1. Department of Periodontology, Witten/Herdecke University Faculty of Health, Witten, Germany.
2. Department of Periodontology, Altınbaş University Faculty of Dentistry, Istanbul, Turkey.
3. Department of Orthodontics, Oral Biology Laboratory, University of Bonn, Bonn, Germany.
4. Department of Periodontology, Dankook University College of Dentistry, Seoul, Korea.
5. Clinic of Conservative and Preventive Dentistry, Division of Periodontology and Peri-implant Diseases, University of Zurich, Zürich, Switzerland.