1. Department of Stomatology, 3rd Faculty of Medicine, Charles University and Kralovske Vinohrady University Hospital, 10034 Prague, Czech Republic
2. Institute of Dentistry and Oral Sciences, Faculty of Medicine and Dentistry, Palacký University Olomouc, 77900 Olomouc, Czech Republic
3. Department of Pediatric Surgery, Institute of Mother and Child, 01-211 Warsaw, Poland
4. Faculty of Medicine in Pilsen, Charles University, 323 00 Pilsen, Czech Republic
5. Department of Orthodontics and Dentofacial Orthopedics, University of Bern, 3012 Bern, Switzerland
6. Department of Orthodontics, Jagiellonian University Cracow, 31-155 Krakow, Poland