Maxillary first premolar
The maxillary first premolar 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 (Fig. 7-62). 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 instrument of choice. Alternatively, the (no. 150) 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 relatively 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 prevent 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 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 pressure, any rotational force. should be avoided. Final delivery of the tooth from the tooth socket is with traction force in the occlusal direction and slightly buccal (see Fig, 7-62).