1. Division of Periodontology, Department of Oral Medical Science, Faculty of Dentistry and Research Group of Chronic Inflammatory Oral Diseases and Systemic Diseases Associated with Oral Health, Khon Kaen University, Khon Kaen, Thailand
2. Division of Periodontology, Department of Oral Medical Science, Faculty of Dentistry, Khon Kaen University, Khon Kaen 40002, Thailand
3. Division of Community Dentistry, Department of Oral Prevention Faculty of Dentistry, Khon Kaen University, Khon Kaen 40002, Thailand
4. Institute of Dentistry, Suranaree University of Technology, Nakhon Ratchasima, Thailand