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.

 

Fig. 1.

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.

 

 

Fig. 2.   Fig. 3.

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),

 

 

Fig. 4.   Fig. 5.

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).

 

 

Fig. 6.   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.

 

Fig. 8.

Mode of holding forceps for the removal of upper teeth.

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.

 

Fig. 9.

Mode of holding lower “hawk’s bill” pattern forceps.

 

Fig. 10.

Mode of holding forceps of pattern shown in fig. 30.

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.

 

Fig. 13.

 

Fig. 14.

 

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.