影响口腔正畸治疗患者下颌第三磨牙状态改变的因素分析  

Factors influencing the changes of lower third molars' angulation and space/crown width ratio by orthodontic treatment

作　　者：李小彤[1] 张东妹[2] 杨雁琪[3] 

机构地区：[1]北京大学口腔医学院·口腔医院正畸科,北京100081 [2]河北省保定市第一中心医院,保定071051 [3]香港大学牙科学院正畸科,中国香港特别行政区999077

出　　处：《北京大学学报（医学版）》2011年第2期267-271,共5页Journal of Peking University:Health Sciences

摘　　要：目的：研究影响口腔正畸患者治疗前、后下颌第三磨牙状态改变的因素。方法：利用正畸治疗前、后的全口曲面断层片,测量120例正畸患者的120颗下颌第三磨牙[男37例,女83例,年龄在1024岁,平均（14.1±3.3）岁]前倾角度和间隙/宽度比值的改变,统计分析影响正畸治疗前、后改变的因素。结果：（1）正畸治疗前、后下颌第三磨牙前倾角度和间隙/宽度比值的改变个体差别较大;（2）影响正畸治疗前、后下颌第三磨牙前倾角度和间隙/宽度比值改变的因素主要有拔牙、下颌平面角、治疗前的前倾角度和间隙/宽度比值（P〈0.05）,而骨龄和牙龄等因素对下颌第三磨牙状态的影响差异无统计学意义;（3）Logistic回归分析,进入治疗后下颌第三磨牙前倾角度是否〈30°判别方程的因素有拔牙、下颌平面角和治疗前的前倾角度,其中拔牙状况影响程度较大,拔牙使得治疗后的前倾角度〈30°（直立倾向）的可能性更大,是不拔牙的4.210倍。结论：正畸拔牙治疗有助于下颌第三磨牙的直立,并使其萌出间隙增大;第三磨牙治疗前的状况（前倾角度和间隙/宽度比值）也是影响治疗后改变的重要因素;下颌平面角度小的患者预后下颌第三磨牙直立的可能性增加。Objective： To investigate the factors which influence the changes of lower third molars＇ angulation and space/crown width ratio by orthodontic treatment.Methods： Pretreatment and posttreatment panoramic radiographs of 120 orthodontically treated cases were taken.The lower third molars＇ angulation and space/crown width ratio were examined and the relative factors on changes were analyzed.Results：（1）The changes of the lower third molars＇ angulation and space/crown width ratio after orthodontic treatment were quite different among the cases.（2）The factors which influenced these changes mainly included extraction,mandibular plane angle,angulation and space/crown width ratio of lower third molar before orthodontic treatment.（3） Extraction was the most significantly variable associated with lower third molars＇ upright（angulation 〈30°） after orthodontic treatment.Conclusion： Orthodontic extraction is helpful to upright the lower third molars and to increase the space for third molars;and the pre-treatment lower third molars＇ angulation and space/crown width ratio are important variables for the changes after treatment;cases with lower mandibular plane angle are apt to greater possibility for the lower third molars＇ upright.

关 键 词：正畸学 磨牙 第三 拔牙 放射摄影术 全景 

分 类 号：R783.5[医药卫生—口腔医学]