Orthodontic treatment need in Spanish schoolchildren: an epidemiological study using the Index of Orthodontic Treatment Need

The aim of this study was to determine the prevalence of malocclusion and orthodontic treatment need in 12- to 16-year-old Spanish schoolchildren using the aesthetic component (AC) and Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN) and to analyse the relationship with gender and age. The study followed the World Health Organization recommendations for oral health surveys. The sample comprised 655 schoolchildren (306 males and 349 females) who had not undergone orthodontic treatment, divided into two groups: 363 12-year-olds and 292 15- to 16-year-olds, out of a representative sample of the school population of the Valencian Community. The IOTN results were analysed with regard to gender using the chi-square test. Orthodontic treatment need, using the DHC, was found in 21.8 per cent of the 12-year-olds and in 17.1 per cent of the 15- to 16-year-olds; and with the AC in 4.4 and 2.4 per cent, respectively. Considering both components together, 23.5 per cent of the population [confidence interval (CI) 95%: 19.2-28.1] of 12-year-olds and 18.5 per cent (CI 95% 14.2-23.4) of 15- to 16-year-olds had a definite treatment need. No gender dependent differences were found. Spanish orthodontic treatment need is similar to that reported in most recent studies in Europe, with approximately one in five to six children with an orthodontic treatment need.