1. Department of Orthodontics; Institute of Odontology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
2. Department of Periodontology and Oral Mucosa Diseases; Medical University of Warsaw; Warsaw Poland
3. Department of Periodontology; Institute of Odontology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
4. Department of Orthodontics; Medical University of Warsaw; Warsaw Poland