Validation and component assessment of orthodontic treatment need, complexity and outcome indices

Abstract

Introduction: One of the major challenges in orthodontics is the availability of a suitable objective method for recording the severity and complexity of an orthodontic problem. As a result, occlusal indices were realized initially as a tool to classify or rank occlusion. A great number of occlusal indices appeared since the 50’s and 60’s to minimize the subjectivity related to the diagnosis, severity, complexity and treatment outcome of malocclusions. Despite the great number of occlusal indices, there have been many disagreements among authors, with no universally accepted index for measuring malocclusion. Objective: The aims of this study were to -1- evaluate and validate the most commonly used indices: Index of Orthodontic Treatment Need (IOTN) that includes a dental health component (DHC) and an aesthetic component (AC), Peer Assessment Rating Index (PAR), Index of Complexity, Outcome, and Need (ICON), Discrepancy Index (DI) as well as a recently published Facial Aesthetic Index (FAI); -2- introduce modifications encompassing teeth, cephalometrics and facial esthetics; -3- compare the indices with each other. Each index was assessed as a measure of orthodontic treatment need, complexity, and outcome. Thus, not restricted to the respective original objective for which it was developed. Methods: This validation study included the pre- and post-treatment lateral cephalometric and panoramic x-rays, dental casts, and photographs of 101 participants. Data were collected from the files and records of patients treated at the Division of Orthodontics and Dentofacial Orthopedics at the American University of Beirut Medical Center AUBMC. The participants were randomly selected, from a list containing all patients whose orthodontic treatment was completed and appliances removed by the orthodontic residents of the same class (2015). The indices were validated against the independent judgments of a panel of four experienced orthodontists ‘gold standard’ who met strict criteria for inclusion. Pr