1. Department of Diagnostic and Interventional Radiology, University Hospital of Frankfurt
2. Department of Oral and Maxillofacial Surgery, University Medicine Mainz
3. Department of Otolaryngology, University Hospital of Cologne
4. Department of Otolaryngology, Hospitals of Cologne
5. Department of Otolaryngology, University Hospital of Jena
6. Department of Oral, Maxillar and Plastic Surgery, University Hospital of Düsseldorf
7. Department of Oral, Maxillofacial and Plastic Surgery, University Hospital of Bonn
8. Department of Otolaryngology, University Hospital of Schleswig-Holstein, Campus Lübeck
9. Clinic for Otolarnygology, University Hospital of Gießen/Marburg, Gießen
10. Otolaryngology, Center for Otolaryngology Regensburg
11. Clinic for Otolaryngology, Hospital of Augsburg