Affiliation: | aSenior Consultant, Department of Orthodontics, Postgraduate Dental Education Center, Örebro, Sweden ; bSenior Consultant, Orthodontic Clinic, Public Dental Service, Gävleborg County Council and Centre for Research and Development, Uppsala University/Gävleborg County Council, Gävle, Sweden ; cProfessor and Chair, Department of Orthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden |