Related Experiment Video
Updated: May 25, 2026
Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition
Published on: February 23, 2024
[Clinical evaluation of lingual fixed retainer combined with Hawley retainer and vacuum-formed retainer]
Xiao-cen Xu1, Ren-mei Li, Guo-hua Tang
1Department of Orthodontics, Shanghai Tenth People's Hospital, Shanghai Tongji University School of Medicine, Shanghai 200072,China. xu_xcen@126.com
Purpose:
To evaluate the clinical efficacy of vacuum-formed retainers (VFRs) and lingual fixed retainers combined with Hawley retainers (combined retainers, CRs).
Methods:
Forty five patients immediately after orthodontic treatment were randomly allocated to either VFRs (n=25) or CRs (n=20) groups. Overbite, overjet and calculus index scores (CIS) were recorded at pretreatment (T0), debonding (T1), 6 months (T2) and 12 months (T3) after maintenance. The tooth rotation, intercanine and intermolar width, and Little's index of irregularity were recorded on the study models of lower arches. The difference between the two groups was analyzed with SAS 6.12 software package.
Results:
No significant difference was noted during retention time in VFRs(P>0.05). Likewise, there was no significant difference between VFRs and CRs, except that the change of CIS in CRs was significantly larger than those in VFRs(P<0.05). The incidence of breakage of vacuum-formed retainers was 24<, which was comparable with that of lingual fixed retainers (20<).
Conclusions:
Both vacuum-formed retainers and lingual fixed retainers combined with Hawley retainers have good retention during the first 12-month retention period. Considering patients' compliance and retention efficacy, lingual fixed retainer with Hawley retainer at night is a better choice for retention.
