Goel N K, Gill K S, Taneja J R
Government Dental College and Hospital, Amritsar, Punjab.
J Indian Soc Pedod Prev Dent. 1991 Mar;8(1):12-4.
The number and configuration of root canals in mandibular first permanent molar, studied by radiographic method, on 60 teeth revealed (1) one canal in the mesial root in 5 percent, two in 78.3 percent, three in 13.3 percent and four in 3.3 percent. In distal root, one canal was observed in 58.3 percent, two in 40 percent and three in 1.7 percent of the cases; (2) transverse anastomosis existed in about half of the mesial roots; whereas in distal root, it was only 21.7 percent; (3) biconvex canal curvature was seen in 18.3 percent of mesial and 1.7 percent of distal roots (4) apical foramina: in mesial root two apical foramina were observed in 60 percent of specimens, three in 6.7 percent and four in 3.3 percent. In distal root, two apical foramina were seen in 25 percent and three in 1.7 percent cases; (5) type of root canal: type 2-1 was the most common feature of mesial as well as distal roots; (6) the mesial root canals tended to be curved in 51.7 percent, while distal root canal straight in 58.3 percent.
通过影像学方法对60颗下颌第一恒磨牙的根管数量和形态进行研究，结果显示：（1）近中根中，1个根管的占5%，2个根管的占78.3%，3个根管的占13.3%，4个根管的占3.3%。远中根中，1个根管的占58.3%，2个根管的占40%，3个根管的占1.7%；（2）约半数近中根存在横向吻合；而远中根中仅为21.7%；（3）18.3%的近中根和1.7%的远中根可见双凸形根管弯曲；（4）根尖孔：近中根中，60%的标本观察到2个根尖孔，6.7%观察到3个，3.3%观察到4个。远中根中，25%的病例观察到2个根尖孔，1.7%观察到3个；（5）根管类型：2-1型是近中根和远中根最常见的特征；（6）51.7%的近中根管有弯曲倾向，而58.3%的远中根管是直的。
