The use of orthodontic need index (IOTN) in a referred Iranian population

Background: IOTN index has been used in different countries for assessment of orthodontic treatment needs in recent years. This index has two components, an aesthetic component (AC) and a dental health component (DHC). Objective: The aim of this study was assessment of orthodontic needs on the basis of IOTN index in those people who had come for orthodontic treatment. Methods: We used IOTN index in order to assess the orthodontic treatment needs of 343 applicants (262 females and 81 males) with a mean age of 18.1(standard deviation 3.8 years). Who had come for treatment during a certain period of time(8 months) For determining the AC we used a set of 10 pictures graded on the basis of aesthetical features of teeth. The DHC Component of Index that has five degrees was determined bases on study casts with standard preparation. If necessary and for more accuracy panoramic radiographies of patients were also used. The analysis of the obtained data was performed using Kappa, Chi-square and Spearman’s tests. Findings: The results with determination of subjective needs on the basis of AC by patient’s perceived need indicate a lock of significant relation between gender and the patients’ perceived need for AC( p0.05). Conclusion: Subjective data of IOTN index alone can not be considered an appropriate indicator of orthodontic treatment needs determination.