1. Department of Orthodontics and Dentofacial Orthopaedics University of Heidelberg Heidelberg Germany
2. Department of Otorhinolaryngology, Head and Neck Surgery University of Heidelberg Heidelberg Germany
3. ENT practice Prof. Sertel Ludwigshafen am Rhein Germany
4. Department of Prosthodontics University of Würzburg Würzburg Germany