SPECIFIC TECHNIQUES FOR MAXILLARY TOOTH EXTRACTION
In the correct position for extraction of maxillary left or anterior teeth, the left index finger of the surgeon should reflect the lip and cheek tissue; the thumb should rest on the palatal alveolar process. In this way the left hand is able to reflect the soft tissue of the cheek, stabi-lize the patient's head, support the alveolar process, and provide tactile information to the surgeon regarding the progress of the extraction. When such a position is used during the extraction of a maxillary molar, the surgeon can frequently feel with the left hand the palatal root of the molar becoming free in the alveolar process before realizing it with the forceps or extracting hand. For the right side, the index finger is positioned on the palate and the thumb on the buccal aspect.
Maxillary incisor teeth.
The maxillary incisor teeth are extracted with the upper universal forceps (no. 150), although other forceps can be used. The maxillary incisors generally have conic roots, with the lateral ones being slightly longer and more slender. The lateral incisor is more likely also to have a distal curvature on the apical one third of the root, so this must be checked radio-graphically before the tooth is extracted. The alveolar bone is thin on the labial side and heavier on the palatal side, which indicates that the major expansion of the alveolar process will be in the buccal direction. The initial movement is slow, steady, and firm in the labial direc-tion, which expands the crestal buccal bone. A less vigor-ous palatal force is then used, followed by a slow, firm, rotational force. Rotational movement should be mini-mized for the lateral incisor, especially if a curvature exists on the tooth. The tooth is delivered in the labial-incisal direction with a small amount of tractional force.
The maxillary canine is usually the longest tooth in the mouth. The root is oblong in cross section and usually produces a bulge called the canine eminence on the anterior surface of the maxilla, The result is that the bone over the labial aspect of the maxillary canine is usually quite thin. In spite of the thin labial bone, this tooth can be difficult to extract simply because of its long root. Additionally, it is not uncommon for a segment of labial alveolar bone to frac-ture from the labial plate and be removed with the tooth.
The upper universal (no. 150) forceps is the preferred instrument for removing the maxillary canine. As with all extractions, the initial placement of the beaks of the for-ceps on the canine tooth should be as far apically as pos-sible. The initial movement is to the buccal aspect, with return pressure to the palatal. As the bone is expanded and the tooth mobilized, the forceps should be reposi-tioned apically. A small amount of rotational force may be useful in expanding the tooth socket, especially if the adjacent teeth are missing or have just been extracted. After the tooth has been well luxated, it is delivered from the socket in a labial-incisal direction with labial frac-tional forces.
If, during the luxation process with the forceps, the surgeon feels a portion of the labial bone fracture, a decision must be made concerning the next step. If the pal-pating finger indicates that a relatively small amount of bone has fractured free and is attached to the canine tooth, the extraction should continue in the usual man-ner, with caution taken not to tear the soft tissue. Howev-er, if the palpating finger indicates that a relatively large portion of labial alveolar plate has fractured, the surgeon should stop the surgical procedure. Usually the fractured portion of bone is attached to periosteum and therefore is viable. The surgeon should use a thin periosteal elevator to raise a small amount of mucosa from around the tooth, down to the level of the fractured bone.
The canine tooth should then be stabilized with the extraction forceps, and the surgeon should attempt to free the fractured bone from the tooth, with the periosteal elevator as a lever to separate the bone from the tooth root. If this can be accomplished, the tooth can be removed and the bone left in place attached to the periosteum. Normal healing should occur. If the bone becomes detached from the periosteum during these attempts, it should be removed, because it is probably nonvital and may actually prolong wound healing. This procedure can be used whenever alveolar bone is frac-tured during extraction.
Prevention of fractured labial plate is important. If during the luxation process with the forceps a normal amount of pressure has not resulted in any movement of the tooth, the surgeon should seriously consider doing an open extraction. By reflecting a soft tissue flap and removing a small amount of bone, the surgeon may be able to remove the stubborn canine tooth without frac-turing a larger amount of labial bone. By using the open technique, there will be an overall reduction in bone loss and in postoperative healing time.
Maxillary first premolar.
The maxillary first premo-lar is a single-rooted tooth in its first two thirds, with a bifurcation into a buccolingual root usually occurring in the apical one third to one half. These roots may be extremely thin and are subject to fracture, especially in older patients in whom bone density is great and bone elasticity is small. Perhaps the most common root fracture when extracting teeth in adults occurs with this tooth. As with other maxillary teeth, the buccal bone is relatively thin compared with the palatal bone.
