1. Department of Pedodontics and Preventive Dentistry, Dentistry School, Medical Faculty, University of Prishtina, Prishtina, Kosovo.
2. Department of Periodontology and Oral Medicine, Dentistry School, Medical Faculty, University of Prishtina, Prishtina, Kosovo.
3. 8032 Zürich, Switzerland.
4. National Institute of Public Health, Department of Statistic, Medical Faculty, University of Prishtina, Prishtina, Kosovo.
5. Department of Prosthodontics, University of Aachen, Germany.