1. Division of Ear-Nose and Throat, Department of Surgery, Faculty of Clinical Science, College of Medical Sciences Ahmadu Bello University and Ahmadu Bello University Teaching Hospital, Zaria, Kaduna State, Nigeria
2. Department of Pathology and Morbid Anatomy, Faculty of Basic Clinical Sciences, College of Medical Sciences, Ahmadu Bello University and Ahmadu Bello University Teaching Hospital, Zaria, Kaduna State, Nigeria
3. Department of Otorhinolaryngology, Aminu Kano Teaching Hospital Kano, Kano, Kano State, Nigeria
4. Federal Medical Centre, Abuja, Nigeria
5. Department of Ear, Nose and Throat, Lagos State University Teaching Hospital, Ikeja, Lagos State, Nigeria