Predictors of fixed orthodontic treatment in 15-year-old adolescents in South Australia

Abstract An understanding of the determinants of the provision of fixed orthodontic treatment would be beneficial in the planning of any system aimed at rationalising supply. The aim of this longitudinal study was to determine those factors which were predictive of the provision of fixed orthodontic treatment in adolescents. Baseline data, at age 13 years, on oral health, the history of orthodontic consultation and interceptive orthodontic care, a dental appearance score (DAI), socio-demographic characteristics and self and parental perceptions of both dental appearance and need for fixed orthodontic treatment were obtained from 2793 adolescents under the care of the South Australian School Dental Service who had not undergone fixed orthodontic treatment. Data on the orthodontic care provided to these adolescents in the ensuing 2 years were collected. At the end of the 24-month period 433 adolescents (15.5%) had undergone fixed orthodontic treatment. Significant bivariate associations were found between the provison of fixed orthodontic treatment and the DAI score, sex of the adolescent, familial history of fixed orthodontic treatment, income, private insurance, orthodontic consultation and interceptive orthodontic care before the age of 13 years and self and parental perceptions of both dental appearance and the need for fixed orthodontic treatment. Logistic regression was used to produce a predictive model of fixed orthodontic treatment. The model explained 30.2% of the variance, with a specificity of 0.94, a sensitivity of 0.49 and a hit rate of 0.84%. Odds ratios greater than one were found for the DAI score, private insurance, females, self and parental perception of need, higher incomes and orthodontic consultation and interceptive orthodontic care before the age of 13 years.