ABSTRACT
Objective To study the clinical value of Time self -locking brackets in relieving the changes of dental arch and tooth morphology after maxillary dentition crowding .Methods From January 2015 to December 2015,80 patients with maxillary dentition in Rizhao Central Hospital were randomly divided into two groups according to the random number method ,with 40 cases in each group.The control group was treated with traditional MBT straight wire brackets (3M Company).The observation group was treated with Time self -locking brackets.And the width of the two groups was compared before and after the intervention.The treatment time and the incidence of complications during the treatment were observed in the two groups.Results After intervention,the width of canine and the length of long,middle bow in the observation group were significantly better than those in the control group ( t＝7.901, 29.820,15.652,all P＜0.05).The treatment time of the observation group was significantly shorter than that of the control group (t＝41.716,P＝0.000＜0.05).The incidence rate of bleeding ,swelling and loosening in the observa-tion group was significantly lower than that in the control group (χ2＝5.212,P＜0.05).The bracket shedding rate in the observation group was significantly lower than that in the control group ( χ2＝5.600,P＜0.05).Conclusion Time self-locking brackets is effective in the treatment of maxillary dentition crowding.The method has the advantages of high effect,simple clinical treatment ,less complication and low shedding rate during treatment.