1. Department of Ophthalmology, University Hospital Wuerzburg, Wuerzburg, Germany
2. Anatomical Institute, Semmelweis University, Budapest, Hungary
3. Department of Otorhinolaryngology, University Hospital Regensburg, Regensburg, Germany
4. ENT Department, Helios Hanseklinikum Stralsund, Stralsund, Germany
5. ENT Clinic Karlsruhe, Karlsruhe, Germany
6. Department of Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany.