Computational formulation of orthodontic tooth-extraction decisions

Abstract

Objective: To develop a mathematical model that simulates whether or not to extract teeth inoptimizing orthodontic treatment outcome and to formulate the morphologic traits sensitive tooptimizing the tooth-extraction/nonextraction decisions.Materials and Methods: A total of 188 conventional orthodontic records of patients with goodtreatment outcomes were collected, and dentofacial morphologic traits, along with their degreesof influence in the optimized model, were determined.Results: The rate of coincidence between the recommendations given by the optimized modeland the actual treatments performed was found to be 90.4%. The major morphologic traits andtheir corresponding influences in improving the simulation accuracy of the model were the incisoroverjet (3.0) and the size of the basal arch relative to the sum of the mesiodistal crown diametersof the upper dentition (2.4) and the lower dentition (2.0). The remaining 22 morphologic-traitvariables were also found to be indispensable in achieving robust simulation readings.Conclusion: A mathematical model that simulates whether or not to extract teeth in optimizingorthodontic treatment outcomes with a success rate of 90.4% at its prediction performance wasdeveloped. This model has 25 morphologic traits with four major categories (sagittal dentoskeletaland soft tissue relationship, vertical dentoskeletal relationship, transverse dental relationship, andintra-arch conditions) that affected the accuracy in determining optimal tooth extractions/nonextractions. (Angle Orthod. 2009;79:885-891. © 2009 by The EH Angle Education and Research Foundation, Inc.