目的　通过分段测量骨性Ⅲ类错牙合　畸形患者上下牙列牙弓内所有牙齿（除第三磨牙）的轴倾角和转矩角,评价牙冠、牙根及全牙位置指标间的关系。  方法　选取符合纳入标准的29 例成人骨性Ⅲ类错牙合  患者，拍摄CBCT并收集其Dicom数据，利用Invivo5.1软件对上、下颌各牙的牙冠、牙根、全牙的转矩角和轴倾角进行测量。   结果　(1)骨性Ⅲ类错牙合 ，上、下牙列冠、根及全牙轴倾角一致性较好，两两比较，P>0.05。(2)骨性III类错牙合  ，在全牙列的转矩角中，上牙列冠、根及全牙的一致性较好，两两比较，P>0.05，而下牙列除磨牙外所有牙齿冠、根倾斜存在统计学差异，P<0.05，牙根与牙体长轴方向及程度较一致，差异无统计学差异，P>0.05。  结论　  (1)骨性Ⅲ类错牙合  牙冠的倾斜角度与牙根或全牙的倾斜角度的一致性不高，可能存在牙体位置判别误差；(2)牙根倾斜程度与全牙倾斜程度较一致。

Objective　To investigate the relationship among the crown, root and the whole tooth position and to provide technical and data support for the future in-depth study.　Methods　29 adult skeletal Class III malocclusion patients who met the inclusion criteria were selected. They all were shot Cone-beam CT（CBCT）and the DICOM data were collected. The tilt angle and torque angle of all teeth (except the third molar) in the upper and lower jaws in skeletal Class III were measured respectively by the software Invivo5.1. Results　(1) In skeletal Class III malocclusion, there was a good consistency among the tooth crown, root and the whole tooth tip angles in the upper and lower jaws（P>0.05）. (2) In skeletal Class III malocclusion, there was a good consistency among the upper teeth crown, root and the whole teeth torque angles（P>0.05）. However there were great differences between the crown and the root torque angles in lower teeth except for the first molar（P<0.05）. And torque angles between the root and whole tooth were consistent in lower jaw (P>0.05).　Conclusions　(1) In skeletal Class III malocclusion, there is low consistency between the tilt angle of the crown and the root or the whole tooth, which may be ascribed to the discrimination error of the tooth position; (2) There is a good consistency between the tilting grade of the root and that of the whole tooth.