Fig. 48.
In cases where the crowding is not so great, and the tooth is more in the normal line of the arch, a forceps with a narrow outer blade will suffice ([fig. 46]). Extractive force should be used principally towards the median line of the mouth, and this may be combined with slight rotary movement.
Fig. 49.
(g) Impacted Lower Third Molars are amongst the most difficult teeth to extract. Where the tooth is deep-seated, the gum should be pushed aside by careful packing, and as clear a view of the tooth as is possible obtained. For removing these teeth it is difficult to give any rules, as each case must be treated on its own merits.
As useful an instrument as any for their removal is a curved elevator ([fig. 49]), the blade of which can often be inserted under the crown, and assuming that good leverage is thus obtained, the tooth can be prised up. Sometimes the tooth is firmly embedded in the bone. In such cases a clear view of the tooth may be obtained by gradually packing the soft tissues apart, the periosteum covering the alveolus should then be raised, and the bone surrounding the tooth cut away with suitable instruments. The tooth, when freely exposed, should be removed with an elevator or forceps.
The wound resulting must be carefully packed and treated as described on page 85.
CHAPTER IV.
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The Use of Anæsthetics during Extraction of the Teeth.
The anæsthetics used during the extraction of teeth may be divided into two classes, viz.:—general and local. It is not proposed to make any allusion to the methods of administering general anæsthetics, as they hardly fall within the scope of this volume. There are, however, a few points which the operator should bear in mind when employing them and which may with advantage be briefly dwelt upon, but before considering these, a word or two may not be out of place with regard to the choice of the anæsthetic. In dental practice three agents are generally used, nitrous oxide alone or in combination with air or oxygen, ether and chloroform.