不同投照角度X线根尖片诊断下颌第一磨牙远中舌根的临床研究

Clinical evaluation of different angulation radiograph in diagnosing distolingual root of the mandibular first molar

目的评价不同投照角度X线根尖片诊断下颌第一磨牙远中舌根的作用。方法选择需行根管治疗的205颗下颌第一磨牙为研究对象。术前拍X线正位根尖片及近中20°～30°偏位根尖片,对比分析是否存在远中舌根。术中根据根管的弯曲情况把远中舌根分为3类。记录下颌第一磨牙牙根和根管的数量。结果术前X线正位、近中偏位根尖片判断48颗(48/205)下颌第一磨牙存在远中舌根,临床治疗中均确定有远中舌根,其余157颗下颌第一磨牙术中均未见远中舌根。远中舌根发生率为23.41%。48颗下颌第一磨牙远中舌根中,Ⅰ类根管22颗(45.83%);Ⅱ类根管17颗(35.41%);Ⅲ类根管9颗(18.75%)。205颗下颌第一磨牙106颗(51.70%)为3根管;98颗(47.80%)为4根管;1颗(0.48%)为5根管。结论术前多角度根尖片能准确诊断下颌第一磨牙远中舌根。

Objective To evaluate the effectiveness of different angle projection radiograph in diagnosing distolingual root of mandibular first molar. Methods A total of 205 mandibular first molars that needed endodontic treatment in vivo were selected. Routine preoperative radiograph was taken at a horizontal angles of 0 and at a horizontal angles of mesial 20-30 degrees. The results of the preoperative radiographic diagnosis were compared with the clinical findings. The distolingual root canals were divided into three types. Results In 205 mandibular first molars,48（23.41% ） distolingual roots were diagnosed by preoperative radiograph, which was confirmed by the clinical findings. In 48 distolingual roots,type I was 22 （45.83%）, type Ⅱ 17 （ 35.41% ）, type Ⅲ 9 （ 18. 75% ） .In 205 mandibular first molars, 106 （（51.70%） had three canals and 98 （47.80%） four canals. One（0.48%） had five canals. Conclusion Different angulation radiograph could accurately diagnose distolingual root in mandibular first molar.