The purposes of this study were to establish the reproducibility of skeletal age assessment as determined by the stage of cervical vertebral maturation (CVM) and to assess the ability of the CVM method to predict timing of peak mandibular growth velocity (PMdGV). The longitudinal records of 104 females (age 8 to 14 inclusive) were used to determine skeletal age (as assessed by the CVM) and mandibular length. Reproducibility of skeletal age estimates was tested by comparing five sets of first and second determinations done 2 months apart for 20 subjects chosen from the total sample before and after the principal operator calibration. The reproducibility of skeletal age assessments done prior to calibration was unacceptable. The reproducibility improved to acceptable limits following calibration. Improved definitions, the addition of an extra stage and the development of a Sequential Conditional Flow Chart rendered the modified CVM method, introduced in this study, even more reproducible. The kappa for 20 double assessments of the timing of PMdGV was 59% (not acceptable) but of the 55 subjects for whom two determinations of timing of PMdGV coincided, only 61% were at cervical vertebral stage 3 thus lending some measure of uncertainty to the use of the cervical vertebral maturation method for predicting timing of PMdGV
