[1] Department of Paediatric, Orthodontic and Preventive Dentistry, Mosul University School of Dentistry, Mosul
[2] Department of Paediatric Dentistry, Indiana University School of Dentistry, Indianapolis, IN, 46202
[3] Directorate of Nineveh Health, Mosul
[4] Department of Biostatistics, Indiana University School of Medicine, Indianapolis, IN