1. Department of Orthodontics, University Denial Hospital of Manchester, Manchester, United Kingdom
2. Department of Orthodontics, Karolinska Institute, Stockholm, Sweden
3. Department of Orthodontics, Royal Dental College, Copenhagen, and Head, Dental Service, Institution for Speech Disorders, Hellerup, Denmark
4. Department of Orthodontics, Royal Dental College, Copenhagen, Denmark
5. Hospital for Sick Children, London, England
6. Vrije University, Amsterdam, The Netherlands
7. Department of Plastic Surgery, University Hospital of Oslo, Norway
8. Division of Dentistry, Childrens Hospital, Los Angeles, California
9. Department of Orthodontics, Vrije University, Amsterdam, The Netherlands.