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 performance of artificial intelligence models in generating responses to general orthodontic questions: ChatGPT vs Google Bard.

INTRODUCTION: This study aimed to evaluate and compare the performance of 2 artificial intelligence (AI) models, Chat Generative Pretrained Transformer-3.5 (ChatGPT-3.5; OpenAI, San Francisco, Calif) and Google Bidirectional Encoder Representations from Transformers (Google Bard; Bard Experiment, Google, Mountain View, Calif), in terms of response accuracy, completeness, generation time, and response length when answering general orthodontic questions. METHODS: A team of orthodontic specialists developed a set of 100 questions in 10 orthodontic domains. One author submitted the questions to both ChatGPT and Google Bard. The AI-generated responses from both models were randomly assigned into 2 forms and sent to 5 blinded and independent assessors. The quality of AI-generated responses was evaluated using a newly developed tool for accuracy of information and completeness. In addition, response generation time and length were recorded. RESULTS: The accuracy and completeness of responses were high in both AI models. The median accuracy score was 9 (interquartile range [IQR]: 8-9) for ChatGPT and 8 (IQR: 8-9) for Google Bard (Median difference: 1; P <0.001). The median completeness score was similar in both models, with 8 (IQR: 8-9) for ChatGPT and 8 (IQR: 7-9) for Google Bard. The odds of accuracy and completeness were higher by 31% and 23% in ChatGPT than in Google Bard. Google Bard's response generation time was significantly shorter than that of ChatGPT by 10.4 second/question. However, both models were similar in terms of response length generation. CONCLUSIONS: Both ChatGPT and Google Bard generated responses were rated with a high level of accuracy and completeness to the posed general orthodontic questions. However, acquiring answers was generally faster using the Google Bard model.

Are units of analysis properly considered in orthodontic meta-analyses?

BACKGROUND: Assessment of unit of analysis (UoA) in meta-analysis with cluster, split-mouth, repeated measures designs, and multiple intervention groups is a fundamental step in the analysis. The objective of this study was to evaluate the UoAs in orthodontic meta-analysis and determine the error of the analysis. METHODS: An electronic search was conducted in the Cochrane Library and PubMed to identify orthodontic systematic reviews (SRs) with meta-analyses published in Cochrane and in the highest impact orthodontic journals between 1 January 2013 and 31 December 2022. SRs with meta-analysis assessing at least one of the following UoAs; cluster trials, crossover trials, multiple observations, or multiple intervention groups were included. Screening and data extraction were undertaken by two investigators independently. Descriptive statistics for the study characteristics were provided. The associations between avoiding the unit analysis error (yes, no) and the study characteristics were examined using Fisher's exact test and chi-square test. Logistic regression was undertaken for the significant predictors. RESULTS: Eighty SRs were deemed eligible for inclusion. Only 30 per cent of the included SRs avoided UoA errors. Compared to the split-mouth design, repeated measures designs had higher odds of avoiding UoA error (odds ratio: 9.6, 95% confidence interval: 2.8-32.3, P < 0.001). In contrast, fewer odds of avoiding the UoA error were found in the cluster design (OR: 0.2, 95% CI: 0.4-1.3, P = 0.09). Though multiple intervention groups have higher odds of avoiding UoA error than split-mouth studies, this was not statistically significant (OR: 2.1, 95% CI: 0.5-8, P = 0.28). None of the SRs characteristics have influenced the appropriate handling of the unit analysis except the type of the journal; the odds of avoiding the UoA error were higher in Cochrane reviews than the non-Cochrane reviews (OR: 3.3, 95% CI: 1.2-8.7, P = 0.02), and the number of authors (P < 0.05). CONCLUSIONS: UoA errors are common in orthodontic meta-analyses and were only partially avoided in split-mouth design, repeated measures design, and multiple intervention groups.

The efficacy of concentrated growth factor and platelet-rich fibrin as scaffolds in regenerative endodontic treatment applied to immature permanent teeth: a retrospective study.

