Reporting of Research Quality Characteristics of Studies Published in 6 Major Clinical Dental Specialty Journals

A scoping review of early childhood caries, poverty and the first sustainable development goal

BACKGROUND

Poverty is a well-known risk factor for poor health. This scoping review (ScR) mapped research linking early childhood caries (ECC) and poverty using the targets and indicators of the Sustainable Development Goal 1 (SDG1).

METHODS

We searched PubMed, Web of Science, and Scopus in December 2023 using search terms derived from SDG1. Studies were included if they addressed clinically assessed or reported ECC, used indicators of monetary or multidimensional poverty or both, and were published in English with no date restriction. We excluded books and studies where data of children under 6 years of age could not be extracted. We charted the publication year, study location (categorized into income levels and continents), children age, sample size, study design, measures of ECC, types and levels of poverty indicators and adjusted analysis. The publications were also classified based on how the relation between poverty and ECC was conceptualized.

RESULTS

In total, 193 publications were included with 3.4 million children. The studies were published from 1989 to 2023. Europe and North America produced the highest number of publications, predominantly from the UK and the US, respectively. Age-wise, 3-5-year-olds were the most studied (62.2%). Primary studies (83.9%) were the majority, primarily of cross-sectional design (69.8%). Non-primary studies (16.1%) included reviews and systematic reviews. ECC was mainly measured using the dmf indices (79.3%), while poverty indicators varied, with the most common used indicator being income (46.1%). Most studies measured poverty at family (48.7%) and individual (30.1%) levels. The greatest percentage of publications addressed poverty as an exposure or confounder (53.4%), with some studies using poverty to describe groups (11.9%) or report policies or programs addressing ECC in disadvantaged communities (11.4%). In addition, 24.1% of studies requiring adjusted analysis lacked it. Only 13% of publications aligned with SDG1 indicators and targets.

CONCLUSION

The ScR highlight the need for studies to use indicators that provide a comprehensive understanding of poverty and thoroughly examine the social, political, and economic determinants and impact of ECC. More studies in low and middle-income countries and country-level studies may help design interventions that are setting- and economic context-relevant.

The Oral Health Statistics Guidelines for Reporting Observational Studies and Clinical Trials in Oral Health Research: Explanation and Elaboration

Adequate and transparent reporting is necessary for critically appraising research. Yet, evidence suggests that the design, conduct, analysis, interpretation, and reporting of oral health research could be greatly improved. Accordingly, the Task Force on Design and Analysis in Oral Health Research-statisticians and trialists from academia and industry-empaneled a group of authors to develop methodological and statistical reporting guidelines identifying the minimum information needed to document and evaluate observational studies and clinical trials in oral health: the Oral Health Statistics Guidelines. Drafts were circulated to the editors of 85 oral health journals and to task force members and sponsors and discussed at a December 2020 workshop attended by 49 researchers. The final version was subsequently approved by the task force in September 2021, submitted for journal review in 2022, and revised in 2023. The checklist consists of 48 guidelines: 5 for introductory information, 17 for methods, 13 for statistical analysis, 6 for results, and 7 for interpretation; 7 are specific to clinical trials. Each of these guidelines identifies relevant information, explains its importance, and often describes best practices. The checklist was published in multiple journals. The article was published simultaneously in Journal of Dental Research Clinical and Translational Research, the Journal of the American Dental Association, and the Journal of Oral and Maxillofacial Surgery. Completed checklists should accompany manuscripts submitted for publication to these and other oral health journals to help authors, journal editors, and reviewers verify that the manuscript provides the information necessary to adequately document and evaluate the research.

