Seeking adverse effects in systematic reviews of orthodontic interventions: a cross-sectional study (part 1).

BACKGROUND: Systematic reviews that assess the benefits of interventions often do not completely capture all dimensions of the adverse effects. This cross-sectional study (part 1 of 2 studies) assessed whether adverse effects were sought, whether the findings on these effects were reported, and what types of adverse effects were identified in systematic reviews of orthodontic interventions. METHODS: Systematic reviews of orthodontic interventions on human patients of any health status, sex, age, and demographics, and socio-economic status, in any type of setting assessing any type of adverse effect scored at any endpoint or timing were eligible. The Cochrane Database of Systematic Reviews and 5 leading orthodontic journals were manually searched for eligible reviews between August 1 2009 and July 31 2021. Study selection and data extraction was conducted by two researchers independently. Prevalence proportions were calculated for four outcomes on seeking and reporting of adverse effects of orthodontic interventions. Univariable logistic regression models were used to determine the association between each one of these outcomes and the journal in which the systematic review was published using the eligible Cochrane reviews as reference. RESULTS: Ninety-eight eligible systematic reviews were identified. 35.7% (35/98) of reviews defined seeking of adverse effects as a research objective, 85.7% (84/98) sought adverse effects, 84.7% (83/98) reported findings related to adverse effects, and 90.8% (89/98) considered or discussed potential adverse effects in the review. Reviews in the journal Orthodontics and Craniofacial Research compared with Cochrane reviews had approximately 7 times the odds (OR 7.20, 95% CI 1.08 to 47.96) to define seeking of adverse effects in the research objectives. Five of the 12 categories of adverse effects accounted for 83.1% (162/195) of all adverse effects sought and reported. CONCLUSIONS: Although the majority of included reviews sought and reported adverse effects of orthodontic interventions, end-users of these reviews should beware that these findings do not give the complete spectrum on these effects and that they could be jeopardized by the risk of non-systematically assessing and reporting of adverse effects in these reviews and in the primary studies that feed them. Much research is ahead such as developing core outcome sets on adverse effects of interventions for both primary studies and systematic reviews.

Spin on adverse effects in abstracts of systematic reviews of orthodontic interventions: a cross-sectional study (part 2).

BACKGROUND: It is critical that abstracts of systematic reviews transparently report both the beneficial and adverse effects of interventions without misleading the readers. This cross-sectional study assessed whether adverse effects of interventions were reported or considered in abstracts of systematic reviews of orthodontic interventions and whether spin on adverse effects was identified when comparing the abstracts with what was sought and reported in these reviews. METHODS: This cross-sectional study (part 2 of 2) used the same sample of 98 systematic reviews orthodontic interventions as used in part 1. Eligible reviews were retrieved from the Cochrane Database of Systematic Reviews and the 5 leading orthodontic journals between August 1 2009 and July 31 2021. Prevalence proportions were sought for 3 outcomes as defined in the published protocol. Univariable logistic regression models were built to explore associations between the presence of spin in the abstract and a series of predictors. Odds ratios (OR) 95% confidence intervals (95% CI) were used to quantify the strength of associations and their precision. RESULTS: 76.5% (75/98) of eligible reviews reported or considered (i.e., discussed, weighted etc.) potential adverse effects of orthodontic interventions in the abstract and the proportion of spin on adverse effects was 40.8% (40/98) in the abstract of these reviews. Misleading reporting was the predominant category of spin, i.e., 90% (36/40). Our explorative analyses found that compared to the Cochrane Database of Systematic Reviews all 5 orthodontic journals had similar odds of the presence of spin on adverse effects in abstracts of systematic reviews of orthodontic interventions. The odds of the presence of spin did not change over the sampled years (OR: 1.03, 95% CI: 0.9 to 1.16) and did not depend on the number of authors (OR: 0.93, 95% CI: 0.71 to 1.21), or on the type of orthodontic intervention (OR: 1.1, 95% CI: 0.45 to 2.67), or whether conflicts of interests were reported (OR: 0.74, 95% CI: 0.32 to 1.68). CONCLUSION: End users of systematic reviews of orthodontic interventions have to be careful when interpreting results on adverse effects in the abstracts of these reviews, because they could be jeopardized by uncertainties such as not being reported and misleading reporting as a result of spin.

