parts away so as to obtain a clear view of the tooth to be extracted and its immediate neighbours;

(2) To support the mandible;

(3) To grasp the alveolus and so allow some idea to be gained of the effect of the force employed.

The special positions for the removal of different teeth will be described in chapter ii.

It may be advantageous, before describing the steps of the operation of extraction, to refer briefly to a few =points in the anatomy of the teeth and jaws= which have a direct bearing upon the manner of carrying it out.

If the teeth be examined it will be noticed that they are capable of division into--

(1) Teeth with single, rounded tapering roots;

(2) Teeth with single roots more or less irregularly flattened or curved;

(3) Teeth with multiple roots.

Under (1) are included the upper incisors (temporary and permanent) and the lower bicuspids; (2) the lower incisors and canines (temporary and permanent), and also the upper canines and bicuspids; (3) the upper and lower molars (temporary and permanent) and frequently the first upper bicuspids.[2]

The shape of the roots, as we shall subsequently find, has an important bearing upon the manner in which force is to be applied when severing them from their attachments.

A correct acquaintance with the disposition of the alveoli of the teeth is of importance for skilful and successful operating. Fig. 15 gives a general idea of the appearance of the alveoli, but it is needless to say that a full knowledge can only be really obtained by a careful study of the bones themselves; by this means, too, some idea of the strength of different portions of the alveolar borders can be obtained--a matter of some moment when applying force in the process of removing a tooth from its socket. The points to be specially noted in the maxilla are the thinness of the outer alveolar wall as compared with the inner, the prominence of the canine socket, and the cancellous character of the bone in the region of the third molar. In the mandible the outer alveolar border will be seen to be thinner than the inner, with the exception of that portion in the region of the

third, and often of the second molar; another fact worthy of attention is that at the posterior portion of the socket of the third molar the bone is moderately dense.

=When performed with forceps the operation of tooth extraction may be divided into three stages:--=

(1) Adaptation of the forceps to the tooth.

(2) Destruction of its membranous connections with, and dilatation of, the socket.

(3) Removal of the tooth from the socket.

In the initial stage the _first step_ is the application of the blades, and, in this connection, care must be taken to see that the points pass between the gum and the tooth, and also that they are applied parallel with the long axis of the root. It is, as a rule, best first to apply the blade on the side of the tooth most obscured from view, and then lightly to close the other upon the opposite side. The blades should then be forcibly pressed upwards or downwards, as the case may be, in the direction of the apex of the root; a slight rotary or wriggling motion will often be found of assistance in the process. This “pressing” movement should be continued until a firm hold of the root has been obtained--a point of great importance, as upon it the successful removal of the tooth in a large measure depends. The handles should next be firmly closed, so as to give the blades a good grip, and the amount of pressure applied should be such, that when movement has commenced the blades do not ride upon the surface of the root. The amount of pressure to be applied must naturally vary according to the character of the tooth to be removed, and the resistance offered by the alveolar process. The thumb placed between the handles of the forceps, as previously pointed out, should counteract the pressure applied to the root and prevent crushing, which, should it occur, may make the subsequent removal very difficult.

The _second stage_--the destruction of the membranous attachments and dilatation of the socket--is accomplished by employing force in either a rotary or a lateral direction. The movement to be employed depends upon the form of the root or roots to be removed and the resisting strength of the surrounding hard structures, and at this point it need only be remarked that rotary motion is alone admissible in the case of teeth possessing a single conical root.

The _final stage_ is carried out by exerting extractive force in the direction of the long axis of the tooth, and also in that of least resistance; the latter is determined by a knowledge of the anatomy of the alveolar border, and by the sensation conveyed to the hand through the forceps.

=The removal of a tooth with a straight elevator= is accomplished in the following manner. The blade, with the flattened surface towards the tooth to be removed, is inserted between the root and the alveolus, the instrument being kept as far as possible parallel with the anterior surface of the crown. The blade is then forced downwards so as to reach the root at as low a point as possible; the handle of the elevator is then rotated away from the direction in which the tooth is to be removed. This has the effect of both raising the tooth in its socket and displacing it in the required direction. One such movement of the instrument rarely suffices for the removal of a tooth, a second, and sometimes a third grip, each time nearer to the apex of the root, having to be obtained.

The method of using a curved elevator will be described in dealing with the removal of the roots of lower molar teeth.

=The wound resulting from the removal of a tooth= is a lacerated one, and heals by “granulation.” The socket immediately after the operation becomes filled with coagulated blood, which is eventually replaced by granulation tissue, followed at a later period by the formation of loose cancellous bone.

A varying amount of absorption of the alveolar border always follows the removal of a tooth, the continuity in the surface of the gum being restored by ordinary cicatricial fibrous tissue.

The wound is best treated by keeping the parts carefully cleansed as far as possible from all foreign matter, and for this purpose an antiseptic mouth-wash[3] should be used several times a day. From the wound resulting from the extraction of an upper tooth the discharge drains away in a natural manner owing to the orifice being the most dependent part. From the wound caused by the removal of a lower tooth such is not the case, and should suppuration take place the socket must be frequently syringed with some antiseptic solution, and if necessary, packed.

=The Extraction of the Temporary Teeth.=--Although the actual details of the extraction of the temporary teeth do not differ from those of the permanent teeth, there are, nevertheless, one or two points to which attention may with advantage be directed. First and foremost, a child should not be deceived, and if it is necessary to extract a tooth, the child should be told and not taken unawares. When, too, a child resists having a tooth removed, the operation must not be forcibly carried out, for by a little patience and moral suasion on the part of the operator, the better side of a child’s nature can generally be gained. It should also be remembered that anæsthetics are quite as needful for the extraction of the temporary as the permanent teeth, the pain to be borne by a child being quite as great as that to be endured by an adult.