锥形束CT分析下颌第三磨牙阻生与相邻的第二磨牙牙根外收的关系

Analyzing the relationship between the mandibular third molars impaction and external root resorption of the adjacent second molars by cone beam CT

[目的]利用锥形束CT(CBCT)探讨下颌第三磨牙阻生与相邻第二磨牙牙根外吸收(ERR)的关系.[方法]收集2017—2019年就诊的142例患者共计262颗患牙的临床资料,对下颌第三磨牙阻生引起相邻第二磨牙ERR的相关因素进行分析.[结果]第二磨牙ERR的患病率为52.67%.不同性别和年龄第二磨牙ERR间差异均无统计学意义(P>0.05),第三磨牙阻生方向、阻生深度及倾斜角度的不同引起第二磨牙ERR间差异有统计学意义(P<0.001);不同性别、年龄、第三磨牙阻生方向、阻生深度和倾斜角度引起第二磨牙ERR的严重程度间差异均无统计学意义(P>0.05);第二磨牙ERR的严重程度与ERR发生部位无相关性(P>0.05);第三磨牙不同阻生深度与第二磨牙ERR发生部位间有相关关系(P<0.001).[结论]第二磨牙ERR发生部位取决于第三磨牙不同的阻生深度,第三磨牙中位阻生、水平阻生及倾斜角度在40°~80°时更易导致第二磨牙ERR的发生,建议临床上尽早预防性拔除.

OBJECTIVE Cone beam CT(CBCT)was used to investigate the relationship between mandibular third molars impaction and external root resorption(ERR)of the adjacent second molars.METHODS Clinical data of 142 patients with 262 affected teeth from 2017 to 2019 were collected,and the related factors of ERR of the adjacent second molars caused by impacted mandibular third molars were analyzed.RESULTS The prevalence of ERR in second molars was 52.67%.There was no statistical significance in ERR of second molars among different genders and ages(P>0.05).The difference of ERR of the second molars caused by the difference of impacted direction,impacted depth and tilt angle of the third molars has statistical significance(P<0.001).There was no statistical significance in the severity of ERR of the second molars caused by different genders,ages,impacted direction,impacted depth and tilt angle of the third molars(P>0.05).There was no correlation between ERR severity and ERR location of the second molars(P>0.05).The different impacted depth of the third molars was correlated with the ERR location of the second molars(P<0.001).CONCLUSION The location of ERR of the second molars depends on different impacted attempts of the third molars.ERR of the second molars is more likely to occur when the third molars are median impaction,horizontal impaction and tilt angle between 40°-80°.It is suggested that preventive extraction should be clinically carried out as soon as possible.