Reporting of the methodological quality of search strategies in orthodontic quantitative systematic reviews

Language bias in orthodontic systematic reviews: A meta-epidemiological study

BACKGROUND

Orthodontic systematic reviews (SRs) include studies published mostly in English than non-English languages. Including only English studies in SRs may result in a language bias. This meta-epidemiological study aimed to evaluate the language bias impact on orthodontic SRs.

DATA SOURCE

SRs published in high-impact orthodontic journals between 2017 and 2021 were retrieved through an electronic search of PubMed in June 2022. Additionally, Cochrane oral health group was searched for orthodontic systematic reviews published in the same period.

DATA COLLECTION AND ANALYSIS

Study selection and data extraction were performed by two authors. Multivariable logistic regression was implemented to explore the association of including non-English studies with the SRs characteristics. For the meta-epidemiological analysis, one meta-analysis from each SRs with at least three trials, including one non-English trial was extracted. The average difference in SMD was obtained using a random-effects meta-analysis.

RESULTS

174 SRs were included in this study. Almost one-quarter (n = 45/174, 26%) of these SRs included at least one non-English study. The association between SRs characteristics and including non-English studies was not statistically significant except for the restriction on language: the odds of including non-English studies reduced by 89% in SRs with a language restriction (OR: 0.11, 95%CI: 0.01 0.55, P< 0.01). Out of the sample, only fourteen meta-analyses were included in the meta-epidemiological analysis. The meta-epidemiological analysis revealed that non-English studies tended to overestimate the summary SMD by approximately 0.30, but this was not statistically significant when random-effects model was employed due to substantial statistical heterogeneity (ΔSMD = -0.29, 95%CI: -0.63 to 0.05, P = 0.37). As such, the overestimation of meta-analysis results by including non-English studies was statistically non-significant.

CONCLUSION

Language bias has non-negligible impact on the results of orthodontic SRs. Orthodontic systematic reviews should abstain from language restrictions and use sensitivity analysis to assess the impact of language on the conclusions, as non-English studies may have a lower quality.

Interventions to facilitate the successful eruption of impacted maxillary incisor teeth due to the presence of a supernumerary: A systematic review and meta-analysis

INTRODUCTION

A failure of maxillary incisor eruption is commonly attributed to the presence of a supernumerary tooth. This systematic review aimed to assess the percentage of impacted maxillary incisors that successfully erupt after surgical removal of supernumerary teeth with or without other interventions.

METHODS

Systematic literature searches without restrictions were undertaken in 8 databases for studies reporting any intervention aimed at facilitating incisor eruption, including surgical removal of the supernumerary alone or in conjunction with additional interventions published up to September 2022. After duplicate study selection, data extraction, and risk of bias assessment according to the risk of bias in nonrandomized studies of interventions and Newcastle-Ottawa scale, random-effects meta-analyses of aggregate data were conducted.

RESULTS

Fifteen studies (14 retrospective and 1 prospective) were included with 1058 participants (68.9% male; mean age, 9.1 years). The pooled eruption prevalence for removal of the supernumerary tooth with space creation or removal of the supernumerary tooth with orthodontic traction was significantly higher at 82.4% (95% confidence interval [CI], 65.5-93.2) and 96.9% (95% CI, 83.8-99.9) respectively, compared with removal of an associated supernumerary only (57.6%; 95% CI, 47.8-67.0). The odds of successful eruption of an impacted maxillary incisor after removal of a supernumerary were more favorable if the obstruction was removed in the deciduous dentition (odds ratio [OR], 0.42; 95% CI, 0.20-0.90; P = 0.02); if the supernumeraries were conical (OR, 2.91; 95% CI, 1.98-4.28; P <0.001); if the incisor was in the correct position (OR, 2.19; 95% CI, 1.14-4.20; P = 0.02), at the level of the gingival third (OR 0.07; 95% CI, <0.01-0.97; P = 0.04) and had incomplete root formation (OR, 9.02; 95% CI, 2.04-39.78; P = 0.004). Delaying removal of the supernumerary tooth 12 months after the expected eruption time of the maxillary incisor (OR, 0.33; 95% CI, 0.10-1.03; P = 0.05) and waiting >6 months for spontaneous eruption after removal of the obstacle (OR, 0.13; 95% CI, 0.03-0.50; P = 0.003) was associated with worse odds for eruption.

CONCLUSIONS

Limited evidence indicated that the adjunctive use of orthodontic measures and removal of supernumerary teeth might be associated with greater odds of successfull impacted incisor eruption than removal of the supernumerary tooth alone. Certain characteristics related to supernumerary type and the position or developmental stage of the incisor may also influence successful eruption after removal of the supernumerary. However, these findings should be viewed with caution as our certainty is very low to low because of bias and heterogeneity. Further well-conducted and reported studies are required. The results of this systematic review have been used to inform and justify the iMAC Trial.

The effectiveness of interventions to increase patient involvement in decision-making in orthodontics: A systematic review

OBJECTIVES

To examine the effectiveness of interventions that aim to increase patient involvement in treatment decisions in orthodontic, orthognathic and cleft treatment, based on patient-reported outcomes and patient knowledge.

DESIGN

Systematic review.

DATA SOURCES

OVID databases (MEDLINE, EMBASE and EBM reviews), CENTRAL, WHO's International Clinical Trials Registry Platform and reference lists of included studies.

DATA SELECTION

Studies were selected by two reviewers independently and in duplicate based on pre-defined eligibility criteria: Population: People considering or undergoing orthodontic, orthognathic or cleft treatment. Intervention: Any intervention that aims to increase patient involvement in decision-making. Outcomes: Patient-reported outcomes and patient knowledge. Studies: All experimental studies published in English from January 2000 to October 2019 were eligible.

DATA EXTRACTION

Standardised data extraction of study information and assessment of risk of bias using the Cochrane Risk of Bias Tool for RCTs and ROBINS-I for non-randomised studies of interventions.

DATA SYNTHESIS

13 randomised controlled trials were included. Due to heterogeneity in the studies, a narrative synthesis was undertaken. The majority (n=11) of studies involved orthodontic patients, with one study of cleft patients and one study of orthognathic and orthodontic patients. Six included studies reported significant differences between intervention and control groups with improved patient knowledge or better patient-reported outcomes.

CONCLUSIONS

A variety of different interventions and outcome measures were used making data synthesis challenging. There is some evidence that interventions to increase patient involvement in decision-making can improve patient-reported outcomes and patient knowledge.