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 Common Retention Practices Among Orthodontists from Different Countries.

Objective: To investigate the most common retention practices, factors influencing the retention protocol, and the differences among orthodontists regarding retention practices. Methods: An online validated questionnaire was anonymously sent to 3,000 orthodontic residents and clinicians. The survey consisted of 19 questions regarding the participants' demographics, prescribed retention appliances, factors affecting retention appliance choices, and adjunctive retention procedures. Descriptive statistics, Chi2 and Kendall's Tau-b tests were applied. Results: Five hundred fifty-five orthodontic residents and clinicians, 53.3% males and 46.7% females, completed the survey, indicating a response rate of 18.5%. Although participants' demographics, type of treatment and pre-treatment malocclusion influence the choice of retention protocols, thermoplastic retainers (TR) were the most popular retention regime for the maxillary arch for both adults (47.4%) and adolescents (42.3%). Bonded retainers (BR) were the favored option for the mandibular arch (44.9% of adults and 40.7% of adolescents). The degree of arch expansion (64.1%) and the degree of interdigitation (50.1%) after treatment were the most influential factors for the choice of the preferred type of retainers by the respondents. 68.6% of the participants thought professional retention guidelines would be useful. Conclusion: Thermoplastic retainers were the most common retention appliances for adults and adolescents in the maxilla. At the same time, BR was the most favored retainer in the mandibular arch, with clinical experience, practice setting, and malocclusion- and treatment-related factors influencing the type of the chosen appliance. The demographic differences and the uneven participation in the survey need to be considered while interpreting the findings of this study.

Trial sequential analysis: A simple guide for judging the conclusiveness of the effect.

Meta-analysis is a statistical method used in systematic reviews to provide a quantitative estimate of the effect. However, including very few studies and participants may increase the risk of spurious findings. Trial sequential analysis (TSA) has been introduced to enhance the robustness of meta-analysis. TSA is a cumulative meta-analysis method that weighs type I and II errors while estimating the effect. The application of TSA can lead to a more accurate estimation of the clinical effectiveness of the intervention. The aim of the present paper was to introduce the TSA to orthodontic clinicians and researchers using continuous data from an orthodontic systematic review.

Do statistical heterogeneity methods impact the results of meta- analyses? A meta epidemiological study.

BACKGROUND: Orthodontic systematic reviews (SRs) use different methods to pool the individual studies in a meta-analysis when indicated. However, the number of studies included in orthodontic meta-analyses is relatively small. This study aimed to evaluate the direction of estimate changes of orthodontic meta-analyses (MAs) using different between-study variance methods considering the level of heterogeneity when few trials were pooled. METHODS: Search and study selection: Systematic reviews (SRs) published over the last three years, from the 1st of January 2020 to the 31st of December 2022, in six main orthodontic journals with at least one MA pooling five or lesser primary studies were identified. Data collection and analysis: Data were extracted from each eligible MA, which was replicated in a random effect model using DerSimonian and Laird (DL), Paule-Mandel (PM), Restricted maximum-likelihood (REML), Hartung Knapp and Sidik Jonkman (HKSJ) methods. The results were reported using median and interquartile range (IQR) for continuous data and frequencies for categorical data and analyzed using non-parametric tests. The Boruta algorithm was used to assess the significant predictors for the significant change in the confidence interval between the different methods compared to the DL method, which was only feasible using the HKSJ method. RESULTS: 146 MAs were included, most applying the random effect model (n = 111; 76%) and pooling continuous data using mean difference (n = 121; 83%). The median number of studies was three (range 2, 4), and the overall statistical heterogeneity (I2 ranged from 0 to 99% with a median of 68%). Close to 60% of the significant findings became non-significant when HKSJ was applied compared to the DL method and when the heterogeneity was present I2>0%. On the other hand, 30.43% of the non-significant meta-analyses using the DL method became significant when HKSJ was used when the heterogeneity was absent I2 = 0%. CONCLUSION: Orthodontic MAs with few studies can produce different results based on the between-study variance method and the statistical heterogeneity level. Compared to DL, HKSJ method is overconservative when I2 is greater than 0% and may result in false positive findings when the heterogeneity is absent.

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.

Insufficient information size and potentially false results in orthodontic meta-analyses using trial sequential analysis.

