1. University of Belgrade, Faculty of Dental Medicine, Belgrade, Serbia + University of Belgrade, Clinic for Oral Surgery, Belgrade, Serbia
2. University of Belgrade, Faculty of Dental Medicine, Belgrade, Serbia
3. University of Belgrade, Faculty of Dental Medicine, Belgrade, Serbia + University of Belgrade, Department of Medical Statistics and Informatics, Belgrade, Serbia
4. Military Medical Academy, Dental Clinic, Belgrade, Serbia + University of Defence, Faculty of Medicine of the Military Medical Academy, Belgrade, Serbia