下颌第一恒磨牙髓腔解剖标志与近中中央根管发生率间关系的CBCT研究

The association between the anatomic landmarks of the pulp chamber and the prevalence of middle mesial canals in mandibular first molars:A cone-beam computed tomography study

目的运用锥形束CT(CBCT)探讨下颌第一恒磨牙(MFM)近中中央根管(MMC)的根管形态和发生率,研究相关髓腔解剖标志与MMC发生率间的关系,为临床牙髓治疗提供参考。方法选取1000例患者的影像学资料,共计1785颗MFM符合纳入标准。记录如下内容:年龄、性别、牙位、远舌根存在与否、近中颊侧根管(MB)和近中舌侧根管(ML)两根管口之间的距离。使用SPSS 20.0统计软件对所有数据进行分析。结果MMC在MFM的发生率为8.12%(145/1785),其中,具有独立根尖孔的MMC发生率为0.84%(15/1785);<40岁组发生率为9.99%(82/821),≥40岁组MMC的发生率为6.54%(63/964),P<0.05;男性MMC的发生率(7.12%,67/941)稍低于女性(9.24%,78/844),P>0.05;左侧MFM的MMC发生率(8.34%,76/911)略高于右侧(7.89%,69/874),P<0.05;存在远舌根时,MMC的发生率(8.85%,41/463)较不存在远舌根时(7.87%,104/1322)稍高,P>0.05;当MMC存在时,MB-ML的根管口间距离为(2.99±0.44)mm,当不存在MMC时,该距离为(3.39±0.49)mm,P<0.05。结论下颌第一恒磨牙髓腔解剖标志可辅助预测MMC是否存在,减少MMC的遗漏并防止对牙齿结构的过度切削。

Objective Using cone beam computed tomography(CBCT),this paper discussed the morphology and incidence of middle mesial root canal(MMC)of mandibular first molar(MFM),and evaluated the relationship between the related factors and the incidence of MMC,in order to provide reference for clinical treatment.Methods CBCT imaging data were collected for each patient who met the inclusion criteria.The following were recorded:age,gender,the tooth position,the distance between the mesiobuccal(MB)and mesiolingual(ML)orifices,and the existence of the radix entomolaris.Alldata were analyzed by SPSS20.0 statistical software.Results The incidence of MMC in MFM was 8.12%(145/1785);among them,fused MMC was the most common with an incidence of only 0.84%(15/1785).The incidence of MMC in people older than 40 years old was 9.99%(82/821)and 6.54%(63/964)in people under 40 years old,P<0.05.The incidence of MMC in males(7.12%,67/941)was slightly lower than that in females(9.24%,78/844),P>0.05.The incidence of MMC in left MFM(8.34%,76/911)was slightly higher than that in right side(7.89%,69/874),P<0.05.The incidence of MMC was slightly higher in the radix entomolaris group(8.85%,41/463)than in the non-radix entomolaris group(7.87%,104/1322),P>0.05.The distance between MB-ML root orifices was(2.99±0.44)mm in non-MMC group,(3.39±0.49)mm in MMC group,P<0.05.Conclusion The anatomical markers of the pulp chamber of mandibular first molars can help to predict the presence of MMC.Understanding these anatomical landmarks can help physicians reduce missed MMC and prevent excessive cutting of dental structures during clinical practice.