提高下中切牙双根管检出率的方法学研究

目的:用5种不同方法对离体下颌中切牙的单、双根管发生率及根管形态走向进行分析,比较其在下颌中切牙双根管检出率方面的差异,为临床治疗提供依据。方法:收集新鲜拔除的下颌中切牙176颗,分别采用X线唇舌向摄片、肉眼下15#K型锉探查、根管显微镜下15#K型锉探查、螺旋CT扫描、离体牙横截面法进行观察。采用SAS6.12软件包对所得数据进行统计学分析,采用McNemar确切概率法对5种方法双根管检出率进行两两比较。结果:以离体牙横截面观察结果为金标准,176颗下颌中切牙的双根管率为9.66%,双根管均为唇舌向分根,其中Ⅱ型根管占4.55%,Ⅴ型根管占5.11%。其他方法双根管检出率分别为X线唇舌向摄片法0.00%、肉眼下15#K型锉探查法2.84%、根管显微镜下15#K型锉探查法4.76%、螺旋CT扫描法9.09%。对5种不同方法的观察结果进行列联系数γ的统计学分析显示,在下颌中切牙双根管的检出率方面,离体牙横截面观察法>螺旋CT扫描法>根管显微镜下15#K型锉探查法>肉眼下15#K型锉探查法>X线唇舌向摄片法。结论:下颌中切牙存在一定比例的双根管发生率,临床医师应高度重视舌侧根管的存在,避免遗漏。当临床上常用的X线唇舌向摄片法和肉眼法不能发现可疑双根管时,建议改用X线偏移投照牙片法或使用根管显微镜及螺旋CT扫描等辅助检查方法。

The methodological study of improving the detected rate of mandibular central incisor with two canals

PURPOSE: To investigate the detected rate and modality of multiple canals in mandibular central incisor by 5 different methods and to compare the results and differences among the methods,in order to provide give theoretical evidence of choosing right method and treatment in clinic.METHODS: 176 mandibular central incisors were examined by 5 different methods,including radiograph at a horizontal angle of 0,macrography 15#K-file,dental operative microscope,spiral CT scanning,and dental cross section.All statistical analysis was performed using SAS6.12 software package.Data of detected rate of these 5 methods were compared using McNemar exact probability test.RESULTS: The result of dental cross section was the key standard,the rate in 176 mandibular central incisor was 9.66% with two canals,of which 4.55% were type Ⅱ,5.11% were type Ⅴ.The detected rate of two-canal teeth was 0.00% by radiograph at a horizontal angle of 0,2.84% by macroscopy15# K-file,4.76% by dental operative microscope,and 9.09% by spiral CT scanning,respectively.The results from 5 methods were compared with each other by McNemar test to find out the difference.Validity of these 5 methods according to γ was dental cross section > spiral CT scanning > dental operative microscope > macroscopy 15#K-file > radiograph at a horizontal angle of 0.CONCLUSIONS: Some mandibular central incisors have two canals,the clinicians should pay more attention to avoid missing canals.When radiograph at a horizontal angle of 0 and macroscopy 15#K-file can’t effectively find two canals,we suggest using the other methods such as radiograph with an excursion angle,dental operative microscope and spiral CT scanning to make clear diagnosis.