1. Independent Unit of Epidemiology, Medical University of Lublin, Lublin, Poland
2. Independent Unit of Propaedeutics of Dentomaxillofacial Radiology, Medical University of Lublin, Lublin, Poland
3. Private Dental Practice, Warsaw, Poland
4. Department of Oral Surgery, University of Split School of Medicine and University Hospital Centre, Split, Croatia
5. AgEstimation Project, University of Macerata, Macerata, Italy