Lavelle C
Department of Oral Biology, Faculty of Dentistry, University of Manitoba, Winnipeg, Canada.
Br J Orthod. 1989 Feb;16(1):17-23. doi: 10.1179/bjo.16.1.17.
In view of the growing consensus that traditional cephalometric analyses yield data of dubious scientific validity, this study was undertaken using an alternative technique, termed finite element analysis (FEA). The study was based on 14 triangular finite elements spanning seven datum (nodal) points delineating cephalometric form. These points were delineated on lateral cephalographs taken immediately before and following the completion of orthodontic treatment for two samples of boys aged 12-16 years. Although both samples exhibited Class I molar occlusions with anterior over-crowding, one sample required bilateral maxillary and mandibular first premolar extraction prior to orthodontic treatment, while the other sample did not. FEA revealed greater cephalometric size and shape changes in the 'non-extraction' than 'extraction' samples. Such sample contrasts, however, varied depending upon the finite element included in the analysis. Further studies are therefore required to delineate the specific finite element configurations to provide precise descriptions of cephalometric change.
鉴于越来越多的人认为传统的头影测量分析得出的数据在科学有效性方面存在疑问，本研究采用了一种名为有限元分析（FEA）的替代技术。该研究基于14个三角形有限元，这些有限元跨越7个描绘头影测量形态的基准（节点）点。这些点是在对两组12 - 16岁男孩进行正畸治疗前后立即拍摄的头颅侧位片上描绘出来的。虽然两组样本均表现为I类磨牙咬合且伴有前牙拥挤，但其中一组样本在正畸治疗前需要拔除双侧上颌和下颌第一前磨牙，而另一组则不需要。有限元分析显示，“不拔牙”样本的头影测量大小和形状变化比“拔牙”样本更大。然而，这种样本对比因分析中所包含的有限元不同而有所差异。因此，需要进一步的研究来确定具体的有限元构型，以便对头影测量变化进行精确描述。
