1. Department of Otorhinolaryngology, University of Regensburg, Regensburg, Germany
2. Department of Otorhinolaryngology, University of Zurich, Zurich, Switzerland
3. Department of Prosthetic Dentistry, University of Regensburg, Regensburg, Germany
4. Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany