marieh honarmand oral and dental disease research centre, department of oral medicine, school of dentistry, zahedan university of medical sciences, zahedan, ir iran shirin saravani oral and dental disease research centre, department of oral and maxillofacial pathology, school of dentistry, zahedan university of medical sciences, zahedan, ir iran; oral and dental disease research centre, department of oral and maxillofacial pathology, school of dentistry, zahedan university of medical sciences, zahedan, ir iran. tel: +98-5433441814, fax: +98-5433414003 nazanin kamyab department of oral medicine, school of dentistry, rafsanjan university of medical sciences, rafsanjan, ir iran mehdi jahantigh department of pathology, school of medicine, zahedan university of medical sciences, zahedan, ir iran molouk torabi parizi department of oral and maxillofacial pathology, school of dentistry, kerman university of medical sciences, kerman, ir iran