4: Extraction of teeth

4 Extraction of teeth

CLINICAL AND RADIOGRAPHIC ASSESSMENT

Not all extractions are straightforward; sometimes teeth fracture or there is risk of damage to adjacent structures during the process. It is important to attempt to evaluate, before the extraction, the likely degree of difficulty and the chances of adverse events. This maximizes the chance of things going according to plan.

Clinical examination and radiographic assessment

Look for signs of limited access, as occurs with severe temporomandibular joint disease, burn scars around the lips or a restricted view due to abnormal tooth position or crowding. Teeth so displaced from the arch that forceps cannot be applied in the conventional way may be more difficult to remove. Incompletely erupted teeth require a transalveolar approach.

Increasing age is associated with more dense, inelastic bone, a greater risk of ankylosis and brittle teeth due to secondary dentine deposition. These increase the difficulty of tooth extraction.

A bulky alveolus and severe attrition (particularly of posterior teeth) are associated with difficult extractions. Cervical abrasion cavities, extensive restoration and clinically evident fractures all predispose to fracture during extraction. Extensive caries, especially at the site of application of the forceps beaks, also makes fracture more likely.

Radiographs may show extensive caries, large restorations, root-filled teeth (all of which may make fracture more likely) and also demonstrate bulbosity, curvature and other abnormalities of the root not visible clinically. The loss of bone due to periodontal disease, or increased density, influences ease of extraction. Also, if the tooth is likely to be in close relation to the inferior alveolar nerve or maxillary antrum it is important to assess that relation in advance.

Should you take a radiograph for every tooth to be extracted? No. But radiographs are indicated in the following circumstances:

EXTRACTION FORCEPS: HOW THEY WORK AND HOW TO SELECT THEM

The application of fingers alone would not produce sufficient controlled force to remove teeth. Forceps enable the practitioner to grasp a tooth firmly and apply leverage to it in any direction.

The design of forceps has remained remarkably constant over many years: it is difficult to improve on the basic shapes. All forceps consist of two blades and handles joined at a hinge. The inner aspects of the blades are concave to fit the root accurately; they should not touch the crown of the tooth. The blades have sharp edges to cut periodontal ligament fibres and are wedge-shaped to dilate the socket. The blades are applied to the buccal and lingual aspects of the root. There are many designs, but for the purpose of this book we will restrict discussion to those most commonly used.

Forceps for upper teeth

Forceps for extracting upper anterior teeth are of a simple design (Fig. 4.1). The handles are straight and 12–14 cm long, joined at a hinge to the beaks, which are 2–3 cm long. The handles are contoured on their outer surface to allow a good grip. The beaks are both concave on their inner aspect (Fig. 4.2), shaped to fit around the root of the tooth as closely as possible (Fig. 4.3) when the forceps are applied in the long axis of the tooth. The beaks are applied labially and palatally. All extraction forceps can be seen as modifications of this basic design.

These forceps can be applied to the long axis of anterior teeth, gaining access by the patient opening their mouth fairly widely (Fig. 4.4). However, if one were to attempt to use these forceps on an upper first premolar, there is a risk of traumatizing the lower lip. Forceps for use in the upper jaw further back than the canine have a curve in the beak (Fig. 4.5), which keeps them above the lip when they are in the long axis of the tooth. The beaks of these forceps are also concave on their inner aspect to fit the root of upper premolars.

These forceps could be used to extract posterior teeth, but for teeth with multiple roots, forceps are available with beaks specifically designed to fit complex root forms (Fig. 4.6). In principle, the more closely the beaks are adapted to the roots, the more widely the forces of extraction are distributed and the lower the likelihood of tooth fracture. The buccal beak has a point to fit into the bifurcation, with concavities on either side to fit around the buccal roots and a broader concave palatal beak. Because of this distinction between buccal and palatal beaks, there must be separate designs for left and right sides of the mouth.

For all upper extractions it is necessary to push firmly in the long axis of the tooth during extraction (see p. 32). For this reason many forceps for upper posterior teeth have a curve at the end of the handle (‘Read pattern’) so that they fit in the palm of the hand (Fig. 4.7). This inevitably means that such forceps must have separate designs for right- and left-handed operators (Fig. 4.8).

