1. Department of Orthodontics, Public Dental Health Service, Eskilstuna, Sweden
2. Postgraduate Dental Education Center, Department of Orthodontics, SE-701 11 Örebro, Sweden
3. School of Medical Sciences, Örebro University, SE-701 82, Sweden
4. University Health Care Research Center, Örebro University, SE-701 82, Sweden
5. The Institute for Postgraduate Dental Education, Department of Orthodontics, SE-551 11 Jönköping, Sweden
6. Centre for Oral Health, School of Health and Welfare, Jönköping University, Sweden