van Spronsen P H, Koolstra J H, van Ginkel F C, Weijs W A, Valk J, Prahl-Andersen B
Department of Orthodontics, Academic Center for Dentistry Amsterdam (ACTA), The Netherlands.
Eur J Orthod. 1997 Jun;19(3):313-28. doi: 10.1093/ejo/19.3.313.
It has been suggested that subjects with increased vertical craniofacial dimensions have relatively oblique orientated jaw muscles with a reduced possibility to restrain the vertical component of craniofacial growth. To test this hypothesis, relationships were investigated between the spatial orientation of the jaw muscles and the craniofacial morphology. Computer reconstructions of the external shape of the jaw muscles of 30 adult males with a normal skull were made with the use of serial magnetic resonance imaging (MRI) scans. The orientation of the jaw muscles was defined by a regression line through the centroids of the serial cross-sections. Sagittal and frontal projections of the moment arms of the muscles were measured with respect to the centre of the ipsilateral condyle. Craniofacial morphology was analysed three-dimensionally using lateral head films and coronal MRI scans. The cephalometric data were analysed statistically using regression and factor analyses. Six cephalometric factors with Eigen values higher than 1 were correlated with jaw muscle orientation and moment arm data, using a multiple regression analysis. The anterior face height factor was significantly correlated with the orientation of the jaw opening muscles in the sagittal plane but was not significantly correlated with the orientation of the mandibular elevators. The sagittal moment arms of the mandibular elevators showed significant correlations with the factors describing the gonial angle and the posterior face height. It was concluded that the variation of spatial orientation of the human jaw closing muscles is predominantly associated with the variation of mandibular morphology (expressed by the gonial angle) and the posterior face height. The orientation of the jaw opening muscles shows significant relationships with anterior vertical craniofacial dimensions. The hypothesis that persons with an increased anterior face height have relatively oblique orientated jaw elevators was rejected.
有人提出，垂直颅面尺寸增加的受试者其颌骨肌肉的方向相对倾斜，抑制颅面生长垂直分量的可能性降低。为了验证这一假设，研究了颌骨肌肉的空间方向与颅面形态之间的关系。利用系列磁共振成像（MRI）扫描对30名颅骨正常的成年男性颌骨肌肉的外部形状进行了计算机重建。颌骨肌肉的方向由穿过系列横截面质心的回归线定义。相对于同侧髁突中心测量肌肉力臂的矢状面和额状面投影。使用侧位头颅片和冠状面MRI扫描对颅面形态进行三维分析。使用回归分析和因子分析对头颅测量数据进行统计学分析。使用多元回归分析，将特征值高于1的六个头颅测量因子与颌骨肌肉方向和力臂数据相关联。前面部高度因子与矢状面颌骨开口肌肉的方向显著相关，但与下颌升肌的方向无显著相关性。下颌升肌的矢状力臂与描述下颌角和后面部高度的因子显示出显著相关性。得出的结论是，人类颌骨闭合肌肉空间方向的变化主要与下颌形态的变化（以下颌角表示）和后面部高度有关。颌骨开口肌肉的方向与前垂直颅面尺寸显示出显著关系。前面部高度增加的人其颌骨升肌方向相对倾斜这一假设被否定。