BACKGROUND: The aim of this retrospective study was to compare the efficacy of concentrated growth factor (CGF) and platelet-rich fibrin (PRF) as scaffolds in regenerative endodontic therapy (RET). METHODS: Necrotic immature permanent teeth treated with regenerative endodontic therapy during January 2018 to August 2022 were divided into the CGF and PRF groups according to the scaffold. The CGF and PRF groups included 7 and 6 teeth, respectively. The efficacy of regenerative endodontic therapy was analyzed based on the clinical and radiological outcomes at three different follow up periods: T1 (3-6 months), T2 (6-12 months) and T3 (12-24 months). Statistical analysis was performed using the independent T test, Mann-Whitney test and Fisher's exact test at a significance level of 0.05. RESULTS: The success rate of each stage in both groups was 100%. Through quantitative comparison of radiographic outcomes, there was no statistically significant difference between the two groups in terms of root development and periapical lesion healing at each stage, except that the increase rate of radiographic root area in PRF group in the T3 stage was above one in CGF group with statistically significance. CONCLUSIONS: Both CGF and PRF had a similar clinical performance regarding resolution of clinical signs and symptoms, periapical lesion healing, and continued root development as scaffolds in RET. Further prospective studies with large samples for longer follow-up periods are needed.

Treatment Outcome of Regenerative Endodontic Procedures for Necrotic Immature and Mature Permanent Teeth: A Systematic Review and Meta-Analysis Based on Randomised Controlled Trials.

PURPOSE: To analyse whether the stage of apical development affects the effectiveness of regenerative endodontic treatment by comparing the outcomes for necrotic mature and immature permanent teeth treated with regenerative endodontic procedures. MATERIALS AND METHODS: Multiple databases (PubMed, Cochrane Library, Web of Science, EMBASE and OpenGrey databases) were searched through February 17th, 2022. Inclusion criteria were randomised controlled trials that included treatment of necrotic immature or mature permanent teeth using any regenerative endodontic procedures (REPs) that aimed to achieve pulp revascularisation or regeneration. The Cochrane Risk of Bias 2.0 tool was used to assess risk of bias. The included indicators were asymptomatic sign, success, pulp sensitivity, and discolouration. The extracted data were expressed by percentage for statistical analysis. The random effect model was used to explain the results. Comprehensive Meta-Analysis Version 2 was used to perform the statistical analyses. RESULTS: Twenty-seven RCTs were eligible for inclusion in the meta-analysis. The success rates of necrotic immature and mature permanent teeth were 95.6% (95% CI, 92.4%-97.5%; I2=34.9%) and 95.5% (95%CI, 87.9%-98.4%; I2=0%), respectively. The asymptomatic rates of necrotic immature and mature permanent teeth were 96.2% (95%CI, 93.5%-97.9%; I2=30.1%) and 97.0% (95%CI, 92.6%-98.8%; I2=0%), respectively. The treatment of immature and mature necrotic permanent teeth with REPs yields high success rates and low symptomatic rates. The incidence of positive sensitivity response for electric pulp testing in necrotic immature permanent teeth (25.2% [95% CI, 18.2%-33.8%; I2=0%]) was lower than that in necrotic mature permanent teeth (45.4% [95% CI, 27.2%-64.8%; I2=75.2%]), and this difference was statistically significant. The restoration of pulp sensitivity seems to be more evident in necrotic mature permanent teeth than in necrotic immature permanent teeth. The crown discolouration rate of immature permanent teeth was 62.5% (95% CI, 49.7%-73.8%; I2=76.1%). Necrotic immature permanent teeth have a considerable crown discolouration rate. CONCLUSION: REPs for both immature and mature necrotic permanent teeth yield high success rates and promote root development. The vitality responses seem to be more evident in necrotic mature permanent teeth than in necrotic immature permanent teeth.

The effect of early versus delayed space closure on the rate of orthodontic tooth movement: a systematic review and meta-analysis.

