1. Department of Orthodontics Academic Center for Dentistry, Amsterdam, the Netherlands, University Medical Center, Amsterdam, the Netherlands.
2. Department of Orthodontics, Academic Center for Dentistry, Amsterdam, the Netherlands, Department of Orthodontics, Dijkzigt University Hospital, Rotterdam, the Netherlands.
3. Department of Preventive and Curative Dentistry, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands.
4. Department of Orthodontics and Oral Biology and Cleft Palate Craniofacial Unit of the Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands