Background: Different indices have been used to determine orthodontic treatment needs such as the Dental Aesthetic Index (DAI) and the index of orthodontic treatment needs (IOTN).
Objectives: The present study was carried on to compare the dental aesthetic index (DAI) and the IOTN’s dental health component (DHC) in assessment of orthodontic treatment needs of 11 - 14 year old schoolchildren in Qazvin.
Methods: In a cross-sectional descriptive study, 250 of 11 - 14 year old schoolchildren from two school districts of Qazvin were selected by a two-stage stratified cluster sampling method and their AC scores were determined according to the orthodontist and child’s own idea. Also the subjects’ DHC and DAI scores were determined according to the existing standards. The patients’ demographic data were recorded by means of a questionnaire and correlations between AC’s as determined by the subject and by the orthodontist, as well as scores of the DHC and the DAI, were analyzed using Spearman correlation ratio.
Results: The mean of AC score as determined by the subject was 2.556, while the scores by the orthodontist were 4.308; while DHC score was 2.60 and DAI score was 26.86. The coefficient of correlation between students and specialist AC, students AC and DAI, specialist AC and DHC, specialist AC and the DAI,DHC and the DAI, students AC and DHC was respectively 0.269, 0.262, 0.549, 0.506,0.794(In all cases P < 0.0001) and 0.202 (P < 0.001).
Conclusions: Existence of a positive and significant relationship between the AC, the DHC and the DAI indicates their potential for determining the need for orthodontic treatment. The highest need for orthodontic treatment was determined by the AC of the specialist and the lowest need by that of the patient. Only gender of the student had a significant effect on the values of the DHC and the DAI as determined by the specialist.