1. ENT Service Kinshasa University Hospital Kinshasa Democratic Republic of Congo
2. Ophtalmology Service Kinshasa University Hospital Kinshasa Democratic Republic of Congo
3. Department of Otorhinolaryngology and Head and Nose Surgery University Hospital of Leuven Leuven Belgium
4. Department of Otorhinolaryngology, Academic Medical Center University of Amsterdam Amsterdam The Netherlands
5. Upper Airways Research Laboratory University of Ghent Ghent Belgium