1. Department of Periodontology, School of Dentistry, Adnan Menderes University, Aydın, Turkey.
2. Department of Periodontology, School of Dentistry, Ege University, İzmir, Turkey.
3. Department of Biostatistics and Medical Informatics, School of Medicine, Ege University, İzmir, Turkey.
4. Department of Dental Medicine, Karolinska Instiute, Stockholm, Sweden.