1Weine FS,Healy HJ,Gerstein H,et al.Canal configuration in the mesiobuccal root of the maxillary frist molar and its endodontic significance.Oral Surg Oral Med Oral Pathol,1969,28:419 -425.
2Weller RN,Hartwell GR.The impact of improved access and searching techniques on detection of the mesiolingual canal in mxillry molats.J Endodont,1989,15(2):82.
3Wolcott J, Ishley D, et al. Clinical investigation of second mesiobuccal canal in endodontically treated and retreated maxillary molars. J Endod, 2002,28(6):477 - 479.
4Stropko JJ. Canal morphology of maxillary molars: clinical observations of canal configurations. J Endod, 1999, 25 (6) : 446 -450.
5Weller RN, Hartwell GR. The impact of improved access and searching techniques on detection of the mesiolingual canal in maxillary molars. J Endod, 1989,15(2) :82-83.
8Hartwell G,Appelstein CM, Lyons WW, et al. The incidence of four canals in maxillary first molars: a clinical determination [ J ]. JAm Dent Assoc,2007,138 ( 10 ) : 1344 - 1346.
9Vemm P, Love RM. A Micro CT study of the mesiobuccal root ca- nal morphology of the maxillary first molar tooth [ J ]. lnt Elutod J,2011,44(3) : 210 -217.
10Zhang R,Yang H,Yu X, et al. Use of CBCT to identify the mor- phology of maxillary permanent molar teeth in a Chinese subpop- ulation [ J ]. Int Endod J, 2011,44 ( 2 ) : 162 - 169.