Access for extraction of teeth far back in the mouth can be difficult. A further variation involves a step in the beaks of the forceps (Fig. 4.9), which enables you to put the beaks on the upper third molar whilst avoiding the lower lip.

HOW TO HOLD FORCEPS TO BEST EFFECT

During all extractions it is necessary to push the forceps firmly towards the apex of the tooth. For maxillary teeth this is achieved by pushing on the end of the handle. In order to maintain that position, the end of the handle must rest centrally in the palm of the hand, with the wrist held straight (Fig. 4.12). The first three fingers are placed around the handles and initially the little finger is placed between the handles to help hold them apart. The little finger can be brought around the handle once the forceps are thoroughly applied. The thumb is braced on the handle but not placed around it—that could produce too great a compressive force and tends to misalign the instrument in the hand. The thumb should not be placed between the handles as this also misaligns the instrument and tooth breakage during extraction risks injury to the thumb.

For mandibular extraction the position of the forceps is very similar (Fig. 4.13), but it is not necessary to push in the long axis of the forceps, so rigid adherence to keeping the end of the handle in the palm is less important. Nevertheless, the further the hand is from the hinge and beaks, the greater will be the leverage applied, and the lower the amount of interference of the hand with the patient’s face.

HOW TO POSITION YOURSELF AND YOUR PATIENT

The positioning outlined below is intended for extraction in a patient who is sitting up or partly supine and for an operator who is standing. It is perfectly possible to extract teeth low-seated, in the fully supine patient, but novices should start as shown here and modify the techniques for low-seated work later if they desire. The description assumes a right-handed operator, but a mirror image of the technique can be employed by left-handers.

Extraction of maxillary teeth

The positioning is determined by the need to push in the long axis of the tooth. The operator stands in front and to the right of the patient (Fig. 4.14). The operator’s legs should be spaced so that it is possible to push hard with the right leg which should be to the rear and straight. The left leg should be forward and slightly bent. Both feet should be close to the chair and pointed towards the patient’s head. The back should be kept straight. The patient should be tipped back by about 30° so that the surgeon can see directly into the mouth. The height of the chair should be adjusted so that the tooth to be extracted is about at the height of the operator’s elbow. The patient’s head is tipped just far enough to their right that access to the tooth is comfortable.

Extraction of mandibular teeth

For teeth in the lower left quadrant, the operator stands much as for maxillary extractions (Fig. 4.15), but the patient can be placed a few inches lower. When the operator’s back is straight and the forceps are applied to the tooth, both of the operator’s wrists should be in a comfortable neutral position. This will be helped if the patient turns slightly toward the operator.

For teeth in the lower right quadrant the operator stands behind the patient (Fig. 4.16) but beside the head, usually on the patient’s right (occasionally, depending on the angulation of the tooth, it is more comfortable to stand on the other side). The chair can be tipped further back than for the maxillary teeth (maybe as much as 45°) and its height can be a little lower than when standing in front for the left side. There is little advantage in spreading the legs widely; for this extraction one is pushing down.

The supporting hand

The left hand is used to support the jaw and stabilize it during extraction. It also holds soft tissue out of the way to permit good vision. For maxillary teeth, the index finger and thumb are placed either side of the alveolus adjacent to the tooth to be extracted (Fig. 4.17). This usually requires the elbow to be up in the air. The remaining fingers are either kept straight or bunched tightly, so that they do not rest hard against the face or eyes.

For extractions in the mandible two fingers and the thumb are used (Fig. 4.18). For the lower left this means placing the index and second fingers either side of the alveolus in the mouth and the thumb beneath the mandible outside the mouth to lift up. For the lower right use the index finger and thumb inside the mouth and the second finger beneath the jaw, supporting it.

It is important in all these manoeuvres to ensure that no soft tissues are trapped against the teeth, because this could cause pain or injury.

Jan 14, 2015 | Posted by in Oral and Maxillofacial Surgery | Comments Off on 4: Extraction of teeth
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