Department of Orthodontics, University of Iowa, Iowa City, USA.
Am J Orthod Dentofacial Orthop. 2011 Aug;140(2):182-8. doi: 10.1016/j.ajodo.2011.04.013.
The cervical vertebrae maturation (CVM) method has been advocated as a predictor of peak mandibular growth. A careful review of the literature showed potential methodologic errors that might influence the high reported reproducibility of the CVM method, and we recently established that the reproducibility of the CVM method was poor when these potential errors were eliminated. The purpose of this study was to further investigate the reproducibility of the individual vertebral patterns. In other words, the purpose was to determine which of the individual CVM vertebral patterns could be classified reliably and which could not.
Ten practicing orthodontists, trained in the CVM method, evaluated the morphology of cervical vertebrae C2 through C4 from 30 cephalometric radiographs using questions based on the CVM method. The Fleiss kappa statistic was used to assess interobserver agreement when evaluating each cervical vertebrae morphology question for each subject. The Kendall coefficient of concordance was used to assess the level of interobserver agreement when determining a "derived CVM stage" for each subject.
Interobserver agreement was high for assessment of the lower borders of C2, C3, and C4 that were either flat or curved in the CVM method, but interobserver agreement was low for assessment of the vertebral bodies of C3 and C4 when they were either trapezoidal, rectangular horizontal, square, or rectangular vertical; this led to the overall poor reproducibility of the CVM method. These findings were reflected in the Fleiss kappa statistic. Furthermore, nearly 30% of the time, individual morphologic criteria could not be combined to generate a final CVM stage because of incompatible responses to the 5 questions. Intraobserver agreement in this study was only 62%, on average, when the inconclusive stagings were excluded as disagreements. Intraobserver agreement was worse (44%) when the inconclusive stagings were included as disagreements. For the group of subjects that could be assigned a CVM stage, the level of interobserver agreement as measured by the Kendall coefficient of concordance was only 0.45, indicating moderate agreement.
The weakness of the CVM method results, in part, from difficulty in classifying the vertebral bodies of C3 and C4 as trapezoidal, rectangular horizontal, square, or rectangular vertical. This led to the overall poor reproducibility of the CVM method and our inability to support its use as a strict clinical guideline for the timing of orthodontic treatment.
颈椎成熟度（CVM）方法已被提倡作为预测下颌骨生长高峰的指标。对文献的仔细回顾表明，可能存在影响 CVM 方法高重复性的方法学错误，我们最近发现，当消除这些潜在错误时，CVM 方法的重复性很差。本研究的目的是进一步研究单个椎体模式的可重复性。换句话说，目的是确定哪些个体 CVM 椎体模式可以可靠分类，哪些不能。
10 名接受过 CVM 方法培训的正畸医生，使用基于 CVM 方法的问题，评估了 30 张头颅侧位片上 C2 到 C4 的颈椎椎体形态。使用 Fleiss kappa 统计量评估每个受试者的每个颈椎椎体形态问题的观察者间一致性。Kendall 一致性系数用于评估每个受试者确定“衍生 CVM 阶段”时的观察者间一致性水平。
对于 CVM 方法中 C2、C3 和 C4 的下边界是平的或弯曲的评估，观察者间一致性较高，但对于 C3 和 C4 的椎体是梯形、矩形水平、正方形或矩形垂直的评估，观察者间一致性较低；这导致 CVM 方法的整体可重复性较差。这些发现反映在 Fleiss kappa 统计量中。此外，近 30%的时间，由于对 5 个问题的回答不兼容，无法将个别形态标准组合以生成最终的 CVM 阶段。在这项研究中，当排除不确定的分期作为分歧时，平均只有 62%的观察者间一致性。当包括不确定的分期作为分歧时，观察者间一致性更差（44%）。对于可以分配 CVM 阶段的受试者组，通过 Kendall 一致性系数测量的观察者间一致性水平仅为 0.45，表明中度一致。
CVM 方法的结果较弱，部分原因是难以将 C3 和 C4 的椎体分类为梯形、矩形水平、正方形或矩形垂直。这导致了 CVM 方法的整体可重复性差，我们无法支持其作为正畸治疗时机的严格临床指南使用。
