Orthodontic treatment need in 10-year-old Dunedin schoolchildren.

The prevalence of unmet orthodontic treatment need was assessed in a random sample of 294 10-year-old Dunedin schoolchildren using the Index of Orthodontic Treatment Need. Approximately one-third of the children from this mainly mixed-dentition sample were assessed as having a need for orthodontic treatment. No children needed orthodontic treatment on the basis of the Aesthetic Component alone, but slightly more than a quarter did on the basis of the Dental Health Component alone. The Dental Health Component was reliable and easy to use, and it assigned approximately the same number of children to the "Need", "Borderline", and "No/little" orthodontic treatment need categories. As the Aesthetic Component alone failed to identify any children needing orthodontic treatment, it may be unsuitable for use as a screening tool for orthodontic treatment need in the mixed dentition.