1. Department of Otolaryngology and Head and Neck Surgery, Rush University Medical Center, Chicago
2. Department of Otolaryngology, Advanced Center for Specialty Care, Advocate, Illinois Masonic Medical Center, Chicago
3. Department of Otolaryngology, Kasimpasa Military Hospital, Istanbul
4. Department of Otolaryngology, Chang Gung Memorial Hospital - Kaohsiung Medical Center, Chang Gung University College of Medicine, Turkey; and Kaohsiung, Taiwan