An alternative to study model storage

The aim of this investigation was to evaluate whether the same orthodontic information can be obtained from study models and photographs of study models for the purposes of medico-legal reporting. Thirty sets of study models were obtained from orthodontic patients treated at the University of Manchester, UK. A mix of start and finish study models were chosen, with the start study models showing a range of malocclusions. Photographs of the study models were taken: anterior and right and left buccal views in occlusion and upper and lower occlusal views. Three examiners assessed the study models and photographs of the models in a random order. They recorded diagnostic information that would be useful for medico-legal reporting. This information was then compared for study models versus photographs of study models using intraclass correlation coefficients (ICCs) for interval data [overjet (mm), midline discrepancy (mm), and number of missing teeth] and kappa (kappa) and percentage agreement for the remaining variables. Generally, agreement between the information obtained from study models versus photographs of study models was high with kappa values being above 0.70 for most variables. The exception to this was overbite with kappa values ranging from 0.66 to 0.74. When ICCs were considered, again the two methods compared very favourably.