[Oral health care in young people insured by a health insurance fund. 2. Prevalence and treatment of malocclusions in the Netherlands between 1987-1999].

In this paper data are presented about malposition of teeth in 5-, 11-, 17- and 23-year-olds in the time period between 1987-1999. Furthermore, results are shown of a longitudinal study in youngsters 11-17-years of age of whom some were and others were not treated orthodontically. Between 1987 and 1999, the percentage of youngsters who received orthodontic treatment increased from 23% to 40%. In the same time period the percentage of youngsters 17- and 23-year-olds with a malposition of teeth decreased. In youngsters involved in the longitudinal study and treated orthodontically, a strong improvement of the tooth position was found between the age of 11 and 17. Such an improvement did not appear in the non-treated group. The outcomes are considered as an indication that orthodontic treatments have positive effects on individual and on population level.