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Hallman, Mats
Publications (2 of 2) Show all publications
Krämer, A., Sjöström, M., Apelthun, C., Hallman, M. & Feldmann, I. (2023). Post-treatment stability after 5 years of retention with vacuum-formed and bonded retainers: a randomized controlled trial. European Journal of Orthodontics, 45(1), 68-78
Open this publication in new window or tab >>Post-treatment stability after 5 years of retention with vacuum-formed and bonded retainers: a randomized controlled trial
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2023 (English)In: European Journal of Orthodontics, ISSN 0141-5387, E-ISSN 1460-2210, Vol. 45, no 1, p. 68-78Article in journal (Refereed) Published
Abstract [en]

Background: Retention after orthodontic treatment is still a challenge and more evidence about post-treatment stability and patients’ perceptions of different retention strategies is needed.

Objectives: This trial compares removable vacuum-formed retainers (VFR) with bonded cuspid-to-cuspid retainers (CTC) after 5 years of retention.

Trial design: A single centre two-arm parallel-group randomized controlled trial.

Methods: This trial included 104 adolescent patients, randomized into two groups (computer-generated), using sequentially numbered, opaque, and sealed envelopes. All patients were treated with fixed appliances in both jaws with and without tooth extractions. Patients in the intervention group received a VFR in the mandible (n = 52), and patients in the active comparator group received a CTC (n = 52). Both groups had a VFR in the maxilla. Dental casts at debond (T1), after 6 months (T2), after 18 months (T3), and after 5 years (T4) were digitized and analysed regarding Little’s Irregularity Index (LII), overbite, overjet, arch length, and intercanine and intermolar width. The patients completed questionnaires at T1, T2, T3, and T4.

Results: Post-treatment changes between T1 and T4 in both jaws were overall small. In the maxilla, LII increased significantly (median difference: 0.3 mm), equally in both groups. In the mandible, LII increased significantly in the group VFR/VFR (median difference: 0.6 mm) compared to group VFR/CTC (median difference: 0.1 mm). In both groups, overjet was stable, overbite increased, and arch lengths decreased continuously. Intercanine widths and intermolar width in the mandible remained stable, but intermolar width in the maxilla decreased significantly. No differences were found between groups. Regardless of retention strategy, patients were very satisfied with the treatment outcome and their retention appliances after 5 years.

Limitations: It was not possible to perform blinded assessments of digital models at follow-up.

Conclusions: Post-treatment changes in both jaws were small. Anterior alignment in the mandible was more stable with a bonded CTC retainer compared to a removable VFR after 5 years of retention. Patients were equally satisfied with fixed and removable retention appliances.

Trial registration: ClinicalTrials.gov (NCT03070444).Issue

Section:Randomized Controlled Trial (RCT)

Place, publisher, year, edition, pages
Oxford University Press, 2023
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-198630 (URN)10.1093/ejo/cjac043 (DOI)000840414200001 ()35968668 (PubMedID)2-s2.0-85146463354 (Scopus ID)
Available from: 2022-08-15 Created: 2022-08-15 Last updated: 2023-07-13Bibliographically approved
Krämer, A., Sjöström, M., Hallman, M. & Feldmann, I. (2021). Vacuum-formed retainers and bonded retainers for dental stabilization: a randomized controlled trial. Part II: patients' perceptions 6 and 18 months after orthodontic treatment. European Journal of Orthodontics, 43(2), 136-143
Open this publication in new window or tab >>Vacuum-formed retainers and bonded retainers for dental stabilization: a randomized controlled trial. Part II: patients' perceptions 6 and 18 months after orthodontic treatment
2021 (English)In: European Journal of Orthodontics, ISSN 0141-5387, E-ISSN 1460-2210, Vol. 43, no 2, p. 136-143Article in journal (Refereed) Published
Abstract [en]

OBJECTIVE: To compare removable vacuum-formed Essix C retainers with bonded cuspid-to-cuspid retainers (CTCs) regarding patients' perceptions after debonding and 6 and 18 months of retention.

TRIAL DESIGN: A single-centre two-arm parallel-group randomized controlled trial.

METHODS: This trial included 104 adolescent patients, computer-generated randomized, with sequentially numbered, opaque and sealed envelopes, into two groups and stratified by gender. They were treated with fixed appliances with and without tooth extractions in both jaws and were ready for debond. Patients in the intervention arm received a vacuum-formed retainer (VFR) in the mandible (n = 52), and patients in the active comparator arm received a CTC (n = 52). Both groups had a VFR in the maxilla. Treatment outcome satisfaction, quality of care and attention, side-effects during the retention phase, and retainer acceptance and compliance were assessed with questionnaires at baseline (T1, 2 weeks after debond) and after 6 (T2) and 18 months (T3) of retention. Operator was blinded to group assignment during measurements.

RESULTS: Ninety-five patients completed the questionnaires at all three time points. Patients were overall satisfied with treatment outcome, quality of care and attention, and how their retainers worked at all three time points, with no differences between groups. At T1 and T3, the VFR group reported significantly more pain and discomfort (T1: P = 0.005, T3: P < 0.0001) and soreness (T1: P = 0.001, T3: P = 0.011) in the mandible compared to the CTC group. The CTC group found it easier to get used to their retainers. After 18 months, 70.5 per cent in the VFR group and 73.9 per cent in the CTC group reported the recommended wear-time of the VFRs. Decreased wear-time was correlated to perceived pain and discomfort (rs = -0.421, P < 0.0001).

LIMITATIONS: The results were limited by our retainer design and recommended wear regimen.

CONCLUSIONS: Both groups reported high treatment outcome satisfaction and low levels of side-effects during the retention phase. Nevertheless, the VFR group reported more pain and discomfort at T1 and at T3. Self-reported compliance was the same in both groups. The VFR group was more concerned about relapse.

TRIAL REGISTRATION: NCT03070444 (https://clinicaltrials.gov).

Place, publisher, year, edition, pages
Oxford University Press, 2021
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-182581 (URN)10.1093/ejo/cjaa039 (DOI)000648939600003 ()2-s2.0-85104047177 (Scopus ID)
Available from: 2021-05-03 Created: 2021-05-03 Last updated: 2023-09-05Bibliographically approved
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