Which orthodontic retention protocol should I implement? A critical assessment of a randomised controlled trial.

Trial design A single-centre two-arm parallel group randomised controlled trial.Objectives To assess differences in dental stability, patient perceptions and compliance and retainer failures in adolescents treated with vacuum-formed retainers (VFR) compared with those receiving bonded canine-to canine retainers after five years in retention.Methods In total, 104 eligible adolescents treated with fixed appliances in both jaws in a Swedish orthodontic clinic were randomised to two retention protocols. The intervention protocol consisted of a VFR covering all erupted teeth in the maxilla and a VFR in the mandible covering first premolar to first premolar. The controls received a VFR in the maxilla covering all erupted teeth and a bonded retainer wire to the lingual surfaces of the canines. The primary outcomes were various dental stability measures assessed at: debond (T1); six months (T2); 18 months (T3); and after five years (T4) in retention. Generalised estimating equations were used to quantify the effect of the different interventions on these outcome measures. One operator assessed all outcomes and participants could not be blinded. For the secondary outcomes, the perception and compliance with the retention protocols were assessed and the prevalence and rationale of retainer failure at T4. The trial was registered at ClinicalTrials.gov (NCT03070444) and the research project was supported by the Centre for Research and Development, Region Gävleborg, Sweden.Results Of the 104 randomised patients, 30 were not available at T4, leaving 35 patients in the intervention and 39 in the comparator group. An intention-to-treat analysis was used to impute outcomes for the missing patients. Post-treatment changes at T4 were small in both jaws. In the maxilla, the Little's Irregularity Index (LII) increased similar in both retention groups (median difference: 0.3 mm). In the mandible, the median difference for the LLI in the bonded retainer group was 0.1 mm compared with 0.6 mm in VFR group. In both retention protocols, the overjet remained stable, the overbite increased and the arch lengths continued to decrease. Intercanine and intermolar width remained stable in the mandible. Intermolar width decreased significantly in the maxilla. No differences in satisfaction were found between retention protocols after five years. Also, 72% of patients had stopped or rarely wore the VFR appliances at T4. Besides some retainer failures in both groups, no serious adverse effects associated with the retainers were reported.Conclusions Most post-treatment changes in both retention protocols were small in both jaws, except for the anterior alignment in the mandible, which was more stable in the bonded retainer group. This difference is possibly not related to the retention technique but to the poor compliance with the VFRs and the inclusion of adolescents only. Satisfaction with both protocols was similar.

Fixed orthodontic retainers and periodontal health.

Data sources The following electronic databases were searched from 1946 to 31 August 2019: Medline, Embase, the Cochrane Oral Health Group's Trials Register, CENTRAL, ClinicalTrials.gov, the National Research Register and Pro-Quest Dissertation Abstracts and Thesis database.Study selection The following study designs were eligible: randomised controlled trials (RCTs), controlled clinical trials, cohort studies of prospective and retrospective design, and cross-sectional studies that reported periodontal measurements on patients who received fixed retention after orthodontic therapy. Studies irrespective of their language were selected by two reviewers independently.Data extraction and synthesis Data extraction from the selected studies and risk of bias assessments were performed by two reviewers independently. Specific risk of bias tools were used according to the pertinent research designs of the included studies. Criteria for conducting a meta-analysis were not met and a qualitative synthesis was conducted.Results Twenty-nine studies fulfilled the eligibility criteria; that is, 11 RCTs, four prospective cohort studies, one retrospective cohort study and 13 cross-sectional studies. The quality of the evidence was low for most of the studies included in this review. Contrary to the general consensus, two RCTs, one prospective cohort study and two cross-sectional studies identified poorer periodontal health in patients with fixed orthodontic retainers.Conclusions The authors of this systematic review concluded that fixed orthodontic retainers in the majority of the 29 included studies seemed to be a method of retention that is rather compatible with periodontal health, or at least not related to severe detrimental consequences for the periodontium. No recommendations on the best type of fixed retainer to use could be given. High-quality evidence from long-term studies is necessary to provide definitive conclusions on the relationship between fixed retainers and periodontal health.

