Considering the adverse effects of the gingival recession, the aim of this study was to determine the prevalence and causes of mandibular incisors gingival recession in students aged 6-12 years, in Hamadan, Iran. In this crosssectional study, a sample of 1200 students were randomly selected. Demographic data (age and gender), tooth type, clinical crown length and form, keratinized gingiva width, frenal involvement, dental plaque, gingivitis, manner and frequency of brushing per day, anterior crowding and history of orthodontic treatment were variables which their association with gingival recession were examined. The prevalence of the gingival recession was 18.25 percent. The prevalence was higher among female in comparison with male children and was increased, as age increased. The majority of children with gingival recession did not applied a correct technique of brushing. All the variables investigated in the present study such as tooth type and clinical crown length, manner and frequency of brushing had a significant association with the occurrence of the gingival recession (p-value<0.05). Several factors are associated with gingival recession. High prevalence of this disorder, its complications and the fact that its prevalence increases with students aging, make the design and implementation of training programs for students and their parents essential to prevent gingival recession.
