1. Departments of Ear Nose and Throat Surgery, University of Jos and Jos University, Teaching Hospital, Jos, Plateau, Nigeria,
2. Departments of Anaesthesia, University of Jos and Jos University, Teaching Hospital, Jos, Plateau, Nigeria,
3. Department of Health Services, ENT Unit, Ministry of Defence, Abuja, Nigeria,
4. Department of Otorhinolaryngology, University College Hospital and University of Ibadan, Ibadan, Oyo, Nigeria,