Commentary: Challenges and Opportunities for Women in Dental Research.

This commentary integrates and expands on the preceding articles in this issue that document and celebrate a century of women's achievements in the International Association for Dental Research (IADR). The increasing participation and leadership of women in dental and craniofacial research and within the IADR were viewed from the perspective of a changing culture of science. The steps that have been taken by the IADR to develop greater inclusiveness are acknowledged, and some of the challenges that remain are discussed in terms of obstacles that are most often social or cultural in origin. Comparisons are made across countries, and the social determinants that lead to differences in women's participation are described. Recommendations are made for developing strategies to change elements of our institutional cultures that have provided advantages to some groups of researchers more than to others. The unconscious biases and a lack of commitment to diversity, equity, and inclusion that limit the participation of members of some groups limit the progress and achievements of science in general.

Evaluation of dental trials comparing baseline differences using p values.

INTRODUCTION: Significance testing for comparison of the baseline differences between the intervention arms has received a strong condemnation. The goal of this study was to assess the prevalence of randomized controlled trials (RCTs) comparing the baseline characteristics between intervention groups using significance tests in top ten impact factor dental journals. MATERIALS AND METHODS: RCTs published in 10 high impact factor dental journals were searched in PubMed database. Literature search was limited to time duration of 5 years from September 2012 to August 2017. RESULTS: We analysed 521 RCTs after excluding 47 non-RCT articles from the total of 568 articles. Baseline demographic characteristics table was not reported in 45.9% of the RCTs and 26.2% of the RCTs did not report table of baseline clinical characteristics. In 38.9% of the studies, significance testing was employed to compare baseline differences between the intervention arms. CONCLUSIONS: Many trials published in the reputed dental journals failed to follow the recommendations of CONSORT statement regarding reporting of baseline tables and avoiding comparison of baseline differences with significance test.

Statistical testing against baseline in orthodontic research: a meta-epidemiologic study.

BACKGROUND/OBJECTIVES: To assess the prevalence of within-group comparisons from baseline to follow-up in published orthodontic articles and to identify potential associations between this statistical problem and a number of study characteristics. MATERIALS/METHOD: The most recent 24 issues of four leading orthodontic journals with highest impact factor (American Journal of Orthodontics and Dentofacial Orthopedics; AJODO, European Journal of Orthodontics; EJO, Angle Orthodontist; ANGLE, Orthodontics and Craniofacial Research; OCR) were electronically searched until December 31st 2017. The proportion of articles using comparisons against baseline and interpretation of findings according to within-group comparisons were recorded. The association of this practice with journal, year of publication, study design, continent of authorship, number of centres and researchers, statistical significance of results, and statistical analysis was tested. Univariable and multivariable modified Poisson regression were used to identify significant predictors. RESULTS: Overall, 339 articles were eligible for inclusion with the majority published in ANGLE (n = 157, 46%), followed by AJODO (n = 75, 22%), and EJO (n = 75, 22%). A total of 60 studies (18%) presented interpretation of their findings based on within-group comparisons against baseline in isolation. Statistical significance of the primary outcome was a very strong predictor of the prevalence of this flawed approach (RR: 2.33, 95% CIs: 1.22, 4.43; P = 0.01). LIMITATIONS: The effect of time since publication was not addressed. CONCLUSIONS/IMPLICATIONS: Statistical testing and interpretation within groups is prevalent in orthodontic research. Endorsement of accurate conduct and reporting of statistical analyses and interpretation of research findings is important in order to promote optimal inferences to support clinical decision-making.

Quality Assessment of Randomized Clinical Trials Reporting in Endodontic Journals: An Observational Study from 2012 to 2017.

INTRODUCTION: Reports on randomized clinical trials (RCTs) are of critical importance because readers of research often do not access the full text. This study aimed to assess the reporting quality of RCTs in 2 leading endodontic journals. METHODS: Issues of 2 endodontic journals, the Journal of Endodontics and the International Journal of Endodontics, dated from 2012 to 2017 were hand searched to identify RCT reports. A 37-item checklist based on the Consolidated Standards of Reporting Trials statement was used to examine the completeness of RCT reporting. RESULTS: One hundred nine RCT reports were included in this study. The majority were published in the Journal of Endodontics (82%). The mean overall reporting quality score was 65.0% (95% confidence interval, 77.3-66.5). Most (80%-100%) RCTs clearly reported the author/contact details, trial design, participant characteristics, number of participants, and recruitment status as well as the study's intervention(s), objective(s), outcome(s), and conclusions. Conversely, only 56 of the 109 articles (51%) satisfactorily reported all 5 items related to the randomization method. Registration of reviews was not reported in any of the included abstracts. Most of the studies included in this analysis did not report their RCT registration (22%), funding (35%), or protocols (23%). CONCLUSIONS: The results of this study suggest that the reporting quality of RCTs in endodontic journals requires further improvement. Better reporting of RCTs is particularly important for ensuring the reliability of research findings and ultimately promoting the practice of evidence-based dentistry. Optimal RCT reporting should be encouraged, preferably by complying with the Consolidated Standards of Reporting Trials guidelines.

Methodological and Reporting Quality of Systematic Reviews and Meta-analyses in Endodontics.

INTRODUCTION: The aim of this systematic review (SR) was to evaluate the quality of SRs and meta-analyses (MAs) in endodontics. METHODS: A comprehensive literature search was conducted to identify relevant articles in the electronic databases from January 2000 to June 2017. Two reviewers independently assessed the articles for eligibility and data extraction. SRs and MAs on interventional studies with a minimum of 2 therapeutic strategies in endodontics were included in this SR. Methodologic and reporting quality were assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) and Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), respectively. The interobserver reliability was calculated using the Cohen kappa statistic. Statistical analysis with the level of significance at P < .05 was performed using Kruskal-Wallis tests and simple linear regression analysis. RESULTS: A total of 30 articles were selected for the current SR. Using AMSTAR, the item related to the scientific quality of studies used in conclusion was adhered by less than 40% of studies. Using PRISMA, 3 items were reported by less than 40% of studies, which were on objectives, protocol registration, and funding. No association was evident comparing the number of authors and country with quality. Statistical significance was observed when quality was compared among journals, with studies published as Cochrane reviews superior to those published in other journals. AMSTAR and PRISMA scores were significantly related. CONCLUSIONS: SRs in endodontics showed variability in both methodologic and reporting quality.

Nyvad Criteria for Caries Lesion Activity and Severity Assessment: A Validated Approach for Clinical Management and Research.

The Nyvad classification is a visual-tactile caries classification system devised to enable the detection of the activity and severity of caries lesions with special focus on low-caries populations. The criteria behind the classification reflect the entire continuum of caries, ranging from clinically sound surfaces through noncavitated and microcavitated caries lesions in enamel, to frank cavitation into the dentin. Lesion activity at each severity stage is discriminated by differences in surface topography and lesion texture. The reliability of the Nyvad criteria is high to excellent when used by trained examiners in the primary and permanent dentitions. The Nyvad criteria have construct validity for lesion activity assessments because of their ability to reflect the well-known caries-controlling effect of fluoride. Predictive validity was demonstrated by showing that active noncavitated lesions are at higher risk of progressing to a cavity or filled state than do inactive noncavitated lesions. Lesion activity assessment performed successfully as a screening tool to identify individuals with a poor caries prognosis. Because of their predictive validity, the Nyvad criteria are superior to other current caries lesion descriptors for the detection of changes in the lesion activity status over time. The Nyvad criteria fulfill all the formal requirements for a robust caries lesion classification and are recommended for evidence-based caries management in clinical practice and in research.

Impact of Selection Bias on Treatment Effect Size Estimates in Randomized Trials of Oral Health Interventions: A Meta-epidemiological Study.

Emerging evidence suggests that design flaws of randomized controlled trials can result in over- or underestimation of the treatment effect size (ES). The objective of this study was to examine associations between treatment ES estimates and adequacy of sequence generation, allocation concealment, and baseline comparability among a sample of oral health randomized controlled trials. For our analysis, we selected all meta-analyses that included a minimum of 5 oral health randomized controlled trials and used continuous outcomes. We extracted data, in duplicate, related to items of selection bias (sequence generation, allocation concealment, and baseline comparability) in the Cochrane Risk of Bias tool. Using a 2-level meta-meta-analytic approach with a random effects model to allow for intra- and inter-meta-analysis heterogeneity, we quantified the impact of selection bias on the magnitude of ES estimates. We identified 64 meta-analyses, including 540 randomized controlled trials analyzing 137,957 patients. Sequence generation was judged to be adequate (at low risk of bias) in 32% ( n = 173) of trials, and baseline comparability was judged to be adequate in 77.8% of trials. Allocation concealment was unclear in the majority of trials ( n = 458, 84.8%). We identified significantly larger treatment ES estimates in trials that had inadequate/unknown sequence generation (difference in ES = 0.13; 95% CI: 0.01 to 0.25) and inadequate/unknown allocation concealment (difference in ES = 0.15; 95% CI: 0.02 to 0.27). In contrast, baseline imbalance (difference in ES = 0.01, 95% CI: -0.09 to 0.12) was not associated with inflated or underestimated ES. In conclusion, treatment ES estimates were 0.13 and 0.15 larger in trials with inadequate/unknown sequence generation and inadequate/unknown allocation concealment, respectively. Therefore, authors of systematic reviews using oral health randomized controlled trials should perform sensitivity analyses based on the adequacy of sequence generation and allocation concealment.

The use of tailored subheadings was successful in enhancing compliance with CONSORT in a dental journal.

OBJECTIVES: Efforts to enhance the reporting of clinical trials have intensified in recent years with automated strategies and editorial involvement showing promise in improving compliance with accepted guidelines. This study aimed to evaluate the effectiveness of a concerted approach to adherence to CONSORT (CONsolidated Standards Of Reporting Trials) guidelines in a dental journal. MATERIALS AND METHODS: Following the publication of an exemplar clinical trial on the American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO) website and related changes to the author guidelines, trial submissions were required to follow a standard format incorporating subheadings mirroring the CONSORT guidelines. Compliance with CONSORT was assessed in initial submissions over a 30-month period. Reporting was compared to submissions of randomized controlled trials (RCTs) which did not include subheadings over the same period. RESULTS: Seventy-one RCTs were submitted to the AJO-DO from January 2014 to June 2016, 49 with subheadings and 22 without. Most CONSORT items (e.g. random sequence generation, allocation concealment and blinding) were more frequently adequately reported when RCTs were submitted with inclusion of subheadings. Overall, reporting quality of the submitted RCTs was 15.2% higher with use of the subheadings format (95%CI: 10.5, 20.0; p<0.001) with a mean overall score of 87.3%. CONCLUSION: Enhanced compliance of submitted RCTs was found with use of a bespoke approach to trial presentation utilizing CONSORT item subheadings. The improvement in initial submissions is particularly encouraging as this arose without input either from peer reviewers or journal editors. This simple approach may have wider applicability.

Expert panels as a reference standard in orthodontic research: An assessment of published methods and reporting.

INTRODUCTION: The aim of this study was to investigate the expert panel methodology applied in orthodontics and its reporting quality. Additionally, the relationship between the reporting quality and a range of variables was explored. METHODS: PubMed was searched for orthodontic studies in which the final diagnosis or assessment was made by 2 or more experts published up to March 16, 2015. Reporting quality assessment was conducted using an established modified checklist. The relationship between potential predictors and the total score was assessed using univariable linear regression. RESULTS: We identified 237 studies with a mean score of 9.97 (SD, 1.12) out of a maximum of 15. Critical information about panel methodology was missing in all studies. The panel composition differed substantially across studies, ranging from 2 to 646 panel members, with large variations in the expertise represented. Only 17 studies (7.2%) reported sample size calculations to justify the panel size. Panel members were partly blinded in 65 (27.4%) studies. Most studies failed to report which statistic was used to compute intrarater (65.8%) and interrater (66.2%) agreements. Journal type (nonorthodontic: ß, 0.23; 95% CI, -0.07 to 0.54 compared with orthodontic), publication year (ß, 0; 95% CI, -0.02 to 0.02 for each additional year), number of authors (1-3: ß, 0.30; 95% CI, -0.13 to 0.74 compared with at least 6; 4-5: ß, 0.18; 95% CI, -0.29 to 0.33 compared with at least 6), and number of centers involved (single: ß, 0.20; 95% CI, -0.14 to 0.54 compared with multicenter) were not significant predictors of improved reporting. Studies published in Asia and Australia had significantly lower scores compared with those published in Europe (ß, -0.54; 95% CI, -0.92 to -0.17). CONCLUSIONS: Formal guidelines on methodology and reporting of studies involving expert panels are required.

Surveys on Reporting Guideline Usage in Dental Journals.

The objectives of this study were 1) to find out if and how authors and peer reviewers for dental journals are encouraged to use reporting guidelines (RGs); 2) to identify factors related to RG endorsement; and 3) to assess the knowledge, opinions, and future plans of dental journal editors in chief (EICs) on RGs. A total of 109 peer-reviewed and original research-oriented dental journals that were indexed in the MEDLINE and/or SCIE database in 2015 were included. The "instructions to authors" and "instructions to reviewers" of these journals were identified and retrieved from journals' official websites. Any mention of RGs or other related policies were sought and extracted. In addition, an anonymous survey of the EICs of the included journals was conducted with a validated questionnaire. All 109 journals provided "instructions to authors," among which 55 (50.5%) mentioned RGs. Only the CONSORT (45.0%), PRISMA (13.8%), and STROBE (12.8%) guidelines were mentioned by >10% of the included journals. Statistical analyses suggest that RGs were more frequently mentioned by SCIE-indexed journals (P < 0.001), higher-impact journals (P = 0.002), and journals that endorsed the ICMJE recommendations (P < 0.001). "Instructions to reviewers" were available online for only 9 journals (8.3%), 3 of which mentioned RGs. For the EIC survey, the response rate was 32.1% (35 of 109). Twenty-six editors (74.3%) stated that they knew what RGs were before receiving our questionnaire. Twenty-four editors (68.6%) believed that RGs should be adopted by all refereed dental journals where appropriate. RGs are important tools for enhancing research reporting and reducing avoidable research waste, but currently they are not widely endorsed by dental journals. Joint efforts by all stakeholders to further promote RG usage in dentistry are needed.

Research Waste: How Are Dental Survival Articles Indexed and Reported?

PURPOSE: Research waste occurs when research is ignored, cannot be found, cannot be used, or is unintentionally repeated. This article aims to investigate how dental survival analyses were indexed and reported, and to discuss whether errors in indexing and writing articles are affecting identification and use of survival articles, contributing to research waste. MATERIALS AND METHODS: Articles reporting survival of dental prostheses in humans (also known as time-to-event) were identified by searching 50 dental journals that had the highest Impact Factor in 2008. These journals were hand searched twice (Kappa 0.92), and the articles were assessed by two independent reviewers (Kappa 0.86) to identify dental survival articles ("case" articles, n = 95), likely false positives (active controls, n = 91), and all other true negative articles (passive controls, n = 6,769). This means that the study used a case:control method. Once identified, the different groups of articles were assessed and compared. Allocation of medical subject headings (MeSH) by MEDLINE indexers that related to survival was sought, use of words by authors in the abstract and title that related to survival was identified, and use of words and figures by authors that related to survival in the articles themselves was also sought. Differences were assessed with chi-square and Fisher's Exact statistics. Reporting quality was also assessed. The results were reviewed to discuss their potential impact on research waste. RESULTS: Allocation of survival-related MeSH index terms across the three article groups was inconsistent and inaccurate. Statistical MeSH had not been allocated to 30% of the dental survival "case" articles and had been incorrectly allocated to 15% of active controls. Additionally, information reported by authors in titles and abstracts varied, with only two-thirds of survival "case" articles mentioning survival "statistics" in the abstract. In the articles themselves, time-to-event statistical methods, survival curves, and life tables were poorly reported or constructed. Overall, the low quality of indexing by indexers and reporting by authors means that these articles will not be readily identifiable through electronic searches, and, even if they are found, the poor reporting quality makes it unnecessarily difficult for readers to understand and use them. CONCLUSION: There are substantial problems with the reporting of time-to-event analyses in the dental literature. These problems will adversely impact how these articles can be found and used, thereby contributing to research waste. Changes are needed in the way that authors report these studies and the way indexers classify them.

Statistical analysis in orthodontic journals: are we ignoring confounding?

AIM: To assess the prevalence of adjustment for confounding within statistical analysis and matching at the design stage in leading orthodontic journals and to explore potential associations between accounting for confounding and publication characteristics. MATERIALS AND METHODS: Twenty-four issues of four leading orthodontic journals with the highest impact factor were searched from July 2014 backwards. Confounding adjustment through statistical analysis and study characteristics including journal, study design, region of origin, number of authors, number of centres, involvement of a statistician, significance of results, and type of analysis were recorded. Reporting of matching at the design stage was also recorded. RESULTS: Of 426 studies identified, only 71 (17 per cent) accounted for confounding in the statistical analysis. There was evidence that journal, country of authorship, and involvement of a statistician (odds ratio = 3.91, 95 per cent confidence interval: 2.16-7.10; P < 0.001) were significant predictors of accounting for confounding at the analysis level. Reporting of matching at the design stage was identified in 111 of 426 (26 per cent) studies in which 9 studies adjusted for confounding at the analysis level. CONCLUSIONS: Appropriate adjustment for confounding in orthodontic literature either at the design or at the analysis stage was identified in less than half of studies overall (41 per cent), suggesting lack of expertise and awareness in design, conduct, analysis, and reporting of non-randomized studies in this field. This is a critical limitation that can potentially result in biased estimates and associations between examined exposures and outcomes.

An Assessment of the Risk of Bias in Randomized Controlled Trial Reports Published in Prosthodontic and Implant Dentistry Journals.

PURPOSE: The objective of this study was to assess the risk of bias of randomized controlled trials (RCTs) published in prosthodontic and implant dentistry journals. MATERIALS AND METHODS: The last 30 issues of 9 journals in the field of prosthodontic and implant dentistry (Clinical Implant Dentistry and Related Research, Clinical Oral Implants Research, Implant Dentistry, International Journal of Oral & Maxillofacial Implants, International Journal of Periodontics and Restorative Dentistry, International Journal of Prosthodontics, Journal of Dentistry, Journal of Oral Rehabilitation, and Journal of Prosthetic Dentistry) were hand-searched for RCTs. Risk of bias was assessed using the Cochrane Collaboration's risk of bias tool and analyzed descriptively. RESULTS: From the 3,667 articles screened, a total of 147 RCTs were identified and included. The number of published RCTs increased with time. The overall distribution of a high risk of bias assessment varied across the domains of the Cochrane risk of bias tool: 8% for random sequence generation, 18% for allocation concealment, 41% for masking, 47% for blinding of outcome assessment, 7% for incomplete outcome data, 12% for selective reporting, and 41% for other biases. CONCLUSION: The distribution of high risk of bias for RCTs published in the selected prosthodontic and implant dentistry journals varied among journals and ranged from 8% to 47%, which can be considered as substantial.

What is the Proper Sample Size for Studies of Periodontal Treatment?

Small sample sizes are a common problem in biomedical research, and the periodontal literature is no exception. It is a problem leading to not only reduced statistical power but also an inappropriate statistical inference of a treatment effect. Using statistical methods with an insufficient sample size may give rise to an increased chance of falsely detecting treatment efficacy. This article provides some guidelines to cope with the small sample size problem. The authors discuss adequate sample sizes in several statistical tests and then suggest alternative statistical methods that are valid with a small sample size.