1. Division of Child Dental Health, University of Bristol Dental School, Bristol, England
2. Unit of Orthodontics, University Dental Hospital of Manchester, Manchester, England
3. Chelsea & Westminster Hospital, London, England
4. Department of Speech and Language Therapy at the Great Ormond Street Hospital for Children and Institute of Child Health, University of London, London, England
5. Department of Child Dental Health, The Dental School, Newcastle upon Tyne, England