Early detection of teeth at risk of severe resorption is crucial.At present, using radiographs is common but detecting only resorption after 60-70% of the mineralized tissue is already lost. Moreover, they only provide two-dimensional information, identifying apical change primarily. Also, radiographs cannot indicate if the process of root resorption is still active for monitoring its progress and additional radiation exposure to the patient will be needed. Therefore, a safer, more reliable alternative method to clinically diagnose early stages of root resorption is needed and may include detecting biomarkers in gingival crevicular fluid. Furthermore, the relationship between the manner of orthodontic force application and orthodontically induced root resorption is under study. It has been suggested that pausing orthodontic forces during treatment may reduce the amount of root resorption, likely due to cementum repair during the inactive period. This is important specifically in individuals who are biologically and genetically prone to root resorption. The aim of the study is to compare the extent of root resorption between controlled continuous and intermittent orthodontic forces using levels of dentin phosphoprotein in gingival crevicular fluid.