1. Head and Neck Cancer Research Team, Cancer Research Malaysia, Subang Jaya, Malaysia
2. Department of Oral & Maxillofacial Clinical Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia
3. Department of Otorhinolaryngology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
4. Cancer Unit, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
5. Statistical Analysis Laboratory, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
6. Oral Cancer Research and Co-ordinating Centre (OCRCC), Faculty of Dentistry, University of Malaya, Subang Jaya, Malaysia
7. Department of Oral and Maxillofacial Pathology, Radiology and Medicine, New York University College of Dentistry, New York, NY, USA
8. Menzies Health Institute Queensland and School of Dentistry and Oral Health, Griffith University, Queensland, Australia