1. Department of Periodontology; School of Dentistry; Dental Science Research Institute; Chonnam National University; Gwangju Korea
2. Department of Preventive Medicine; Chonnam National University Medical School; Gwangju Korea
3. Jeonnam Regional Cancer Center; Chonnam National University Hwasun Hospital; Hwasun Korea
4. Department of Preventive Medicine & Institute of Wonkwang Medical Science; Wonkwang University School of Medicine; Iksan Korea
5. Department of Oral Pathology; School of Dentistry; Dental Science Research Institute; Chonnam National University; Gwangju Korea