1. Department of Periodontics and Dental Hygiene, University of Texas Health Science Center at Houston, Houston, TX, USA
2. Department of Periodontics, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA
3. Department of Periodontology, Dental Research Institute, School of Dentistry, Chonnam National University, Gwangju, Republic of Korea
4. Department of Periodontology, Implantology Institute, Lisbon, Portugal
5. Department of Pathology, School of Dentistry, Nihon University at Matsudo, Chiba, Japan
6. Division of Diagnostic Pathology, Nihon University Hospital School of Dentistry at Matsudo, Chiba, Japan