The value of the aesthetic component of the Index of Orthodontic Treatment Need in the assessment of subjective orthodontic treatment need

Previous studies carried out using the Index of Orthodontic Treatment Need (IOTN) have reported that the Aesthetic Component (AC) has limited use in schoolchildren. The purpose of this study was to estimate whether dental concern expressed by the grade of the AC chosen by subjects is reliable and whether it may be predictive for potential co-operation. Such a correlation would indicate if the AC of the IOTN may help to identify individuals interested in orthodontic treatment who would co-operate well, and consequently who might derive the greatest benefits. The investigation was carried out in north-west Poland among 84 schoolchildren (42 girls and 42 boys) aged 12 years and was based on a questionnaire and clinical examination. The questionnaire contained items relating to the subjective assessment of dental appearance, demand for orthodontic treatment, the influence of the dentition on the general appearance, and any functional disorders (speech, mastication, muscular pain, etc.). Clinical examination was carried out at the schools each time by the same dentist. For statistical analysis chi-square (Yates corrected) and McNemar tests were used. A probability at the 5 per cent level or less (P less than or equal to 0.05) was considered statistically significant. The outcome shows that the AC of the IOTN moderately reflects the subjective perception of dental aesthetics and demand for orthodontic treatment. The results indicate that using professional rating the AC scale does not seem to be more precise or reliable than self-evaluation. The correlation between dental concern and the AC would be higher if the 'no treatment need' category was split into two parts (e.g. 1-2 'no need', 3-4 'slight need') or the 'borderline need' category was moved two grades lower. The AC would then help to identify patients interested in treatment who would potentially be co-operative.