1. CRANE Database, Clinical Effectiveness Unit, Royal College of Surgeons of England, London, United Kingdom.
2. CRANE Database, Clinical Effectiveness Unit, Royal College of Surgeons of England, and Health Services Research and Policy, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom.
3. Consultant Paediatric Ear, Nose, and Throat Surgeon, Department of Ear, Nose and Throat, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom.
4. South West Cleft Unit, Bristol Dental Hospital, Bristol, United Kingdom