BACKGROUND: Meta-analysis (MA) is a common mathematical method used in systematic reviews (SRs) to gather data from different studies. MA may result in overestimation or underestimation of the effect due to systematic and random errors. Trial sequential analysis (TSA) has been used to overcome the limitations of conventional MA. The objective of this study was to re-evaluate the findings of orthodontic MAs using TSA to investigate the conclusiveness of the effect and to estimate the required information size (IS). METHODS: Orthodontic SRs with MA published between 1 January 2013 and 31 December 2022 in the leading orthodontic journals were sourced. Data from arm-level MAs were extracted and re-entered in TSA software. RESULTS: A total of 180 papers were assessed against the inclusion criteria. Finally, 50 SRs with MAs were included. TSA found that almost half of the MAs with significant results demonstrated firm evidence of effect. While 38% of the significant MAs confirmed potentially spurious evidence of effect. In contrast, only one MA with insignificant findings showed a lack of effect. Furthermore, a larger number of patients were needed when the evidence of the effect was absent. CONCLUSIONS: TSA revealed that many orthodontic MAs have potentially false-positive results and have insufficient IS.

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).

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).

Global survey to assess preferences for attending virtual orthodontic learning sessions: Pre-webinar settings.

OBJECTIVES: To assess technical factors and audience preferences before attending orthodontic online learning activity, the demand for which increased dramatically in the era of the COVID-19 pandemic. DESIGN: Cross-sectional study. SETTING: Online survey. PARTICIPANTS: Global orthodontic residents and specialists. METHODS: A validated and anonymous survey comprising 17 online questions was sent to 3000 individuals. The data were collected three months later. Descriptive statistics and non-parametric tests were applied. RESULTS: The participants' response rate was 19.9%, with almost equal gender participation. Most of the responders were based in Asia (51.4%). Almost half of the participants were aged 25-35 years with less than 5 years of clinical experience. Regardless of the age, gender or global distribution, 57.3% of respondents opted to share limited personal information with the host. One-third of the respondents preferred receiving webinar reminders via email, ideally a day and/or one hour before the webinar, especially being exportable to their calendars. Age played a major role in shaping this trend, as young participants favoured the one hour (1-h) pre-webinar reminder more than other age groups (P=0.02). Receiving information about the speaker, learning outcomes and pre-webinar reading material (WRM) were preferable, particularly among young participants in comparison with the older age groups (P<0.05). Male participants from Asia and Africa preferred to attend online lectures during the mid-evening on weekends compared with women who were in favour of early evening sessions (P<0.05). CONCLUSION: It must be borne in mind during the interpretation of the results that the data were collected during the COVID-19 pandemic. It is important to take into consideration the gender, age, cultural background and level of experience while setting up virtual orthodontic learning sessions. Organisers need to tailor their events to meet the needs of the attendees.

Is there a difference among different bonded retainers in regard to survival rate?

Design A retrospective study.Cohort selection Inclusion criteria included: participants of any age who had completed their fixed orthodontic treatment on both arches and were treated by the same orthodontist in their private practice; had bonded retainers for five years, which were placed immediately after the orthodontic treatment in both arches; had one of three types of bonded retainers (0.026 × 0.010 inch Bond-A-Braid, 0.038 × 0.016 inch Ortho-FlexTech and Reliance Retainium Superior Brand Lingual Retainer Wire); had a final overbite of 2-4 mm after the completion of orthodontic treatment. Subjects who got their retainers changed, repaired or removed before five years, and syndromic patients, were excluded from the study.Data analysis The participants who agreed to contribute to the study and came for the final clinical examination were assessed for the retention status and the periodontal/gingival indies. Retention and retainer status: unwanted tooth movements and time and type of retainer failure. Periodontal/gingival indies: maximum pocket depth (PD) from the lingual side for the retained teeth and bleeding on probing (BOP). The authors performed a series of analyses to compare the orthodontic retainers regarding several outcomes and demographic variables. Briefly, the authors compared the orthodontic retainers concerning: i) age and treatment duration using analysis of variance (since the data were found to be normally distributed based on the Kolmogorov-Smirnov test); ii) demographic variables and BOP using several Chi-square tests; iii) PD via the Kruskal-Wallis test; and iv) survival rate through a Cox regression model alongside log-rank test.Results In total, 118 patients were included in this study, of which, 90 were women and 28 were men, with an average age of 22.34 ± 6.44 years. There was no statistically significant difference in the survival rate between the three types of retainers or between men and women. Likewise, there was no statistically significant difference in survival rate between the different age groups for the maxilla and mandible. Different maximum and minimum failure rates were observed between teeth in the maxilla and the mandible in the three retainers' group.Conclusions No difference was found between the three types of bonded retainers in regard to the survival rate and periodontal indices.

