Effect of training and experience on cephalometric measurement errors on surgical patients.

The aim of this study was to quantify and compare the cephalometric measurement errors (interexaminer errors) between two orthodontic residents and two oral and maxillofacial surgical residents with differing years of experience. It was hypothesized that the measurement errors would differ between observers with different training backgrounds and experience and that this would lead to significant disagreements in the cephalometric assessment of patients to receive combined orthodontic and orthognathic surgical treatment. Thirty cephalograms were used in the evaluation. Each examiner independently digitized all cephalograms twice. Common cephalometric skeletal and dental variables, 18 angular and 9 linear, were measured. Interexaminer errors were calculated using two-sample t tests for every pair of examiners. The interexaminer error was large in both landmark identification and in angular and linear measurements. The amount of error did not depend on training or experience but probably on individual conception of landmark definition and perception of landmark location. Methods to limit interexaminer measurement errors are described.