1. Department of Surgery, Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria
2. Department of Anaesthesia, Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria
3. Department of ENT, Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria
4. Joe Alufohai Medical Centre, Sabongida-Ora, Edo State, Nigeria
5. Department of Surgery, Ambrose Alli University, Ekpoma, Edo State, Nigeria