1. Department of Oral and Maxillofacial Radiology, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.
2. Research Center for Modeling of Noncommunicable Diseases, Department of Epidemiology and Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
3. Department of Endodontic, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.