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