The upper universal (no. 150) forceps is the instru-ment of choice. Alternatively, the no. 150A forceps can be used for removal of the maxillary first premolar.
Because of the high likelihood of root fracture, the tooth should be luxated as much as possible with the straight elevator. If root fracture does occur, a mobile root tip can be removed more easily than one that has not been well luxated.
Because of the bifurcation of the tooth into two rela-tively thin root tips, extraction forces should be carefully controlled during removal of the maxillary first premolar. Initial movements should be buccal. Palatal movements are made with relatively small amounts of force to pre-vent fracture of the palatal root tip, which is harder to retrieve. When the tooth is luxated buccally, the most likely tooth root to break is the labial. When the tooth is luxated in the palatal direction, the most likely root to break is the palatal root. Of the two root tips, the labial is easier to retrieve because of the thin, overlying bone. Therefore buccal pressures should be greater than palatal pressures. Any rotational force should be avoided. Final delivery of the tooth from the tooth socket is with trac-tional force in the occlusal direction and slightly buccal.
Maxillary second premolar.
The maxillary second premolar is a single-rooted tooth for the root's entire length. The root is thick and has a blunt end. Conse-quently, the root of the second premolar fractures only rarely. The overlying alveolar bone is similar to that of other maxillary teeth in that it is relatively thin toward the bucca, with a heavy palatal alveolar palate.
The recommended forceps is the maxillary universal forceps, or no. 150; some surgeons prefer the no. 150A. The forceps is forced as far apically as possible so as to gain maximal mechanical advantage in removing this tooth. Because the tooth root is relatively strong and blunt, the extraction requires relatively strong move-ments to the bucca, back to the palate, and then in the buccoocclusal direction with a rotational, fractional force.
The maxillary first molar has three large and relatively strong roots. The buccal roots are usu-ally relatively close together, and the palatal root diverges widely toward the palate. If the two buccal roots are also widely divergent, it becomes difficult to remove this tooth by closed, or forceps, extraction. Once again the overlying alveolar bone is similar to that of other teeth in the max-illa; the buccal plate is thin and the palatal cortical plate is thick and heavy. When evaluating this tooth radio-graphically, the dentist should note the size, curvature, and apparent divergence of the three roots. Additionally the dentist should look carefully at the relationship of the tooth roots to the maxillary sinus. If the sinus is in close proximity to the roots and the roots are widely divergent, sinus perforation caused by removal of a portion of the sinus floor during tooth removal is increasingly likely. If this appears to be likely after preoperative evaluation, the surgeon should strongly consider a surgical extraction.
The paired forceps no. 53R and no. 53L are usually used for extraction of the maxillary molars . These two forceps have tip projections on the buccal beaks to fit into the buccal bifurcation. Some surgeons prefer to use the no. 89 and no. 90 forceps, which are sometimes called the upper cowhorn forceps. These two forceps are especially useful if the crown of the molar tooth has large caries or large restorations.
The upper molar forceps is adapted to the tooth and apically seated as far as possible in the usual fashion. The basic extraction movement is to use strong buccal and palatal pressures, with stronger forces toward the buccal than toward the palate. Rotational forces are not useful for extraction of this tooth because of its three roots. As mentioned in the discussion of the extraction of the maxillary first premolar, it is preferable to fracture a buccal root than a palatal root (because it is easier to retrieve the buccal roots). Therefore if the tooth has widely divergent roots and the dentist suspects that one root may be fractured, the tooth should be luxated in such a way as to prevent fracturing the palatal root. The dentist must minimize palatal force, because this is the force that fractures the palatal root. Strong, slow, steady, buccal pressure expands the buccocortical plate and tears the periodontal ligament fibers that hold the palatal root in its position. Palatal forces should be used but kept to a minimum.
The maxillary second molar's anatomy is similar to that of the maxillary first molar except that the roots tend to be shorter and Jess divergent, with the buccal roots more commonly fused into a single root. This means that the tooth is more easily extracted by the same technique described for the first molar.
The erupted maxillary third molar frequently has conic roots and is usually extracted with the no. 210S forceps, which is universal forceps used for both the left and right sides. The tooth is usually easily removed, because the buc-cal bone is thin and the roots are usually fused and conical. The erupted third molar is also frequently extracted by the use of elevators alone. It is important to clearly visualize the maxillary third molar on the preoperative radiograph, because the root anatomy of this tooth is quite variable and often small, dilacerated, hooked roots exist in this area. Retrieval of fractured roots in this area can be very difficult.
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