Survival of maxillary and mandibular bonded retainers 10 to 15 years after orthodontic treatment: a retrospective observational study

Kocher, Katharina; Gebistorf, Meret; Pandis, Nikolaos; Fudalej, Piotr; Katsaros, Christos (2019). Survival of maxillary and mandibular bonded retainers 10 to 15 years after orthodontic treatment: a retrospective observational study. Progress in orthodontics, 20(1), p. 28. Springer 10.1186/s40510-019-0279-8

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Background: The long-term evidence regarding failures of fixed retainers is limited and the aim of this cohort study
was to assess the long-term risk of failure of one type of maxillary and two types of mandibular fixed lingual retainers.
Trial design: Retrospective cohort study.
Methods: Eighty-eight patients in retention 10–15 years after orthodontic treatment were included. The type of failure;
number of failures per tooth, per patient, and retainer; and adverse effects were assessed by (1) a questionnaire, (2)
clinical examination, and (3) screening patients’ clinical charts. Descriptive statistics were calculated and a Cox
regression was used to assess possible predictors for mandibular retainer survival.
Results and conclusions: In the mandible, 47 (53.4%) .016″ × .022″ braided stainless steel retainers (SS) were bonded
to all six anterior teeth, and 41 (46.6%) .027″ β-titanium (TMA) retainers were bonded to the canines only. From the SS
retainers 40.4% and of the TMA retainers 61% had no failures during the whole observation period. SS failures per
retainer were 2.17 (3.15) vs. 0.66 (1.03) for TMA. The type of retainer was the only significant predictor for failure. In the
maxilla, 82 (93.2%) .016″ × .022″ braided SS retainers were bonded to all four incisors and six retainers (6.8%) to all six
anterior teeth. The latter group was not further analyzed due to the small sample size. From the retainers bonded to all
four incisors, 74.4% had no failure during the whole observation period. SS average number of failures per retainer
bonded to the four incisors was 1.14 (SD 2.93). Overall, detachments were the most frequent type of first failure
followed by composite damage. From the original mandibular retainers 98.9% and of the original maxillary retainers
97.6% were still in situ 10–15 years after debonding. No adverse torque changes were observed.
Limitations: Potential effects of selection bias, information bias, and attrition bias as well as possible confounding
factors cannot be fully excluded in this study.
Keywords: Retention, Long-term retention, Fixed retainers, Retainer failure, Bond failure, Adverse effects

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > School of Dental Medicine > Department of Orthodontics

UniBE Contributor:

Kocher, Katharina, Gebistorf, Meret, Pandis, Nikolaos, Fudalej, Piotr, Katsaros, Christos


600 Technology > 610 Medicine & health








Renate Imhof-Etter

Date Deposited:

30 Jul 2019 14:35

Last Modified:

05 Dec 2022 15:29

Publisher DOI:


PubMed ID:





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