RESUMO
Objective:To Compare root resorption between T loop technique and sliding technique of orthodontic treatment.Meth-ods:90 patients with Angle class I malocclusion were orthodontically treated by MBT fixed appliances with T loop technique(n =45) and sliding technique(n =45)respectively.Root resorption of the patients were examined by grading evaluation method with orthopan-tomography and periapical films before and after orthodontic treatment.Results:After orthodontic treatment the tooth root resorption rate increased(P 0.05).Root resorption mostly occurred in the incisors,especially in mandibular tooth.Conclusion:There is no difference of the effect of root resorption between T loop technique and sliding technique of orthodontic treatment in patients with Angle class I malocclusion.