1. Department of Oro-Maxillofacial Surgical and Medical Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia
2. Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
3. Department of Diagnostic and Integrated Dental Practice, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia