面部软组织直接和间接三维定点方法的对比分析

Comparison of direct and indirect three-dimensional placement methods of facial soft tissue

目的 比较面部三维软组织测量中直接定点法与间接定点法的可靠性及可重复性,为软组织评价体系的建立和完善提供依据.方法 选择35例健康成年志愿者,分别采用三维光学捕捉系统Optitrack和医学交互软件Mimics获取37个面部软组织常用标志点三维坐标,标志点直接粘贴于面部皮肤（直接定点法）或标定在软组织CT三维重建模型上（间接定点法）,采用组内相关系数和配对t检验比较两种定点方法的可靠性和可重复性.结果 在直接定点法中,86.5％的标志点标定的组内相关系数＞0.75;在间接定点法中,有75.7％的标志点标定的组内相关系数＞0.75.直接定点法（1.259±0.566）mm比间接定点法（1.420±0.638）mm具有较小的标志点定位误差（P＜0.05）.结论 在面部软组织测量中,直接定点法比间接定点法具有较高的可靠性和可重复性.

Objective To compare the reproducibility and reliability of facial soft tissue landmarks using a direct and an indirect placement methods in facial three-dimensional （3D） soft tissue assessment.Methods 3D coordinates of 37 soft tissue landmarks were obtained respectively in 35 normal healthy volunteers from 3D optical capture system and Materialise＆#39;s interactive medical image control system （Mimics）.Landmarks were affixed on the cutaneous surface （direct method） and marked on the 3D reconstructed craniofacial model （indirect method）.Intra-class correlation coefficients （ICCs） and paired t-tests were used to compare the reliability and reproducibility of facial landmarks between two placement methods.Results For the direct placement method,86.5 % landmarks had an ICC higher than 0.75.For the indirect placement method,75.7% landmarks had an ICC higher than 0.75.The inter-observer variability using the direct placement method was （1.259±0.566） mm,which was significantly smaller （P〈0.05） than （1.420±0.638） mm obtained by the indirect placement method.Conclusions Compared with indirect method,direct method has higher reliability and reproducibility in evaluating facial soft tissue.