The OHStat Guidelines for Reporting Observational Studies and Clinical Trials in Oral Health Research: explanation and elaboration

Adequate and transparent reporting is necessary for critically appraising research. Yet, evidence suggests that the design, conduct, analysis, interpretation, and reporting of oral health research could be greatly improved. Accordingly, the Task Force on Design and Analysis in Oral Health Research-statisticians and trialists from academia and industry-empaneled a group of authors to develop methodological and statistical reporting guidelines identifying the minimum information needed to document and evaluate observational studies and clinical trials in oral health: the OHstat Guidelines. Drafts were circulated to the editors of 85 oral health journals and to Task Force members and sponsors and discussed at a December 2020 workshop attended by 49 researchers. The final version was subsequently approved by the Task Force in September 2021, submitted for journal review in 2022, and revised in 2023. The checklist consists of 48 guidelines: 5 for introductory information, 17 for methods, 13 for statistical analysis, 6 for results, and 7 for interpretation; 7 are specific to clinical trials. Each of these guidelines identifies relevant information, explains its importance, and often describes best practices. The checklist was published in multiple journals. The article was published simultaneously in JDR Clinical and Translational Research, the Journal of the American Dental Association, and the Journal of Oral and Maxillofacial Surgery. Completed checklists should accompany manuscripts submitted for publication to these and other oral health journals to help authors, journal editors, and reviewers verify that the manuscript provides the information necessary to adequately document and evaluate the research.

The OHStat Guidelines for Reporting Observational Studies and Clinical Trials in Oral Health Research: Explanation and Elaboration

Adequate and transparent reporting is necessary for critically appraising research. Yet, evidence suggests that the design, conduct, analysis, interpretation, and reporting of oral health research could be greatly improved. Accordingly, the Task Force on Design and Analysis in Oral Health Research-statisticians and trialists from academia and industry-empaneled a group of authors to develop methodological and statistical reporting guidelines identifying the minimum information needed to document and evaluate observational studies and clinical trials in oral health: the OHstat Guidelines. Drafts were circulated to the editors of 85 oral health journals and to Task Force members and sponsors and discussed at a December 2020 workshop attended by 49 researchers. The final version was subsequently approved by the Task Force in September 2021, submitted for journal review in 2022, and revised in 2023. The checklist consists of 48 guidelines: 5 for introductory information, 17 for methods, 13 for statistical analysis, 6 for results, and 7 for interpretation; 7 are specific to clinical trials. Each of these guidelines identifies relevant information, explains its importance, and often describes best practices. The checklist was published in multiple journals. The article was published simultaneously in JDR Clinical and Translational Research, the Journal of the American Dental Association, and the Journal of Oral and Maxillofacial Surgery. Completed checklists should accompany manuscripts submitted for publication to these and other oral health journals to help authors, journal editors, and reviewers verify that the manuscript provides the information necessary to adequately document and evaluate the research.

Quality of Reporting Randomized Controlled Trials Published in Three of the Most Citable Periodontal Journals from 2018 to 2022

This study aimed to evaluate the reporting quality of randomized clinical trials (RCTs) in periodontology. Three leading periodontology journals, the Journal of Periodontology (JOP), the Journal of Clinical Periodontology (JOCP), and the Journal of Periodontal Research (JOPR), were selected for this investigation. The RCTs were identified by manually searching for human trial articles published in these three journals. Two authors independently conducted the literature search, and a pre-piloted extraction sheet was used to screen the potential RCTs. The CONSORT checklist guidelines were employed to calculate the score value. Intra-examiner reliability was assessed by scoring a random sample of 10% of the papers in a second round conducted by the first examiner three months after the initial data collection. A search of abstracts published over a five-year period yielded 176 articles that reported RCTs, accounting for 11.7% of all articles published in the three journals. The highest number of RCTs was published in 2020, and more than half of the included RCTs (51%) originated from Europe. Many of the analyzed RCTs inadequately reported almost half of the items on the CONSORT checklist. Furthermore, univariate analysis revealed significant associations between certain factors and the overall CONSORT score, such as publication in JOP (p = 0.048), publication year of 2019 (p = 0.041) and 2021 (p = 0.042), first author from North America (p = 0.016), and RCTs with more than six authors (p = 0.042). Clinical trial research in periodontics has made significant progress in the past five years. However, there is room for improvement in adhering to the CONSORT guidelines.

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- 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.

Apriori sample size estimation and reporting in original articles published from 2012 to 2020 in two Asian orthodontic journals

AIMS:

To evaluate the proportion and completeness of reporting apriori sample size estimation (SSE) in research articles published in the Journal of Orthodontic Science (JOS) and the Journal of Indian Orthodontic Society (JIOS).

MATERIALS AND METHODS:

All online research articles published in both journals from 2012 to 2020 were screened. Those reporting apriori SSE were analyzed for the study design and completeness of SSE reporting (outcome parameter and assumptions, Type I error, Power/type II error, one or two-tailed test, the method used, justifications for assumptions, adjustments in sample size, and the target sample size). Chi-square or Fisher exact test was used to analyze the differences between the journals in the proportions of articles reporting these characteristics.

RESULTS:

Twenty articles (13.2%) in JOS and 24 (8.3%) in JIOS, have reported apriori SSE [χ² (1, N = 440) = 2.573, P=0.10]. Non-clinical and quasi-experimental studies formed nearly two-thirds of articles reporting SSE in JOS. Quasi-experimental (34%), randomized controlled trials (28%), and cross-sectional studies (24%) formed the bulk of articles reporting SSE in JIOS. Type II error/power was the most frequently reported characteristic in both (75% and 95.8% in JOS and JIOS, respectively), and the number of tails was the least (5% and 0%, respectively). More articles in JOS than JIOS reported the outcome variable used [65% vs. 12.5%, χ² (1, N = 44) = 12.99, P <.001] and provided justifications for the assumptions [70% vs 33.3%, χ² (1, N = 44) = 5.86, P = 0.01].

CONCLUSION:

The extent and completeness of reporting apriori SSE are suboptimal in these journals and require prompt and stringent curative measures.

Bioactive toothpastes in dentin hypersensitivity treatment: A systematic review

The use of bioactive materials is a recent proposal in the treatment of dentin hypersensitivity (DH) due to the ability to stimulate the neoformation of a barrier on dentin surface. Questions have arisen about the effectiveness of the materials to reduce DH when compared to the control groups (placebo or non-bioactive substance). Thus, the aim of this systematic review was to evaluate the randomized controlled trials in adult patients for DH treatment with a dentifrice containing bioactive glass, applied either at-home or in-office. Methods: The study was registered in PROSPERO and followed PRISMA guidelines. Searches were carried out in four databases (Pubmed/Medline, CENTRAL, Wbb of Science, LILACS) spanning from February 2020 to March 2020, with no language or publication date restrictions. A supplementary hand-search was performed by checking the list of references. The so-called gray literature of the national and international databases for theses and dissertations, as well as unfinished, in progress and unpublished studies were also searched. Results: After reading the titles and abstracts, articles that were duplicated (74 records) or unrelated to the systematic review (76 records) were excluded. Fifteen studies were evaluated considering seven at low risk of bias, four at high risk and four at moderate risk. Conclusion: The bioactive compounds at low concentrations (2.5–7.5%) can be used as treatment of DH both at-home and in-office.

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.

Are treatment effect assumptions in orthodontic studies overoptimistic?

Background

At the clinical trial design stage, assumptions regarding the treatment effects to be detected should be appropriate so that the required sample size can be calculated. There is evidence in the medical literature that sample size assumption can be overoptimistic. The aim of this study was to compare the distribution of the assumed effects versus that of the observed effects as a proxy for overoptimistic treatment effect assumptions at the study design stage.

Materials and method

Systematic reviews (SRs) published between 1 January 2010 and 31 December 2019 containing at least one meta-analysis on continuous outcomes were identified electronically. SR and primary study level characteristics were extracted from the SRs and the individual trials. Details on the sample size calculation process and assumptions and the observed treatment effects were extracted.

