锥形束CT对青少年颌骨硬组织三维测量的可行性分析

Feasibility study on CBCT for 3-D measurement of craniofacial skeletal asymmetry in teenagers

目的分析锥形束CT三维重建后颅颌骨解剖标志点定点准确度,评价锥形束CT对青少年颌骨硬组织三维不对称性测量的可行性。方法选择青少年自愿者47名,拍摄锥形束CT并三维重建后,确定解剖标志点,比较两名不同观测者定位解剖标志点的差异性。结果所确定的23个标志点中,除眶下点、下颌角点外,都表现出了良好的可重复性,坐标值差异均数（x）〈2 mm;其中颅底点、蝶鞍中心点、鼻根点、前鼻嵴点、髁突顶点、喙突顶点坐标定位差异度〈1 mm,眶下缘点、下颌角点定位存在微小误差,坐标差异值为2～3 mm。结论利用锥形束CT定位青少年颌骨硬组织解剖标志点定位准确,可重复性好,能以此建立三维参考平面,用于颌骨硬组织三维测量。

Objective To analyze the anatomic landmarks fixed-point accuracy of by eraniofacial skeleton atter the 3-D reconstruction by cone-beam computer tomography （CBCT）, and to evaluate feasibility of CBCT for the 3-D measurement of eraniofacial skeletal asymmetry. Methods 47 teenage volunteers were selected and received CBCT examination and the 3-D reconstruction. The anatomic landmarks were determined. Comparison was made in the differences in the landmarks between two observers. Results The 23 landmarks, except infraorbital point and gonion, all showed good repeatability. The average difference value of coordinate was 〈 2 ram. The coordinate difference of basion, sella tureiea center, nasion, front nasal （：rest, condylar process vertex, and coracoid vertex was 〈1 mm. The localization of infraorbital point and gonion had minute error, and the coordinate difference value was 2-3 mm. Conclusion Anatomic landmarks of craniofaeial skeleton in teenagers can be positioned accurately and reproductively by CBCT, which ean help to establish the 3-D plane of reference in order to make the 3-D measurement of eraniofacial skeleton.