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.

The effectiveness of surgical adjunctive procedures in the acceleration of orthodontic tooth movement: A systematic review of systematic reviews and meta-analysis.

OBJECTIVE: To identify and evaluate the body of the evidence regarding the effectiveness of surgical adjunctive procedures (SAPs) in accelerating orthodontic tooth movement (OTM). DATA SOURCES: Unrestricted search of three electronic databases and manual search up to 12 June 2020 were undertaken. DATA SELECTION: All systematic reviews of randomised and non-randomised controlled trials that investigate the effectiveness of the SAPs in accelerating OTM were included. DATA EXTRACTION: Study selection and data extraction were undertaken independently and in duplicate by two reviewers. A random-effects model with a 95% confidence interval (CI) was generated for comparable outcomes. Two reviewers assessed the quality of the included studies using AMSTAR2 and GRADE. RESULTS: Fourteen systematic reviews were included; however, four systematic reviews were assessed quantitatively. Meta-analysis showed that mean difference (MD) of canine retraction rate, for the first month after SAPs, was mild (MD = 0.65 mm/month). Compared to control, micro-osteoperforations (MOPs) statistically but temporally accelerate lower canine retraction and en masse retraction by 0.25 mm/month and 0.31 mm/month, respectively. There was no significant effect (P>0.05) in terms of molar anchorage loss (MAL) between control and MOP groups. Piezocision non-significantly shortens the duration of en masse retraction (4.30 months, P>0.05), but significantly shortens incisors retraction (101.64 days, P<0.001). MAL is mild but significantly less in the piezocision group compared to the control group (MD = 0.53 mm, P=0.03). Low-level evidence showed that SAPs have no significant effect on root resorption or periodontal health; however, piezocision is associated with transient acute inflammation and noticeable scars. CONCLUSION: Low-level evidence concludes that SAPs accelerate OTMs and reduce treatment duration, but the acceleration is minor and transient. The effect on anchorage loss is variable and technique related. Side effects of SAPs are transient, but some might be aesthetically noticeable. A cost-benefit analysis of SAPs should be considered while making the treatment decision.

Assessment of the apically extruded debris between a rotary system, a reciprocating system and hand files during the root canal instrumentation of the deciduous molars.

BACKGROUND: One of the factors that most negatively affect the endodontic instrumentation process in primary teeth is the presence of extruded debris in the periapical region. Therefore, different techniques have been evaluated to reach an answer to the question regarding which root canal preparation method produces the least amount of debris extrusion. OBJECTIVES: The main objective of this study was to assess the amount of debris extrusion as well as irrigation associated with 3 different instrumentation techniques: a rotary system (PROTAPER NEXT® - PTN), a reciprocating system (WaveOne® - WO) and hand K-files. MATERIAL AND METHODS: Forty-eight primary mandibular molars with a single distal canal were selected and randomly divided into 3 groups (n = 16). Three different techniques were used for the canal instrumentation of each group, comprising PTN, WO and hand K-files. Pre-weighed Eppendorf tubes were used for the collection of debris extrusion, then stored in an incubator at 70°C for 5 days. A one-way analysis of variance (ANOVA) test was used for data analysis, followed by Tukey's post hoc test. RESULTS: Statistically significant differences were found while comparing the PTN and WO systems with the hand files. Both PTN and WO showed less debris extrusion toward the periapical tissues than the hand files. Still, no statistically significant differences were seen between the PTN and WO groups. CONCLUSIONS: Generally, debris extrusion occurred in all of the 3 experimental groups. The PTN and WO systems showed the least debris extrusion as compared to the hand files during the root canal instrumentation of the primary teeth, and for these reasons along with the shorter operating time, it may be concluded that using rotary and reciprocating systems rather than manual files is highly advisable. However, a clinical assessment is suggested.

Effect of molar intrusion with temporary anchorage devices in patients with anterior open bite: a systematic review.

OBJECTIVE: The objective of the study is to assess the effect of molar intrusion with temporary anchorage devices on the vertical facial morphology and mandibular rotation during open bite treatment in the permanent dentition. METHODS: We performed a systematic review of the published data in seven electronic databases up to September 2015. We considered studies for inclusion if they were examining the effects of posterior teeth intrusion on the vertical facial morphology with open bite malocclusion in the permanent dentition. Study selection, risk of bias assessment, and data-extraction were performed in duplicate. Meta-analysis was not possible due to dissimilarity and heterogeneity among the included studies. RESULTS: Out of the 42 articles that met the initial eligibility criteria, 12 studies were finally selected. Low level of scientific evidence was identified after risk of bias assessment of the included studies with no relevant randomized controlled trial performed. Out of the 12 selected studies, five studies used miniplates and seven studies used miniscrews. Mandibular counterclockwise rotation was found to be between 2.3° and 3.9° in six studies (as sassed by mandibular plane angle, between MeGo or GoGn and SN or FH plane) while it was less than 2° in the remaining studies. CONCLUSIONS: Current weak evidence suggests that molar intrusion with temporary anchorage devices may cause mandibular counterclockwise autorotation. Future well-conducted and clearly reported multicenter randomized controlled trials that include a non-treatment control group are needed to make robust recommendations regarding the amount of mandibular rotation during open bite treatments.