Global survey to assess preferences for attending virtual orthodontic learning sessions.

INTRODUCTION: Nowadays, there is a tremendous increase in the conducting of virtual orthodontic learning sessions (VOLSs). This study aimed to investigate the fundamental technical and settings aspects of VOLSs. METHODS: Three thousand orthodontic residents and specialists worldwide were invited via e-mail to complete an anonymous survey, including 23 prevalidated questions. Reminders were sent at 2-week intervals. When the sample size was reached, the survey was locked. Descriptive and inferential statistics were performed. RESULTS: Two hundred ninety-four males and 299 females of various age groups completed the survey; 61.9% of the participants opted to view the speaker's live video and the presentation's screen concurrently. Participants favored a speaker/screen ratio of 1:6 (57.5%), e-housekeeping before VOLSs (58%), appointed moderators for each VOLS (8.31 out of 10; 95% CI: 8.13, 8.48), and a nondistractive virtual background for the speakers/moderators (21.9%). Participants supported broadcasting before the start of the lecture of the VOLS (6.7 out of 10; 95% CI: 6.50, 6.95), with this being significantly influenced by the gender of participants and their continent of residence (P <0.001). Only 17.4% opted against live streaming of the VOLSs. Muting the attendees' microphones (90.5%) and having their videos switched off (62.39%) was preferable; 49.4% used their personal computers to view the lecture, whereas 27.5% used mobile phones. A webinar of 60-90 minutes duration was preferred by 76.6% of the VOLSs participants; 53.1% of the participants opted for a questions and answers session at the end of VOLSs. CONCLUSIONS: Organizers should take into consideration the impact of the digital body language of the speaker, the role of the moderator, cultural background, and privacy concerns of the attendees while organizing VOLSs. Orthodontic clinicians prefer to spend 60-90 minutes attending an interactive online session in which they can raise their questions during and at the end of the VOLSs.

Are longitudinal randomised controlled oral health trials properly analysed? A meta-epidemiological study.

INTRODUCTION: Longitudinal designs with multiple outcome measurements are commonly encountered in oral health randomised controlled trials (RCTs). The aim of this meta epidemiological study was to assess whether optimal statistical analysis approaches have been used in longitudinal oral health RCTs. DATA SOURCES: PubMed search was undertaken in September 2021 for longitudinal oral health RCTs with at least 3 repeated outcome measurements which have been published between 2016 and 2020 in the highest impact general and specialty dental journals. STUDY SELECTION: Study selection and data extraction were accomplished independently and in duplicate. The statistical methods undertaken in the selected articles were tabulated, and the association between study characteristics and use of optimal analyses were assessed using X2 or Fisher's exact test and logistic regression. RESULTS: Five hundred and five oral health RCTs were deemed eligible for inclusion. Of these, only 28.3% RCTs used optimal statistical analyses for a longitudinal trial design. For the trials with an optimal statistical approach, the most frequent test used was repeated measures analysis of variance (RM-ANOVA) followed by mixed effect models (MEM). The use of optimal statistical tests was predicated by the involvement of a statistician (OR: 2, 95% CI:1.27-3.18, p < 0.01), the journal impact factor (OR:1.19, 95% CI;1.1-1.29), continent of first author (likelihood ratio test p = 0.01), number of the authors (OR:1.22, 95% CI;1.12-1.3, p < 0.001), protocol registration (OR: 1.48, 95%CI; 1 to 2.2, p = 0.05), funding(OR:2.4, 95%CI; 1.6-3.7, p < 0.001), and dental specialty (likelihood ratio test p < 0.001). CONCLUSIONS: Most longitudinal oral health RCTs did not use optimal statistical analyses. Greater awareness of optimal analyses used to assess longitudinal data reported in oral health trials is required to circumvent the reporting of suboptimal inferences, selective reporting and research waste. CLINICAL SIGNIFICANCE: Further progress is required to avoid suboptimal statistical analyses and fully utilise the benefits of the repeated measurements over time in oral health RCTs.

Do sample size calculations in longitudinal orthodontic trials use the advantages of this study design?

OBJECTIVES: To examine whether optimal calculations of the sample size are being used in longitudinal orthodontic trials. MATERIALS AND METHODS: Longitudinal orthodontic trials with a minimum of three time points of outcome assessment published between January 1, 2017, and December 30, 2020, were sourced from a single electronic database. Study characteristics at the level of each trial were undertaken independently and in duplicate. Descriptive statistics and summary values were calculated. Inferential statistics (Fisher's exact test and logistic regression) were applied to detect associations between reporting of a sample size calculation and the study characteristics. RESULTS: A total of 147 trials were analyzed; 75.5% of these trials reported a sample size calculation with none reporting optimal sample size calculation for longitudinal trials. Most of the longitudinal orthodontic trials did not report the correlation and the number of longitudinal measurements in calculating the sample size. An association between reporting of a sample size calculation (yes or no) and the type of journal (orthodontic and non-orthodontic) was detected with higher odds of reporting a sample size calculation in orthodontic journals than in non-orthodontic journals (3.04; 95% confidence interval, 1.4-6.59; P < .01). CONCLUSIONS: The findings of this study highlighted that the undertaking of optimal sample size calculations in longitudinal orthodontic trials is being underused. Greater awareness of the variables required for undertaking the correct sample size calculation in these trials is required to reduce suboptimal research practices.

Bracket Failure in Orthodontic Patients: The Incidence and the Influence of Different Factors.

Failure of brackets is a common problem in orthodontics. This affects the treatment time, cost, and compliance of the patient. This study was conducted to estimate the bracket failure rate and the related factors for the long term. Methodology. This ambidirectional cohort study included 150 nonsyndromic orthodontic patients undergoing fixed appliance therapy for the last two years. The same patients were followed for 7 months. Different variables related to bracket failure were evaluated. The available data were analyzed descriptively, and the Kaplan-Meier estimate was used to measure the bracket survival rate from the date of bonding to failure. Results. A total of 180 bracket bond failures in the 150 included patients (52.2% males and 47.8% females) with a median age of 17 years (range 10-25 years). 69% of brackets failures were reported within the first 6 months after bonding. About 58.3% of bracket failure was noticed in adolescent patients before the age of 18 years. The majority of the cohort (81.1%) has good oral hygiene. The failure rate in patients with normal overbite was 41.1%, in decreased overbite cases was 15%, while in deep bite cases the failure rate was 43.9% with a statistically significant difference. Adults show less bracket failure (41.7%) than adolescent patients (58.3%). More bracket failure was noted in the lower arch (55%) than the upper arch (45%), and there were more bond failures posteriorly (61%) than on the anterior teeth (39%). Majority (41.1%) of the bracket failed on round NiTi wires. Conclusion. The bracket failure rate was 6.4%, with most bracket failure occurring in the first 6 months after bonding with individual difference. There was more incidence of bond failure in an increased overbite, adolescents, lower arch, posterior teeth, and lighter alignment wires.

Do longitudinal orthodontic trials use appropriate statistical analyses? A meta-epidemiological study.

BACKGROUND: In orthodontic trials, longitudinal designs with multiple outcome measurements over time are common. The aim of this epidemiological study was to examine whether optimal statistical analysis approaches have been used in longitudinal orthodontic trials. METHODS: Pubmed was searched in August 2021 for longitudinal orthodontic trials with at least three time points of outcome assessment published in the 2017-20 period. Study selection and data extraction were done independently and in duplicate. The analysis approaches undertaken were tabulated and associations between study characteristics and the use of optimal analysis or not were assessed using Fisher's exact test and logistic regression. RESULTS: One hundred forty-seven out of 563 unique records were deemed eligible for inclusion. Only 26.50% of these trials used an optimal statistical analysis for longitudinal data where the data structure is accounted for. None of the study characteristics except the statistical significance of the results were associated with the appropriateness of the statistical analysis. The odds of significant results in studies with suboptimal analyses were higher than that in studies with optimal longitudinal analyses (odds ratio: 3.48, 95% confidence interval: 1.62, 7.46, P = 0.001). For the studies with optimal analysis, the most frequent test was repeated-measure analysis of variance (RM-ANOVA). The reporting of the statistical analysis section was suboptimal in the majority of the trials. CONCLUSION: Most longitudinal orthodontic trials are not analysed using optimal statistical approaches. Inferences and interpretation of their results are likely to be compromised.

Global survey to assess preferences when attending virtual orthodontic learning sessions: optimising uptake from virtual lectures.

