1. Faculty of Medicine, University of Geneva, Geneva, Switzerland
2. Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospitals, Geneva, Switzerland
3. Department of Plastic Surgery and Hand Surgery, University Hospital Basle, Basle, Switzerland
4. Institute of Medical Statistics and Epidemiology, Klinikum rechts der Isar, Technische Universtät München, Munich, Germany
5. Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital Basle, Basle, Switzerland