1. Department of Plastic and Maxillofacial Surgery, Uppsala University, Uppsala, Sweden
2. Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
3. Department of Surgery, Uppsala University Hospital and Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
4. Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
5. Volvat Stokkan, Trondheim, Norway
6. Department of Plastic and Reconstructive Surgery, Lund University, Malmö, Sweden
7. Department of Surgery, Skåne University Hospital Malmö, Lund University, Malmö, Sweden