1. Department of Plastic and Reconstructive Surgery, BG University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
2. Department of Oral and Maxillofacial Surgery, Head- and Neurocentrum, University Hospital Hamburg-Eppendorf, Hamburg, Germany
3. ELB – Eloxalwerk Ludwigsburg Helmut Zerrer GmbH, Ludwigsburg, Germany
4. Department of General and Trauma Surgery, BG University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany