Otorhinolaryngology Research Center, Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran. Clinical Research Development Unit of Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran. Electronic address: ashraf_adr@yahoo.com. Department of General Surgery, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran. General medical student, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.