Variability in assessment of need for orthodontic treatment when using certain treatment-need indices

The need for orthodontic treatment was assessed in a sample of 29 children by using four treatment-need indices (ISMHB by the Swedish Medical Health Board, HMAR by Salzmann, INOT by Ingervall & Rönnerman, and TPI by Grainger). Furthermore, the need for treatment was evaluated clinically according to the criteria of Järvinen. When scoring the cases, and when selecting the cases with the highest scores, the study showed a marked variation between the indices, and indicated that the different methods selected different groups of children for treatment. Indirectly, the conclusion could be drawn that there were differences in the validity of the indices, even though it was not possible to evaluate the degree of validity on the basis of the knowledge we have today about the disadvantages and consequences of malocclusions.