Poor oral health as a risk factor for esophageal squamous dysplasia in northeastern Iran.

BACKGROUND Northeastern Iran has one of the highest rates of esophageal squamous cell carcinoma (ESCC) in the world. The reasons for observing such high rates of ESCC in this area are not fully clear. The current study evaluates the association between some potential risk factors and squamous dysplasia, a precursor lesion of ESCC, in northeastern Iran. MATERIALS AND METHODS Using logistic regression, we compared potential risk factors of ESCC in 124 individuals with dysplasia and 50 normal individuals from northeastern Iran. Case/control status was histologically proven in all 174 study participants. RESULTS Poor oral health showed a dose-response association with ESCC risk (p for trend < 0.01). Edentulous individuals had 5-fold higher risk of dysplasia compared to participants with good oral health (p-value < 0.01). CONCLUSION Our results are consistent with two other published studies that have shown oral health as a risk factor for ESCC. The high incidence of ESCC in northeastern Iran may be partly attributable to poor oral health.