An insight into four orthodontic treatment need indices

Occlusal indices have been introduced and used to rank or categorize the occlusion. According to Dr. William Shaw and colleagues (1995), there are five types of occlusal indices, diagnostic, epidemiologic, orthodontic treatment need, orthodontic treatment outcome, and treatment complexity indices. Orthodontic treatment need indices are used to rank the malocclusion. They were devised to minimize the subjectivity associated with the diagnosis, referral and complexity assessment of malocclusion. Some are also multifunctional and used to assess the outcome of orthodontic treatment. The overall aim of the present article is to provide an overview on four commonly used American and European orthodontic treatment need indices, review their modifications, advantages, and limitations. These indices are the Index of Orthodontic Treatment Need (IOTN), the Dental Aesthetic Index (DAI), the Handicapping Labio-Lingual Deviation index (HLD), and the Index of Complexity, Outcome and Need (ICON).