BACKGROUND: Orthodontic space closure of extraction sites can be initiated early, within 1-week post-extraction, or it can be delayed for a month or more. OBJECTIVE: This systematic review aimed to evaluate the effect of early versus delayed initiation of space closure after tooth extraction on the rate of orthodontic tooth movement. SEARCH METHODS: Unrestricted search of 10 electronic databases was conducted until September 2022. SELECTION CRITERIA: Randomized controlled trials (RCTs) investigating the initiation time of space closure of extraction sites in patients undergoing orthodontic treatment were included. DATA COLLECTION AND ANALYSIS: Data items were extracted using a pre-piloted extraction form. The Cochrane's risk of bias tool (ROB 2.0) and the Grading of Recommendations, Assessment, Development, and Evaluation approach were used for quality assessment. Meta-analysis was undertaken if there are at least two trials reporting the same outcome. RESULTS: Eleven RCTs met the inclusion criteria. Meta-analysis revealed that early canine retraction resulted in a statistically significant higher rate of maxillary canine retraction when compared to delayed canine retraction [mean difference (MD); 0.17 mm/month, 95% CI: 0.06 to 0.28, P = 0.003, 4 RCTs, moderate quality]. Duration of space closure was shorter in the early space closure group, but not statistically significant (MD; 1.11 months, 95% CI: -0.27 to 2.49, P = 0.11, 2 RCTs, low quality). The incidence of gingival invaginations was not statistically different between early and delayed space closure groups (Odds ratio; 0.79, 95% CI: 0.27 to 2.29, 2 RCTs, P = 0.66, very low quality). Qualitative synthesis found no statistically significant differences between the two groups regarding anchorage loss, root resorption, tooth tipping, and alveolar bone height. CONCLUSIONS: Based on the available evidence, early traction within the first week after tooth extraction has a minimal clinically significant effect on the rate of tooth movement compared to delayed traction. Further high-quality RCTs with standardized time points and measurement methods are still needed. REGISTRATION: PROSPERO (CRD42022346026).

Flash-free and conventional adhesive ceramic brackets in patients undergoing orthodontic treatment: A systematic review and meta-analysis.

To investigate whether flash-free adhesive ceramic brackets (FFA) have a better clinical performance than conventional adhesive ceramic brackets (CVA) in patients undergoing multi-bracket orthodontic treatment. PubMed, CENTRAL, Web of Science, Scopus, Embase, CNKI and Grey-literature were searched without restrictions up to January 2022. Both randomized controlled trials (RCTs) and controlled clinical trials (CCTs) were included. Risk of bias assessment was performed using the RoB 2.0 and ROBINS-I cochrane risk of bias tools. Eight articles, for seven studies, were included in this systematic review, and four split-mouth trials (SMT) were included in the meta-analysis. A random-effects meta-analysis found a statistically significant faster bonding time with FFA (mean difference [MD] = -93.85 seconds/quadrant, P = .002, 2 SMT), and no statistically significant difference regarding bracket failure rate at 6 months (risk ratio [RR] = 1.05; P = .93, 3 SMT), adhesive removal time (MD = -18.26 seconds/quadrant, P = .50, 2 SMT), and amount of remnant adhesive (MD = -0.13/bracket, P = .72, 2 SMT) between FFA and CVA. No difference (P > .05, 3 SMT) was found in enamel demineralization and periodontal measurements. CVA showed a statistically significant higher debonding pain score (P = .004, 1 SMT). Both flash-free and conventional adhesive ceramic brackets had a similar clinical performance, except for the faster bonding with FFA. Further, well-designed clinical trials are still required.

Effectiveness of platelet-rich concentrates on the rate of orthodontic tooth movement: a systematic review and meta-analysis.

BACKGROUND: Autologous platelet-rich concentrates (PRCs) are recently used as a local biological substance in orthodontics to accelerate the rate of tooth movement. OBJECTIVES: This systematic review aimed to evaluate the effects of PRCs on the rate of orthodontic tooth movement (OTM). SEARCH METHODS: Unrestricted search of five electronic databases supplemented by the manual and gray literature search were undertaken in March 2022. SELECTION CRITERIA: Randomized controlled trials (RCTs) evaluating the effect of PRCs on the rate of OTM with their side effect were included in this systematic review. DATA COLLECTION AND ANALYSIS: Data items were extracted by two authors using a pre-piloted extraction form. Similar outcomes within a comparable time frame were synthesized in a meta-analysis. RESULTS: Fourteen studies were deemed eligible for inclusion and seven RCTs were pooled in a meta-analysis. Canine retraction rate was higher in the side of PRCs injection than the control side by 0.28 mm/month (95% CI: 0.16-0.40, I2 = 95.6 per cent, P < 0.001, 345 patients) in the first 4 months after PRCs injection. There was no statistically significant difference between the PRCs side and the control side regarding molar anchorage loss (MAL) (MD = 0.03 mm, 95% CI: -0.18 to 0.24, I2 = 46.3 per cent, P = 0.78, 44 patients), canine rotation (MD = -0.19o, 95% CI: -1.95 to 1.57, I2 = 45.4 per cent, P = 0.96, 48 patients), or en-masse retraction. Likewise, there was no difference between both groups in terms of the duration of de-crowding. The mandibular canine retraction was statistically higher on the PRCs side than on the control side by 0.17 mm/month (P < 0.001, one trial). Regarding root resorption, there was no statistically significant difference between the experimental and control sides within the follow-up time. Mild pain scores were reported by the patients in the first 24 hours after injections. CONCLUSIONS: Low-level evidence indicates that the effect of PRCs on OTM is minor and clinically insignificant. The findings should be interpreted with caution due to the inherent limitations in the included RCTs. REGISTRATION: PROSPERO (CRD42022300026).

