1. Department of Oral and Maxillofacial Diseases, Head and Neck Center, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland
2. Department of Periodontics, Faculty of Dentistry, Universitas Gadjah Mada, Jalan Denta No.1 Sekip Utara, Sleman, Yogyakarta 55281, Indonesia
3. Department of Preventive Dentistry, Periodontology and Implant Biology, Faculty of Health Sciences, Dental School, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece
4. Dental Sector, 424 General Military Training Hospital, 564 29 Thessaloniki, Greece
5. Department of Pediatric Surgery, New Children’s Hospital, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland
6. Oral Health Sciences Centre, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
7. Department of Oral Diseases, Karolinska Institutet, 171 77 Stockholm, Sweden