不同矢状骨面型错中切牙冠根角的锥形束CT分析  

Crown-root angle of the central incisors in skeletal ClassⅠ,Ⅱ,and Ⅲ malocclusions assessed with cone-beam computed tomography

作　　者：邹晨[1] 陈奕嘉[1] 吴志辉[1] 张雪铮[1] 朱双林[1] 

机构地区：[1]中山大学光华口腔医学院·附属口腔医院,广东省口腔医学重点实验室,广州510055

出　　处：《中华口腔医学研究杂志（电子版）》2013年第2期44-47,共4页Chinese Journal of Stomatological Research(Electronic Edition)

摘　　要：目的研究通过锥形束计算机体层摄影术(CBCT)比较Ⅰ、Ⅱ、Ⅲ类矢状骨面型错患者恒中切牙冠根角(CRA)的差异。方法于已拍摄CBCT及X线头颅侧位片的恒牙列期错患者中,按ANB角大小分类,随机选取矢状骨面型错患者Ⅰ类27例、Ⅱ类22例、Ⅲ类21例,垂直骨面型皆为均角型。利用Ez3D2009软件进行影像的三维重建并获得右侧中切牙的正中矢状切面图像,Auto CAD软件测量牙冠长轴与牙根长轴的交角(冠根角),进行统计分析。结果不同矢状骨面型错患者中切牙CRA差异有统计学意义(P<0.05);上颌中切牙CRA分别为(180.50±3.12)°、(178.73±3.66)°、(180.54±3.61)°;下颌中切牙CRA分别为(177.37±2.74)°、(178.85±3.50)°、(176.14±3.74)°。Ⅱ类矢状骨面型错上颌中切牙CRA小于Ⅰ、Ⅲ类,Ⅲ类矢状骨面型错下颌中切牙CRA小于Ⅱ类,差异均有统计学意义。结论不同矢状骨面型患者中切牙CRA差异均有统计学意义,Ⅱ类患者上颌中切牙及Ⅲ类患者下颌中切牙存在明显的CRA成角现象,牙冠相对牙根舌倾。Objective To test the null hypothesis the crown-root angle （CRA） of central incisors was not different among patients with skeletal ClassⅠ, Ⅱ, and Ⅲ malocclusions by cone-beam computed tomography （CBCT）. Methods Patients taken CBCT and lateral cephalometric images with normal vertical patterns were classified according to ANB angle. ClassⅠ comprised 27 patients, ClassⅡ comprised 22 patients, ClassⅢ comprised 21 patients. Three-dimensional reconstructed images were made by using the Ez3D2009 software. The median sagittal planes of all the right central incisors were selected and then analyzed by the Auto CAD software. The CRA was measured. Results Significant differences in the crown-root angle of central incisors were shown in different sagittal skeletal patterns groups（P 〈 0.05）. The mean CRA of upper central insiors in ClassⅠ,Ⅱ,Ⅲ groups were （180.50 ± 3.12）°,（178.73 ± 3.66）°,（180.54 ± 3.61）°, and ClassⅡ 〈 Class I , ClassⅡ 〈 ClassⅢ （P 〈 0.05）. The mean CRA of lower central incisors in ClassⅠ,Ⅱ,Ⅲ groups were （177.37 ± 2.74）°, （178.85 ± 3.50）°, （176.14 ± 3.74）°, and ClassⅢ 〈 ClassⅡ（P 〈 0.05）. Conclusions Significant differences in the CRA of central incisor teeth were found among subjects with skeletal ClassⅠ,Ⅱ, and Ⅲ malocclusions. The CRA of upper central incisors in skeletal ClassⅡ and lower central incisors in skeletal Class Ⅲ was significant different, with the crown torqued lingual to the root axis.

关 键 词：矢状骨面型 中切牙 冠根角 锥形束计算机体层摄影术 

分 类 号：R783.5[医药卫生—口腔医学]