Validity of two occlusal indices for determining orthodontic treatment needs of patients treated in a public university in Belo Horizonte, Minas Gerais State, Brazil

The aim of the present study was to validate the dental aesthetic index (DAI) and index of complexity, outcome and need (ICON) based on the opinions of a panel of Brazilian orthodontists. A comparison of these two orthodontic treatment need indices was carried out based on the consensus of a panel of 20 experienced orthodontists. A set of 108 study casts representing the full spectrum of malocclusions was selected. A calibrated examiner scored the casts for both indices. The orthodontists individually rated the casts regarding the degree of orthodontic treatment need. The panel's mean rating of the need for treatment was used as the gold standard for evaluating the validity of the indices. The accuracy of the indices, as reflected in the area under receiver-operating characteristic curves, was high: DAI = 81.83% (95% CI: 71.21-92.44); ICON = 88.75% (95% CI: 78.57-98.92). Although the accuracy of the ICON was higher than that of the DAI, both indices are recommended for determining orthodontic treatment need in Brazil.