Hajeer Mohammad Y, Mao Zhili, Millett Declan T, Ayoub Ashraf F, Siebert Jan Paul
University of Al-Baath Dental School, Syria.
Cleft Palate Craniofac J. 2005 Mar;42(2):113-20. doi: 10.1597/03-132.1.
To validate a new method of facial volumetric assessment that is dependent on the use of stereophotogrammetric models and a software-based Facial Analysis Tool.
The method was validated in vitro with three-dimensional (3D) models of a lifelike plastic female dummy head and in vivo with a male-subject head.
Thirty facial silicone explants were added in the nasal and perioral regions of each head, and their volumes were obtained by three different algorithms. These were compared with the actual values obtained by a "water displacement" method.
The least mean error was found with the "tetrahedron formation" method followed by the "projection" method and the "back-plane construction" method. The error with the tetrahedron formation method was 0.071 cm(3) (95% confidence interval [CI]: -0.074 to 0.2161 cm3) with the in vitro models and 0.314 cm3 (95% CI: -0.080 to 0.708 cm3) with the in vivo models. The increased volumetric assessment error observed in vivo was attributed to the registration procedure and possible changes in facial expression.
These results encourage the use of this method in the 3D assessment of orthognathic surgical outcome, provided a standardized facial expression is used for image acquisition.
验证一种依赖立体摄影测量模型和基于软件的面部分析工具的面部容积评估新方法。
该方法在体外使用逼真的塑料女性假人头三维（3D）模型进行验证，在体内使用男性受试者头部进行验证。
在每个头部的鼻区和口周区域添加30个面部硅胶植入物，并通过三种不同算法获取其体积。将这些结果与通过“排水法”获得的实际值进行比较。
“四面体形成”法的平均误差最小，其次是“投影”法和“后平面构建”法。体外模型中四面体形成法的误差为0.071 cm³（95%置信区间[CI]：-0.074至0.2161 cm³），体内模型中为0.314 cm³（95%CI：-0.080至0.708 cm³）。体内观察到的容积评估误差增加归因于配准过程和面部表情的可能变化。
这些结果鼓励在正颌手术结果的三维评估中使用该方法，前提是在图像采集时使用标准化的面部表情。
