The mandibular molars are usually two rooted, with. roots of the first molar more wide divergent than those of the· second molar. Additionally the roots may converge at the apical one third, which increases the difficulty of extraction. The roots are generally heavy and strong. The overlying .alveolar bone is heavier than the bone on any other teeth in the mouth. The combination of relatively long, strong, divergent roots with heavy overlying buccolingual bone makes the mandibular first molar the most difficult of all teeth to extract.
The no. 17 forceps is usually used for extraction of the mandibular molars; it has small tip projections on both beaks to fit into the bifurcation of the tooth roots. The forceps is adapted to the root of the tooth in the usual fashion, and strong apical pressure is .applied to set the beaks of the forceps apically as far as possible. Strong buccolingual motion is then used to expand the tooth socket and allow the ‘tooth to be delivered in the buccoocclusal direction. The linguoalveolar bone around the second molar is thinner than the buccal plate, so the second molar can be more easily removed with stronger lingual than buccal pressures (Fig. 7-70).
If the tooth roots are clearly bifurcated, the no. 23, or ( )whom, forceps can be used. This instrument is designed to be closed forcefully with the handles, there by squeezing the beaks of the forceps into the bifurcation. This creates force against the crest of the alveolar ridge on the buccolingual aspects and literally forces the tooth superiorly directly out of the tooth socket (Fig. 7-71).If initially this is not successful, the forceps is given buccolingual movements to expand the alveolar bone, and more squeezing of the handles is performed. Care must be taken with these forceps to prevent damaging the maxillary teeth, because the lower molar may actually pop out of the socket and thus release the forceps to strike the upper teeth (see Fig. 7-71).
Erupted mandibular third molars usually have fused conical roots. Because a bifurcation is not likely, the no. 222 forceps-a short-beaked, right-angled forceps-is used to extract this tooth. The lingual plate of bone is definitely thinner than the buccocortical plate, so most of the extraction forces should be ‘delivered to the lingual aspect. The third molar is delivered in the linguloocclusal direction. The erupted mandibular third molar that is in function can be a ‘deceptively difficult tooth to extract.
The dentist should give serious consideration to using the straight elevator to achieve a moderate degree of luxation before applying the forceps. Pressure should be gradually increased, and attempts to mobilize the tooth should be made before final strong pressures are delivered.