Evaluation of the reproducibility of clinical decision by cervical vertebral maturation staging

Abstract

Time plays a crucial role in determining the final morphology and dimensions of a growing somatic structure. In orthodontics, timing of treatment could be as important as treatment plan. Cervical vertebrae morphology varies with growth. Since, the cervical vertebrae are visible in the lateral cephalograms which orthodontists typically use and does not need extra exposure to x-ray, assessment of skeletal age from cervical vertebrae maturation (CVM method), is a reliable method. Whit considering that the aim of using the CVMS method is to determine the best time to start the growth modification treatment so it is more logical and practical to evaluate the reproducibility of clinical decision by CVMS than evaluation of reproducibility of each stage. moreover; as the method of CVMS is based on the shape and the curvature of the lower border of the vertebrae, the poor or high reproducibility of this method is related to reproducibility of determining each of these items. So, in this study we are going to investigate the reproducibility of clinical decision by CVMS and search about the reason of the poor reproducibility of this method by evaluation of reproducibility of each item. Materials & Methods: Seventy pretreatment lateral cephalograms of Iranian patients between 7 and 15 years of good-quality with complete visualization of four cervical vertebrae, were observed by five experienced orthodontists according to method of Baccetti et al and the observers were asked to determine the shape (trapezoidal, rectangular horizontal, square or rectangular vertical) and curvature of the lower border (flat or curved). Inter-observer reproducibility was calculated using weighted Kohen's kappa and intra-observer reproducibility was calculated using Fleiss kappa test. Results: The inter-observer reproducibility of clinical decision by CVMS was between 0.61- 0.77 which according to Landis and Koch??s classification is substantial. The reproducibility intra-observer was in range of 0.92-0.57 (mean: 0.74). The reproducibility inter-observer of the shape of C3 was between 0.44-0.51(mean: 0.49) and for C4 was between 0.48-0.56 (mean: 0.52) which both were moderate. The reproducibility inter-observer of the curvature of the lower border of C2 was between 0.61-0.68 (mean: 0.67) and for C3 was between 0.76-0.79(mean: 0.73) and for C4 0.74-0.66 (mean: 0.71) which all were substantial. The intra-observer reproducibility of the shape of C3 was between 0.64-0.77 (mean0.70 0.06) for the fourth vertebrae between 0.61-0.77 (mean: 0.70 0.07). Reproducibility intra-observer of the border of the second vertebra was between 0.65-0.85 (mean: 0.14 0.71) and for the border of the third vertebrae was between 0.64-0.97 (mean: 0.86 0.14) and for fourth vertebrae was between 0.94-0.72 (mean: 0.84 0.10). Conclusions: CVMS has an acceptable reproducibility in determining timing of functional treatment for Class II patients. The poor repeatability of CVMS method is related to poor reproducibility of determine the shape of vertebrae C3 and C4