1. Department of Otorhinolaryngology, Head and Neck Surgery, Mansoura University, Mansoura, Egypt
2. Department of Otorhinolaryngology, Head and Neck Surgery, King Abdullah Medical City, Mecca, Saudi Arabia
3. Department of Otorhinolaryngology, Head and Neck Surgery, Kaferelsheikh university, Kaferelsheikh, Egypt
4. Department of Otorhinolaryngology, Head and Neck Surgery, Tanta university, Tanta, Egypt
5. Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, Zagazig University, Zagazig, Egypt