Results

Eighty-five SRs with meta-analysis containing 347 primary trials were included. The median number of SR authors was 5 (interquartile range: 4–7). At the primary study level, the majority were single centre (78.1%), utilized a parallel design (52%), and rated as an unclear/moderate level of risk of bias (34.3%). A sample size was described in only 31.7% (110/347) of studies. From this cohort of 110 studies, in only 37 studies was the assumed clinical difference that the study was designed to detect reported (37/110). The assumed treatment effect was recalculated for the remaining 73 studies (73/110). The one-sided exact signed rank test showed a significant difference between the assumed and observed treatment effects (P < 0.001) suggesting greater values for the assumed effect sizes.

Conclusions

Careful consideration of the assumptions at the design stage of orthodontic studies are necessary in order to reduce the unreliability of clinical study results and research waste.

Dental Research Waste in Design, Analysis, and Reporting: A Scoping Review

Research waste is highly prevalent across biomedical investigations. We aimed to assess the evidence on the extent of research waste in dental research. We performed a scoping review of empirical evaluations of dental studies assessing the prevalence and impact of limitations in design, conduct, analysis, and reporting of research. PubMed was searched using specific terms to retrieve studies dealing with design, conduct, analysis, and reporting of studies in dentistry, with no year or language restrictions. Of the 1,807 publications identified from the search and from manual searches, 71 were included in this review. The topic and article selection was based on the expert opinion of the authors. The existing evidence suggests that, although there are improvements over time, substantial deficiencies in all areas (design, conduct, analysis, reporting) were prevalent in dental research publications. Waste in research is a multifaceted problem without a simple solution. However, an appreciation of optimal research design and execution is a prerequisite and should be underpinned by policies that include appropriate training in research methods and properly aligned incentives.

Methods, transparency and reporting of clinical trials in orthodontics and periodontics

OBJECTIVE

The aim of this study was to explore the methods, reporting and transparency of clinical trials in orthodontics and compare them to the field of periodontics, as a standard within dentistry.

DESIGN/SETTING

Cross-sectional bibliographic study.

METHODS

A total of 300 trials published in 2017-2018 and evenly distributed in orthodontics and periodontics were selected, assessed and analysed statistically to explore key aspects of the conduct and reporting of orthodontic clinical trials compared to trials in periodontics.

RESULTS

Several aspects are often neglected in orthodontic and periodontic trials and could be improved upon, including use of statistical expertise (22.3% of assessed trials), blinding of outcome assessors (62.3%), prospective trial registration (12.0%), adequate sample size calculation (35.7%), adherence to CONSORT (14.3%) and open data sharing (4.3%). The prevalence of statistically significant findings among orthodontic and periodontic trials was 62.3%, which was significantly associated with several methodological traits like statistician involvement (odds ratio [OR] = 0.5; 95% confidence interval [CI] = 0.3-0.9), blind outcome assessor (OR = 0.5; 95% CI = 0.2-1.0), lack of prospective trial registration (OR = 2.8; 95% CI = 1.3-5.9) and non-adherence to CONSORT (OR = 4.5; 95% CI = 1.3-15.8).

CONCLUSIONS

Although trials in orthodontics seem to be significantly worse compared to periodontics in aspects like trial registration, adherence to CONSORT and declaration of competing interests or financial support, their methods do seem to have improved considerably in recent years.

Evaluating the statistical methodology of randomized trials on dentin hypersensitivity management

The present study aimed to evaluate the characteristics and quality of statistical methodology used in clinical studies on dentin hypersensitivity management. An electronic search was performed for data published from 2009 to 2014 by using PubMed, Ovid/MEDLINE, and Cochrane Library databases. The primary search terms were used in combination. Eligibility criteria included randomized clinical trials that evaluated the efficacy of desensitizing agents in terms of reducing dentin hypersensitivity. A total of 40 studies were considered eligible for assessment of quality statistical methodology. The four main concerns identified were i) use of nonparametric tests in the presence of large samples, coupled with lack of information about normality and equality of variances of the response; ii) lack of P-value adjustment for multiple comparisons; iii) failure to account for interactions between treatment and follow-up time; and iv) no information about the number of teeth examined per patient and the consequent lack of cluster-specific approach in data analysis. Owing to these concerns, statistical methodology was judged as inappropriate in 77.1% of the 35 studies that used parametric methods. Additional studies with appropriate statistical analysis are required to obtain appropriate assessment of the efficacy of desensitizing agents.

