Henseler H, Khambay B, Ju X, Ayoub A, Ray A K
Medizinische Hochschule Hannover, Plastische, Hand- und Wiederherstellungschirurgie, Hannover.
Faculty of Dentistry, Pediatric Dentistry and Orthodontics, Hong Kong, Hong Kong.
Handchir Mikrochir Plast Chir. 2014 Dec;46(6):342-9. doi: 10.1055/s-0034-1395578. Epub 2015 Jan 7.
The aim of this presentation is the explanation of a mathematical analysis of a landmark-based procrustes calculation. The various components of breast symmetry and their impact on breast reconstruction have been examined.
In an objective breast shape analysis asymmetries are quantified as a measure of the difference between a 3D landmark configuration of a breast and its mirror image. 10 landmarks, 4 on each side and 2 for a definition of the midline were defined. For each landmark the 3D coordinates were calculated statistically with the help of the software Programme R. Over a midline from the jugulum to the manubrium sterni, a mirror image of the breast was constructed. The data for the breast to be reconstructed and the non-operated breast from 44 patients were investigated. The statistical differences of the Procrustes analysis were used for an asymmetry score and the proportions of the individual components were calculated. These included size, location and orientation of the breast as well as the individual inherent morphological surface form data of the breast.
All 44 patients exhibited breast asymmetries and the mean asymmetry score amounted to 0.52. A calculation of the proportions of the individual components making up the asymmetry score revealed that morphological surface data made the largest contribution to the asymmetry score, closely followed by location, i. e., positioning of the breast on the thoracic wall. In contrast, the size of the breast and its orientation were of lesser relevance.
When considering breast symmetry in plastic surgery, the form plays a more important role than the size as objectively calculated by the statistical procrustes analysis. Almost equally important as the form is the positioning of the breast on the thoracic wall which contributes significantly more to total breast symmetry than axial displacements.
本报告旨在解释基于地标点的普氏分析的数学分析方法。研究了乳房对称性的各个组成部分及其对乳房重建的影响。
在客观的乳房形状分析中，不对称性被量化为乳房的三维地标点配置与其镜像之间差异的一种度量。定义了10个地标点，每侧4个，2个用于定义中线。借助R软件程序，对每个地标点的三维坐标进行统计计算。在从胸骨柄到胸骨体的中线上构建乳房的镜像。研究了44例患者待重建乳房和未手术乳房的数据。普氏分析的统计差异用于计算不对称分数，并计算各个组成部分的比例。这些组成部分包括乳房的大小、位置和方向以及乳房的个体固有形态表面数据。
44例患者均存在乳房不对称，平均不对称分数为0.52。对构成不对称分数的各个组成部分的比例进行计算后发现，形态表面数据对不对称分数的贡献最大，其次是位置，即乳房在胸壁上的定位。相比之下，乳房的大小及其方向的相关性较小。
在整形外科中考虑乳房对称性时，根据统计普氏分析客观计算得出，形态比大小起着更重要的作用。与形态几乎同样重要的是乳房在胸壁上的定位，其对乳房整体对称性比轴向位移的贡献要大得多。
