成人骨性Ⅲ类错下前牙冠根形态的锥形束CT分析  

Crown-root morphology of mandibular anterior teeth:a cone-beam computed tomography study on adult skeletal Class Ⅲ malocclusion

作　　者：王博[1] 房兵[1] 张莉[1] 

机构地区：[1]上海交通大学医学院附属第九人民医院.口腔医学院口腔颌面外科上海市口腔医学重点实验室,上海200011

出　　处：《中国口腔颌面外科杂志》2011年第6期472-476,共5页China Journal of Oral and Maxillofacial Surgery

基　　金：国家自然科学基金(10972142);上海市科学技术委员会资助项目(08411961600)~~

摘　　要：目的:借助锥形束CT(cone-beam computed tomography,CBCT)结合计算机辅助测量技术,描述研究成人骨性Ⅲ类错下前牙的冠根形态,为此类错畸形的临床治疗提供指导。方法:2008年1月—2010年12月于上海交通大学附属第九人民医院口腔颌面外科正颌-正畸联合诊治门诊中心寻求正畸治疗的成人连续病例中,选取诊断为骨性I类及Ⅲ类的错畸形各30例(以下简称为I类组及Ⅲ类组),按照矢状向骨性不调的严重程度,将Ⅲ类组分为轻、中、重度3类。以I类组作为对照,应用CBCT,从角度、线距两方面比较Ⅲ类组下前牙的冠根形态,评价其是否与错畸形的严重程度有关。采用SAS8.02软件包对数据进行统计学处理,成组t检验分别比较Ⅲ类组与I类组之间轻、中、重度Ⅲ类组与I类组间下前牙冠根角度及冠根偏移距离的差异。结果:I类组下前牙冠根角度平均为175.39°,冠根偏斜距离平均为0.70mm;Ⅲ类组下前牙冠根角度平均为172.40°,冠根偏斜距离平均为1.1514mm,下前牙的冠根形态较之I类组差异有统计学意义。轻度骨性Ⅲ类错(以下简称为轻度Ⅲ类组)前牙冠根角度平均为173.36°,冠根偏斜距离平均为0.99mm;中度骨性Ⅲ类错(以下简称为中度Ⅲ类组)下前牙冠根角度平均为173.27°,冠根偏斜距离平均为1.01mm;较之I类组,下前牙冠根形态的差异均无统计学意义。重度骨性Ⅲ类错(以下简称为重度Ⅲ类组)下前牙冠根角度平均为171.03°,冠根偏斜距离平均为1.38mm,较之I类组,下前牙冠根形态有显著差异。结论:重度成人骨性Ⅲ类错畸形下前牙存在明显的冠根成角现象,牙冠相对牙根明显舌倾。提示此类患者的正颌-正畸联合治疗,下前牙移动的理想位置应由牙根而不是牙冠的位置决定。PURPOSE： To investigate the mandibular anterior teeth crown-root morphology of adult skeletal Class Ⅲ malocclusion with the help of CBCT.METHODS： The sample consisted of 60 cases seeking orthodontic or surgical-orthodontic treatment in the Center of Craniofacial Orthodontics of Ninth People＇s Hospital during 2008.1-2010.12.Class I group comprised 30 cases with skeletal Class I malocclusion,Class Ⅲ group comprised 30 cases with skeletal Class Ⅲ malocclusion.Furthermore,Class Ⅲ group was divided into mild,moderate and severe type according to the sagittal skeletal discrepancy.Class I malocclusion was used as the control group,mandibular anterior teeth crown-root morphology of Class Ⅲ group was compared with Class I group with the help of CBCT.Data was processed with SAS8.02 software package and independent samples t test was employed for comparison of linear and angular measurements.RESULTS： Crown-root angle and incisor edge deviation distance were 175.39° and 0.70mm for mandibular anterior teeth in Class I group,which were 172.40° and 1.15mm in Class Ⅲ group,significant difference was observed between the two grouFurthermore,crown-root angle and incisor edge deviation distance were 173.36° and 0.99mm for mandibular anterior teeth in mild skeletal Class Ⅲ type,which were 173.27° and 1.01mm in moderate type,there was no significant differences in crown-root morphology between mild or moderate skeletal Class Ⅲ malocclusion and the control group.For mandibular anterior teeth of severe skeletal Class Ⅲ malocclusion,crown-root angle was 171.036° and incisor edge deviation distance was 1.38 mm,significant difference was observed in crown-root morphology compared with the control group.CONCLUSION： Severe adult skeletal Class Ⅲ malocclusion exhibited significant crown-root morphology compared with skeletal Class I malocclusion.Special attention should be paid to the position of lower anterior teeth roots during surgical-orthodontic treatment for adult severe skeletal Class Ⅲ malocclusio

关 键 词：骨性Ⅲ类错 成人 冠根形态 锥形束CT 

分 类 号：R783.5[医药卫生—口腔医学]