Methods: 6 orthodontists were asked to score pre-treatment diagnostic records of 100 patients in this study. The samples represented a uniform distribution of different types of malocclusions determined by DHC component of the IOTN index. A calibrated examiner also assessed the need and complexity of the cases based on the ICON index. 10 days later, 25% of the cases were re-scored by the panel of experts as well as the calibrated examiner.
Results: The Weighted Kappa revealed the inter-examiner reliability of the experts to be 0.63 and 0.51 for the need and complexity components, respectively. ROC curve was used to assess the validity of the ICON at the suggested international cut-off point which is set at 43. A new cut-off point was adjusted at 35.5.which shows the highest level of sensitivity and specificity for our community(0.77 and 0.78, respectively). But it failed to define definite ranges for the complexity of treatment based on the opinion of the panel of experts.
Conclusions: ICON in a valid index in assessing the need for treatment when the cut-off point is adjusted to 35.5. As for complexity of treatment, the index is not validated for our society.