OBJECTIVES: Understanding the issues concerning the conducting of virtual orthodontic learning sessions (VOLSs) is essential. This study aims to identify attendees- and host-related aspects that could optimise learning and uptake from the VOLSs. METHODOLOGY: Fourteen pre-validated questions were anonymously and electronically sent to 3000 orthodontic residents and specialists globally. The survey included demographic questions and questions to gauge attendees' engagement, memorising, and motivation-related factors. Reminders were sent at two-week intervals to non-respondents. The survey was closed when the sample size was met. Descriptive and inferential statistics were performed. RESULTS: 593 orthodontic residents and specialists (294 males and 299 females), primarily junior orthodontists and residents aged between 25 and 35 years of age, completed the survey. Post-VOLS recording was highly requested by the participants (8.84/10, 95% CI 8.67-9.00) with no significant influence of demographics on this trend (p > 0.05). Most of the participants were in favour of short post-VOLSs feedback (6.79/10 95% CI 6.58-6.99) with significant differences (p = 0.048) between participants from different regions of the world. The average number of screenshots taken was 6.1 per lecture. The learners' interests in attending on-line lectures were mainly to learn new clinical orthodontic tips (96.8%). CONCLUSION: Implementing a short feedback survey after VOLSs, the provision of recording, and the provision of certificates of attendance need to be considered.

Three-dimensional nasolabial changes after maxillary advancement osteotomy in class III individuals: a systematic review and meta-analysis.

Background Class III malocclusions with maxillary retrognathia are commonly treated with single jaw Le Fort I maxillary advancement. The three-dimensional (3D) effects of surgery on the nasolabial region varies among the clinical studies. Quantifying these changes is of great importance for surgical planning and obtaining valid consent. Objectives To investigate the 3D relationship between soft tissue and skeletal changes secondary to Le Fort I maxillary advancement surgery in skeletal class III patients.Search methods Comprehensive search of multiple electronic databases supplemented by a manual and grey literature search were undertaken from inception to 9 June 2020.Selection criteria Studies that evaluated the 3D soft tissue changes of patients before and after maxillary advancement surgery alone.Data collection and analysis Study selection, data extraction and risk of bias assessment were performed independently by two reviewers, with disputes resolved by a third reviewer. A quantitative synthesis of the data was pre-planned for pooling similar outcome measures.Results Four studies were included in the final review and meta-analysis, with a total of 105 patients (mean age 16.7 + 33.9 years). The mean maxillary advancement of the included studies was 5.58 mm (95% CI 5.20-5.96). The sagittal effects of surgery on nose tip projection and prominence were insignificant (P >0.05, two studies); however, subnasal projection (MD 1.7 mm, two studies) and upper lip projection (MD 2.90 mm, four studies) increased significantly in a forward direction after surgery (P <0.05). Le Fort I osteotomy widens the upper philtrum width (MD 0.84 mm, two studies) (P <0.05). Inconsistencies among the included studies were identified; therefore, the results should be interpreted with caution.Conclusions There is weak evidence based on quantitative assessments that Le Fort I maxillary advancement significantly affects the nasolabial soft tissue envelope mainly in a sagittal dimension. These changes are concentrated around the central zone of the nasolabial region. Future prospective studies on maxillary advancement osteotomy with a standardised method of assessment, taking into consideration the confounding factors, are required.

The Correlation between Dental Stages and Skeletal Maturity Stages.

INTRODUCTION: The determination of skeletal maturity stages is very important in orthodontic treatment planning, especially skeletal discrepancies in growing individuals. A hand-wrist radiograph is considered the most accurate approach for skeletal maturity detection. Dental calcification stages have been suggested as an alternative diagnostic method to decrease radiation exposure. The recent study is aimed at detecting the efficacy of dental calcification stages in assessing skeletal maturity during the prepubertal and pubertal growth periods. METHODS: Patients' records were collected from the Aleppo Orthodontic Center. Dental maturity stages were assessed from a panoramic radiograph using the Demirjian method, while skeletal maturity stages were determined using the Björk method. Four permanent left mandibular teeth were included (canine, 1st premolar, 2nd premolar, and 2nd molar) for the study. RESULTS: From 517 records, 295 records (145 males and 150 females) were included. The Spearman rank-order correlation coefficients between skeletal maturation and dental maturation were strong and statistically significant (ranging from 0.789 to 0.835). The highest correlation was between skeletal stages and the second molar (r = 0.829 and 0.88 in males and females, respectively). Receiver operating characteristic (ROC ) curve suggested a high validity of the sum of dental stages for the four teeth in identifying MP3= stage (sensitivity was 70%, specificity was 92.77%, and ROC area was 0.81) but not for MP3cap (sensitivity was 50.85%, specificity was 81.36%, and ROC area was 0.66). CONCLUSIONS: The correlation between the skeletal maturity stages and the dental calcification stages was high. The orthodontist can use the dental stages as a definite diagnostic tool for prepubertal growth period.