a b c d
Fig. 21.
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(a) Normal upper first permanent molar. (b) Oblique rooted upper first permanent molar. (c) Normal upper second permanent molar. (d) Oblique rooted second permanent molar. |
There is an abnormality of the upper molars which may with advantage be mentioned here. In this deformity the posterior buccal root is situated in a plane much internal to the anterior—in other words, it is an exaggeration of the normal arrangement. Such teeth have been termed by Mr. Booth Pearsall “oblique rooted” ([fig. 21]). The abnormality is met with most frequently in the third molar, sometimes in the second, rarely in the first. The difficulty encountered in extracting these teeth is that the outer blade of the forceps tends to slip round. Oblique-rooted teeth can at times be diagnosed by noting an undue prominence of the alveolus over the anterior buccal root, and are best removed with forceps similar to that shown in [fig. 20].
In cases where a portion of the crown remains and the decay extends well below the gum on either the palatal or buccal side, ordinary molar forceps should be discarded and root forceps employed; useful patterns are shown in [figs. 18], [ 22] and [23]. The removal of teeth in this condition is carried out as follows, and for the sake of description it will be supposed that the decay extends deeply on the palatine side. One blade of the forceps should be first applied to the buccal side of the tooth and to the root which is considered the stronger; the inner blade should then be applied to the palatine root care being taken to insinuate it between the alveolus and the root. The forceps should then be pushed well upwards until a firm hold of the root is obtained. A firm inward movement should then be made, as this will allow the inner blade to pass still higher up the palatine fang and insure steadiness should the blades tend to ride upon the surface of the root. An outward movement should next be made, but to nothing like so great a degree as that used in extracting molars with the whole of the crown standing. This inward and outward movement is to be repeated until the tooth is freed, the force being principally applied in the inward direction.
Fig. 22.