上颌第二磨牙近中颊根第二根管的解剖定位

Location of the second mesiobuccal root canal in maxillary second molars

目的:观察髓室底的解剖形态和根管口的数目和位置,探寻近颊根第二根管(MB2)根管口的定位规律。方法:选择■离体牙220颗,利用耳鼻喉科内窥镜系统对髓室底进行观察,测量髓室底根管口之间的位置关系,统计MB2出现率,探寻MB2根管口定位规律。结果:髓室底观察发现,MB2基本上发生在MB-P连线的近中舌侧,MB2的发生率为38.2%。MB2-MB的距离为(1.56±0.65)mm。MB-DB的距离为(2.34±0.78)mm,MB-P的距离为(5.05±1.26)mm。∠MB2-MB-P的角度为(22.21±10.35)°。结论:MB2根管口多位于MB-P连线的近中舌侧,且在以MB为中心,MB-P为一边,向近中做角度为(22.21±10.35)°的扇形范围内基本上能找到MB2。

Objective：To investigate the anatomical features of the pulp-chamber floor and the number of the root canal orifice,to explore the map of locating MB2 root canal orifice.Methods：The pulp floor in maxillary second molars were observed and measured under the endoscope.Analyzed the factors that influence the ability to locating the negotiation of MB2 canal with ENT endoscopy.Results：MB2 orifice was usually located mesially along MB-P line.MB2 canal was located in 38.2% frequency,the distance between MB and MB2 orifices was（1.56±0.65）mm,between MB and DB orifices was（2.34±0.78）mm,between MB and P orifices was（5.05±1.26）mm;the angle of P-MB and MB-MB2 was（22.21±10.35）°.Conclusion：MB2 orifice usually locates at 22.21°from the angle of P-MB and MB-MB2.