Seeking adverse effects in systematic reviews of orthodontic interventions: protocol for a cross-sectional study.

BACKGROUND: Before implementing healthcare interventions, clinicians need to weigh the beneficial and adverse effects of interventions. However, a large body of evidence has demonstrated that seeking and reporting of adverse effects is suboptimal in clinical trials and in systematic reviews of interventions. This cross-sectional study will investigate the status of this problem in orthodontics. This study will assess whether adverse effects were sought and whether findings related to adverse effects were reported in systematic reviews of orthodontic interventions in the five leading orthodontic journals and in the Cochrane Database of Systematic Reviews. METHODS: Systematic reviews of clinical orthodontic interventions published between 01 August 2009 and 31 July 2019 in the five leading orthodontic journals and in the Cochrane Database will be included. Empty reviews will be excluded. The reporting of outcomes on adverse effects will not determine eligibility, i.e., reviews will not be excluded, because they did not report usable data. Study selection and data extraction will be conducted independently by two authors. Our primary outcome will be the prevalence of systematic reviews of orthodontic interventions that sought any findings related to adverse effects in the included studies. Additional prevalence statistics will be calculated on a series of items related to seeking of adverse effects in the eligible reviews. All statistics will be calculated for (1) all journals together, (2) the group of five orthodontic journals and the Cochrane Database of Systematic Reviews separately, and (3) each individual journal separately. Chi-square tests of independence will be used to compare these groups. DISCUSSION: This study will assess whether adverse effects were sought in systematic reviews of orthodontic interventions. This knowledge is important, because reviews that present an incomplete picture on adverse effects can have unfavorable consequences for the end-users. Also not reporting that no adverse effects were assessed in eligible studies included in a systematic review can mislead pertinent stakeholders. Our findings could have policy implications for making judgments on accepting or rejecting an intervention systematic review for publication, for example, by directing editors and peer-reviewers to adopt the various items on adverse effects defined in the MECIR standards and in the PRISMA harm checklist.

Spin in the reporting, interpretation, and extrapolation of adverse effects of orthodontic interventions: protocol for a cross-sectional study of systematic reviews.

BACKGROUND: Titles and abstracts are the most read sections of biomedical papers. It is therefore important that abstracts transparently report both the beneficial and adverse effects of health care interventions and do not mislead the reader. Misleading reporting, interpretation, or extrapolation of study results is called "spin". In this study, we will assess whether adverse effects of orthodontic interventions were reported or considered in the abstracts of both Cochrane and non-Cochrane reviews and whether spin was identified and what type of spin. METHODS: Eligibility criteria were defined for the type of study designs, participants, interventions, outcomes, and settings. We will include systematic reviews of clinical orthodontic interventions published in the five leading orthodontic journals and in the Cochrane Database. Empty reviews will be excluded. We will manually search eligible reviews published between 1 August 2009 and 31 July 2019. Data collection forms were developed a priori. All study selection and data extraction procedures will be conducted by two reviewers independently. Our main outcomes will be the prevalence of reported or considered adverse effects of orthodontic interventions in the abstract of systematic reviews and the prevalence of "spin" related to these adverse effects. We will also record the prevalence of three subtypes of spin, i.e., misleading reporting, misleading interpretation, and misleading extrapolation-related spin. All statistics will be calculated for the following groups: (1) all journals individually, (2) all journals together, and (3) the five leading orthodontic journals and the Cochrane Database of Systematic Reviews separately. Generalized linear models will be developed to compare the various groups. DISCUSSION: We expect that our results will raise the awareness of the importance of reporting and considering of adverse effects and the presence of the phenomenon of spin related to these effects in abstracts of systematic reviews of orthodontic interventions. This is important, because an incomplete and inadequate reporting, interpretation, or extrapolation of findings on adverse effects in abstracts of systematic reviews can mislead readers and could lead to inadequate clinical practice. Our findings could result in policy implications for making judgments about the acceptance for publication of systematic reviews of orthodontic interventions.