Objective To evaluate the incidence of two-rooted mandibular premolar morphology using full-mouth periapical film series in a Chinese population,with particular emphasis on bilateral incidence,so as to provide a clini...Objective To evaluate the incidence of two-rooted mandibular premolar morphology using full-mouth periapical film series in a Chinese population,with particular emphasis on bilateral incidence,so as to provide a clinical anatomical basis for root canal treatment in mandibular premolars.Methods A total of 2015 patients who underwent dental treatment and had full mouth periapical radiographs at the Peking University School of Stomatology from April 2011 to April 2012 were enrolled in this study.Three experienced dentists reviewed the patients' periapical films and classified the root morphology of mandibular premolars bilaterally.The incidence of unilateral and bilateral double roots were recorded and calculated,including confirmed and suspected bucco-lingual root types.Results In terms of the morphology of two-rooted mandibular first premolars,of the 2015 cases with complete root formation,two-rooted first premolars were detected in 120 cases,with a total number of 159 teeth.According to the number of teeth,the overall incidence of double roots was 4.03%(159/3972).In terms of the morphology of two-rooted mandibular second premolars,of the 2015 cases with complete root formation,two-rooted second premolars were detected in 24 cases,with a total number of 33 teeth.According to the number of teeth,the overall incidence of double roots was 0.85%(33/3880).Conclusions The roots of mandibular premolars display specific morphological patterns.Based on a large sample,we observed and calculated not only the occurrence rate of bucco-lingual and mesio-distal double roots in first and second mandibular premolars,but also the incidence of unilateral or bilateral double roots within the same mandible.These findings could provide useful information on the anatomical structure of mandibular premolars for endodontic,prosthodontic and surgical procedures,and could improve the quality of treatment and reduce complications.展开更多
目的:探讨40岁以上单根管下颌第二前磨牙根尖段根管直径和锥度。方法:收集40岁以上单根管下颌第二前磨牙52颗,采用显微CT进行扫描,利用3D Med 2.2软件重建后,分别对距离解剖性根尖孔1,2,3,4,5 mm处进行根管颊舌向和近远中向直径测量,并...目的:探讨40岁以上单根管下颌第二前磨牙根尖段根管直径和锥度。方法:收集40岁以上单根管下颌第二前磨牙52颗,采用显微CT进行扫描,利用3D Med 2.2软件重建后,分别对距离解剖性根尖孔1,2,3,4,5 mm处进行根管颊舌向和近远中向直径测量,并计算颊舌向、近远中向锥度和观测根管横截面形态变化。结果:根管根尖段平均直径颊舌向大于近远中向(P<0.05),颊舌径和近远中向平均锥度分别为0.09±0.10,0.05±0.03,根尖段80%根管形态为椭圆形。结论:单根管下颌第二前磨牙根尖段个体差异大,颊舌向直径和锥度均大于近远中向,常用根管器械难以兼顾所有根管,根管预备时需引起注意。展开更多
文摘Objective To evaluate the incidence of two-rooted mandibular premolar morphology using full-mouth periapical film series in a Chinese population,with particular emphasis on bilateral incidence,so as to provide a clinical anatomical basis for root canal treatment in mandibular premolars.Methods A total of 2015 patients who underwent dental treatment and had full mouth periapical radiographs at the Peking University School of Stomatology from April 2011 to April 2012 were enrolled in this study.Three experienced dentists reviewed the patients' periapical films and classified the root morphology of mandibular premolars bilaterally.The incidence of unilateral and bilateral double roots were recorded and calculated,including confirmed and suspected bucco-lingual root types.Results In terms of the morphology of two-rooted mandibular first premolars,of the 2015 cases with complete root formation,two-rooted first premolars were detected in 120 cases,with a total number of 159 teeth.According to the number of teeth,the overall incidence of double roots was 4.03%(159/3972).In terms of the morphology of two-rooted mandibular second premolars,of the 2015 cases with complete root formation,two-rooted second premolars were detected in 24 cases,with a total number of 33 teeth.According to the number of teeth,the overall incidence of double roots was 0.85%(33/3880).Conclusions The roots of mandibular premolars display specific morphological patterns.Based on a large sample,we observed and calculated not only the occurrence rate of bucco-lingual and mesio-distal double roots in first and second mandibular premolars,but also the incidence of unilateral or bilateral double roots within the same mandible.These findings could provide useful information on the anatomical structure of mandibular premolars for endodontic,prosthodontic and surgical procedures,and could improve the quality of treatment and reduce complications.
文摘目的:探讨40岁以上单根管下颌第二前磨牙根尖段根管直径和锥度。方法:收集40岁以上单根管下颌第二前磨牙52颗,采用显微CT进行扫描,利用3D Med 2.2软件重建后,分别对距离解剖性根尖孔1,2,3,4,5 mm处进行根管颊舌向和近远中向直径测量,并计算颊舌向、近远中向锥度和观测根管横截面形态变化。结果:根管根尖段平均直径颊舌向大于近远中向(P<0.05),颊舌径和近远中向平均锥度分别为0.09±0.10,0.05±0.03,根尖段80%根管形态为椭圆形。结论:单根管下颌第二前磨牙根尖段个体差异大,颊舌向直径和锥度均大于近远中向,常用根管器械难以兼顾所有根管,根管预备时需引起注意。
