Effectiveness of training dental students in two occlusal indices.

The purpose of this study was to evaluate the ability of students in a U.S. dental school to learn and apply two indices of orthodontic need: the Index of Orthodontic Treatment Need (IOTN) and the Index of Complexity, Outcome, and Need (ICON). Dental students were randomly selected and separated into three groups: control, IOTN, and ICON. Each evaluated thirty casts that had previously been evaluated by a panel of thirteen orthodontists to develop a gold standard of orthodontic treatment need for these casts. Students re-evaluated the same thirty casts after IOTN and ICON training for their own group, while the control group did not receive any training. Logistic regression of pre- and post-training agreement with the gold standard was calculated for each group to create a clear quadratic relationship. Significant differences were not found between pre- and post-training evaluation for either the IOTN or the ICON groups as compared to the control. However, the IOTN group did show more improvement when compared with the ICON group. This study demonstrates that the use of the IOTN index improved assessment in predoctoral dental students to determine orthodontic treatment need.