| Objective:To evaluate the clinical effects of lingual fixed retainers combined with vacuumformed retainers(combined retainers,hereinafter referred to as CRs)and Hawley retainers(hereinafter referred to as HRs).Methods:60 patients after orthodontic treatment over 1 year are chosen(include 35 patients used CRs and 25 patients used HRs).The patients are taken photos and impressions and the impressions(T1)will be contrasted with the impressions been taken when finished the orthodontic trement(T0).We need contrast five aspects.1)The Little’s index of anterior teeth on the study models of lower arches.2)Overbite,and overjet of the anterior teeth.3)The breadth of the canine and the first molar on the study models of upper arches.4)the length of the arches.5)The change of the torque in the anterior tooth.The difference between the two groups was analyzed.Results:No significant difference was found during retention time including overbite,and overjet of the anterior teeth,the breadth of the canine and the first molar on the study models of upper arches,the length of the arches and the change of the torque in the anterior tooth in CRs and HRs(p>0.05)However,the Little’s index of anterior tooth on the study models of lower arches is different between in CRs and HRs(p<0.05).Conclusion:Both CRs and HRs have good retentive effect during the retention period of the first 12-month.It shows in the following aspects:overbite,and overjet of the anterior teeth,the breadth of the canine and the first molar on the study models of upper arches、the length of the arches and the change of the torque in the anterior tooth.However,the neatness of anterior tooth is different between in in CRs and HRs during the retention period of the first 12-month.Meanwhile,the vacuum-formed retainers and the lingual fixed retainers can mutually "help" and "supervise" each other. |
