1. Otorhinolaryngology Research Center, Department of Otolaryngology Head and Neck Surgery, Tehran University of Medical Sciences, Amir A’lam Hospital, Tehran, Iran
2. Faculty of Health, Department of Epidemiology and Biostatistics, Qom University of Medical Sciences, Qom, Iran
3. School of Dentistry, Shahid Beheshti University, Tehran, Iran
4. Digestive Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran