1. Clinic for Otorhinolaryngology and Maxillofacial Surgery, Clinical Center of Serbia, Belgrade, Serbia
2. Medical Faculty, University of Belgrade, Belgrade, Serbia
3. Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
4. Ear, Nose and Throat Clinic, Clinical Hospital Center Zvezdara, Belgrade, Serbia
5. ENT Hospital, Clinical Hospital Center ‘‘Dr Dragisa Misovic-Dedinje’‘ Belgrade, Serbia
6. Institute of Pathology, Medical Faculty, University of Belgrade, Belgrade, Serbia