1. Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, Medical Centre, University of Freiburg, 79106 Freiburg, Germany
2. Department of Otorhinolaryngology, Head and Neck Surgery, Klinikum rechts der Isar, Technical University, 81675 Munich, Germany
3. Clinic and Policlinic for Oro-Maxillofacial Surgery, Klinikum rechts der Isar, Technical University, 81675 Munich, Germany
4. Department of Oral and Maxillofacial Surgery, Josefinum, Augsburg and Private Practice Oral and Maxillofacial Surgery im Pferseepark, 86157 Augsburg, Germany