上颌磨牙近中颊根的寻找和扩通

目的：寻找并尽量扩通上颌磨牙近中颊根第二根管，统计其发生率及通畅率。方法：离体上颌磨牙11颗，开髓、拔髓，寻找并尽量扩通近中颊根第二根管即MB2，根管预备、充填，拍片。统计其发生及发现率。临床上对146颗上颌磨牙开髓、拔髓，寻找并尽量扩通近中颊根第二根管即MB2，根管预备，充填，拍片。结果：离体牙10颗，上颌第一磨牙近中颊根第二根管发现率为60％，通畅率为50％。94颗上颌第一磨牙，近中颊根第二根管发现率为44.68％.通畅率为29.78％，52颗上颌第二磨牙，发现率为11.53％，通畅率为7.69％。结论：上颌第一磨牙近中颊根第二根管的发生率较高，其寻找、定位及扩通尽管有一定的困难，临床医生仍应注意寻找，以提高上颌磨牙根管治疗的成功率。

Location and dilation of the second mesiobuccal canals in maxillary molars

PURPOSE: To Locate and dilate the second mesiobuccal canals(MB2) in clinical treatment and in extracted molars in maxillary molars. METHODS: 11 extracted maxillary molars were studied. MB2s were searched and dilate the canals were filled with gutta-percha and then x ray film were taken. 146 maxillary molars included 94 maxillary first molars and 52 maxillary second molars were attempted to locate and dilate for MB2.Then root canal treatment was carried out in molars and x ray film were taken. RESULTS: MB2 canal can be located in 60% and dilate 50% of 10 extracted maxillary first molars.MB2 canal can be located in 44.68 % and dilated in 29.78 % of maxillary first molars.MB2 canal can be in located in 11.53% and dilated in 7.69% of maxillary second molars. CONCLUSION: The occurence of MB2 is high in maxillary first molars. Although there are many difficulties in location and dilate of MB2, attempt should be conducted to explore in order to increase rate incidence of root canal therapy.