1. Division of Otorhinolaryngology, Department of Surgery, Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong China
2. Division of Head and Neck Surgery, Department of Surgery, Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong China
3. Department of ENT Queen Mary Hospital Hong Kong China
4. Division of Head and Neck Surgery, Department of Otolaryngology Stanford University Palo Alto California USA
5. Hong Kong Sanatorium and Hospital, Happy Valley Hong Kong China