S M J Mortazavi1, S A R Mortazavi2, Maryam Paknahad3. 1. Medical Physics Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran. 2. Student of Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. 3. Oral and Maxillofacial Radiology Department, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. Electronic address: paknahadmaryam@yahoo.com.