Effects of mouth breathing on maxillofacial and airway development in children and adolescents with different cervical vertebral maturation stages: a cross-sectional study.

BACKGROUND: To examine the influence of mouth breathing on maxillofacial and airway development in children and adolescents with different cervical vertebral maturation stages. METHODS: Lateral cephalometric radiograph of a total of 120 children and adolescents, 64 girls and 56 boys (7-15 years old), diagnosed with mouth breathing were examined. Maxillofacial hard tissue, soft tissue and airway measurements were obtained using both manual and digital techniques. Independent samples t-test was performed to compare the difference between the measured indexes and the standard values. RESULTS: As for maxillofacial hard tissue, SNB (CS1-CS5), GoGn (CS1-CS5), ArGoNa (CS1-CS5), ArGo (CS1-CS2) and SNA (CS1-CS2) in mouth breathing children and adolescents were below the standard values (P < 0.05). NGoMe (CS1-CS5), SN-MP (CS1-CS4), SN-PP (CS1-CS4), PP-MP (CS1-CS3) and SN-GoGn (CS1-CS2) in mouth breathing children and adolescents were above the standard values (P < 0.05). As for maxillofacial soft tissue measurements, H angle (CS1-CS5), lower lip length (CS1-CS5), upper lip protrusion (CS1-CS5), upper lip length (CS1-CS4), lower lip protrusion (CS1-CS3), surface Angle (CS2-CS3) and nasolabial angle (CS2) in mouth breathing children and adolescents were above the standard values with statistically significance (P < 0.05). As for airway measurements, PAS (CS1, CS2, CS5) in mouth breathing children and adolescents was above the standard value with statistical significance (P < 0.05). CONCLUSIONS: Mouth breathing had a real effect on maxillofacial and airway development, which differed among mouth breathing children and adolescents with different cervical vertebral maturation.

Three-Dimensional Analysis of Alveolar Bone Morphological Characteristics in Skeletal Class II Open Bite Malocclusion: A Cone-Beam Computed Tomography Study.

This cross-sectional research evaluated the morphological characteristics of alveolar bone in skeletal class II open-bite individuals compared to skeletal class II and class I non-open-bite individuals. A sample of 82 patients (all were in cervical vertebral stage 6) was divided into three groups (class II OB group, n = 29; class II NOB group, n = 29; class I NOB group, n = 24) according to bilateral molar relationship, ANB angle, and anterior overbite measured by cephalometric analysis. The evaluation was performed with specialized software (Mimics 21.0) and initial cone-beam computed tomography (CBCT) data. The alveolar bone height and thickness of the whole dentition area and alveolar crest level and root apex position of the incisors were measured with a series of appropriate CBCT images. One-way analysis of variance followed by the Tukey post hoc test and the Kruskall−Wallis test were performed for statistical comparisons. The class II open-bite group had increased alveolar bone height for the maxillary first molar and decreased alveolar bone height for mandibular molars compared to the class II non-open-bite group (p < 0.05 for both). Furthermore, there were significant negative correlations between the alveolar bone heights of the upper first and second molars (A6-height, A7-height) and overbite (both p < 0.01). The alveolar thicknesses of all measured teeth were generally reduced in the class II OB group.