PREDICTORS OF FIXED ORTHODONTIC TREATMENT IN 15-YEAR-OLD ADOLESCENTS IN SOUTH AUSTRALIA

An understanding of the determinants of the provision of fixed orthodo ntic treatment would be beneficial in the planning of any system aimed at rationalising supply. The aim of this longitudinal study was to de termine 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 intercepti ve orthodontic care, a dental appearance score (DAI), socio-demographi c characteristics and self and parental perceptions of both dental app earance and need for fixed orthodontic treatment were obtained from 27 93 adolescents under the care of the South Australian School Dental Se rvice who had not undergone fixed orthodontic treatment. Data on the o rthodontic care provided to these adolescents in the ensuing 2 years w ere collected. At the end of the 24-month period 433 adolescents (15.5 %) had undergone fixed orthodontic treatment. Significant bivariate as sociations were found between the provison of fixed orthodontic treatm ent and the DAI score, sex of the adolescent, familial history of fixe d orthodontic treatment, income, private insurance, orthodontic consul tation and interceptive orthodontic care before the age of 13 years an d self and parental perceptions of both dental appearance and the need for fixed orthodontic treatment. Logistic regression was used to prod uce a predictive model of fixed orthodontic treatment. The model expla ined 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 fou nd for the DAI score, private insurance, females, self and parental pe rception of need, higher incomes and orthodontic consultation and inte rceptive orthodontic care before the age of 13 years.