Legrell P E, Nyquist H, Isberg A
Department of Oral and Maxillofacial Radiology, Umeå University, Sweden.
Angle Orthod. 2000 Apr;70(2):157-64. doi: 10.1043/0003-3219(2000)070<0157:VOIOGA>2.0.CO;2.
This study was designed to develop a method of transferring gonion from lateral to frontal cephalograms, and to use this method as gold standard when evaluating observer performance in identifying gonion in frontal cephalograms. Observer ability to identify antegonion was also evaluated. There was a range of 28 mm in the observers' identification of gonion and a statistically significant deviation from gold standard. The factors "observer" and "cephalogram," regarded as random effects in an ANOVA analysis, and their interaction, each influenced the result, P < .001. The deviation from the mean of all observations for antegonion ranged 8 mm with "cephalogram" having a statistically significant influence. The results suggest that neither gonion nor antegonion can be routinely used as valid landmarks in frontal cephalograms. Gonion can, however, be used if first identified in a lateral cephalogram and transferred to a paired frontal cephalogram aided by radiographic indicators combined with a bilateral scrutiny of projection geometry in different planes through gonion and indicator.
本研究旨在开发一种将下颌角从侧位头影测量片转移至正位头影测量片的方法，并在评估观察者识别正位头影测量片中下颌角的表现时，将该方法用作金标准。同时也评估了观察者识别下颌前点的能力。观察者对下颌角的识别存在28毫米的差异范围，且与金标准存在统计学上的显著偏差。在方差分析中被视为随机效应的“观察者”和“头影测量片”因素及其交互作用，均对结果产生影响，P <.001。下颌前点与所有观察均值的偏差范围为8毫米，“头影测量片”具有统计学上的显著影响。结果表明，在下颌正位片中，下颌角和下颌前点均不能常规用作有效的标志点。然而，如果首先在侧位头影测量片中识别出下颌角，并借助射线照相指标以及通过下颌角和指标在不同平面进行的双侧投影几何结构仔细检查，将其转移到配对的正位头影测量片上，则下颌角可以使用。
