1. Division of Orthodontics and Pediatric Dentistry, Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden;
2. Department of Pediatric Dentistry, Eastman Institute, Public Dental Service, Stockholm, Sweden;
3. Center of Pediatric Oral Health, Stockholm, Sweden;
4. Division of Health Care Analysis, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden