1. Department of Cranio-Maxillofacial Surgery, University Hospital Regensburg, 93042 Regensburg, Germany
2. Tumor Center, Institute for Quality Management and Health Services Research, University of Regensburg, 93053 Regensburg, Germany
3. Department of Otorhinolaryngology, University Hospital Regensburg, 93042 Regensburg, Germany
4. Department of Internal Medicine 5, Hematology/Oncology, Friedrich-Alexander University Erlangen-Nürnberg, 91054 Erlangen, Germany
5. Department of Orthodontics, University Hospital Regensburg, 93042 Regensburg, Germany
6. Department of Otorhinolaryngology, St. Elisabeth Hospital Straubing, 94315 Straubing, Germany
7. Department of Plastic and Reconstructive Surgery, University Hospital Regensburg, 93042 Regensburg, Germany