A retrospective cephalometric study of Class I patients.
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.