(_e_) =Lower Central Incisors= placed similarly to that shown in fig. 43 may be removed with ordinary lower root forceps (hawk’s-bill pattern), the blades being placed on the mesial and distal surfaces of the root, and movement applied in a direction to and away from the median line of the mouth. When the crowding is not so extreme as shown in fig. 44, forceps of the hawk’s-bill pattern with a strong but narrow inner blade should be used (fig. 45), and the principal extractive movement made in an outward direction. For an incisor placed as shown in fig. 47, the narrow blade should be the outer one (fig. 46), and the principal force should be applied in an inward direction. (_f_) =Lower Bicuspids= placed as in fig. 48 are [Illustration: FIG. 45.] [Illustration: FIG. 46.] most difficult teeth to remove. One of the most useful instruments for their extraction is a pair of upper root forceps (Read’s pattern, fig. 22), which should be held so that the curve of the blades is downwards. The blades should grasp the root on its anterior and posterior surfaces. Slight rotary movement may first be attempted, followed by lateral motion. These movements may be persevered with until the tooth is found to yield. Too much haste may lead to a fracture, which would be extremely difficult to deal with. [Illustration: FIG. 47.] [Illustration: 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. [Illustration: 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. The Use of Anæsthetics during Extraction of the Teeth.