Orthodontic treatment practices in Finnish municipal health centres with differing timing of treatment

The aim of this study was to compare orthodontic practices in eight Finnish municipal health centres selected on the basis of an earlier survey to represent early and late timing of treatment. The health centres were grouped according to the mean age of starting treatment; earlier versus later than 9 years of age. A random sample of 16 and 18 year olds (n = 2325) living in these municipalities were invited for a clinical examination, and 1109 adolescents participated. The participants reported on their previous or ongoing orthodontic treatment by means of a questionnaire. Data on orthodontic treatment received were collected from the dental files of the adolescents who reported a treatment history and for those who did not recall exactly whether or not they had received orthodontic treatment. Analysis of the non-respondents was made on the basis of their dental files. Differences between the features of orthodontic treatment in the early and late starting health centres were analysed using a two-tailed t-test. In the early group, 70 per cent, and in the late group 42 per cent, of adolescents had a history of orthodontic treatment. General dentists carried out 90 per cent of the treatment in the early group and specialists every third treatment in the late group. An early start resulted in more frequent visits (P = 0.004) and a longer treatment duration (P < 0.001), while later timing resulted in an increase in the number of appliances (P < 0.001).