Ethical Conducts of Professors, Undergraduates and Graduate Students: The View of Dental School Patients

Introducción: la importancia atribuida a la práctica y al consentimiento informado varía entre los profesionales de salud. Esto es aun más influenciado por el entorno laboral, nivel de conocimiento, experiencia, valores y creencias sociales. El artículo tiene como fin evaluar las conductas éticas de profesores y estudiantes del pregrado y postgrado por medio de cuestionarios con pacientes. Métodos: 120 pacientes de clínicas odontológicas de tres diferentes facultades del departamento de São Paulo fueron entrevistados con preguntas discursivas y objetivas acerca de la firma del consentimiento informado, participación en investigación científica, fotos durante el tratamiento, solicitud de muestra de saliva, solicitud de donación de diente e información sobre el destino de este luego de removido. Para el análisis estadístico de los datos, se utilizó distribución de frecuencia (absoluta y porcentual). Resultados: el 65,8% de los pacientes firmó el consentimiento para tratamiento y el 12,5% no lo firmó. El 10,8% desconoce si ha participado de investigación científica. El 54,2% ha sido fotografiado durante los procedimientos odontológicos y, de ellos, el 47,1% firmó un término de autorización. A un 6,6% se les solicitó saliva y el 66,6% de ellos firmó una autorización. El 16,1% recibió una solicitud de donación de los dientes y, de ellos, el 64,4% firmó una autorización. El 61,3% desconocía el destino del diente luego de su remoción cuando la donación les fue solicitada. Conclusiones: La mayoría de los pacientes firmó el consentimiento para tratamiento, fotografías, muestra de saliva y donación de dientes. Ello demuestra qué conductas éticas ante a los pacientes se están siguiendo por los profesores y estudiantes de pre y postgrado.

Structural color changes in permanent enamel of patients with cleft lip and palate: a case-control study

OBJECTIVES

White spots are more common in patients with cleft lip and palate (CLP) than in the normal population. Whether these are due to the cleft itself or concomitant circumstances (e.g., surgical procedures, orthodontic treatments, systemic fluoridation, increased caries risk) remains unclear. This case-control study evaluated both their prevalence in CLP patients versus control subjects and associated risk factors.

PATIENTS AND METHODS

A total of 73 CLP patients (average age 8.7 years, range 6-18 years, 42 % male) and a control group of 73 age- and gender-matched non-CLP patients were included. Enamel color changes, subsuming mineralization defects (DDE index), mild dental fluorosis (Dean's index), and initial caries (ICDAS score 2), were recorded. Caries index (dmf-t/DMF-T) scores were also recorded to distinguish between high or low caries risk as defined by the Deutsche Arbeitsgemeinschaft für Jugendzahnpflege criteria. Histories of systemic fluoridation, trauma to primary teeth, surgery, and orthodontic treatment were obtained using a questionnaire. Statistical analysis included t test, χ (2) test, and multivariable logistic regression.

RESULTS

Enamel color changes were observed three times more often in the CLP group than in the control group (39.7 vs. 12.3 %; p < 0.001). Significantly more patients in the CLP group had a history of orthodontic treatment (38.4 vs. 15.1 %; p < 0.05). An increased risk for enamel color changes was associated with CLP itself [OR (odds ratio) 3.6; 95 % confidence interval (CI) 1.3-9.9] and table salt plus tablets combined for systemic fluoridation (OR 2.7, 95 % CI 1.1-6.9). No increased risks were identified for increased caries risk, history of primary-tooth trauma, or history of orthodontic treatment.

CONCLUSION

The higher prevalence of enamel color changes in the CLP group (more than threefold compared to the control group) was not related to previous orthodontic treatments; however, systemic fluoridation (table salt and tablets) constituted a risk factor for the enamel color changes seen in the CLP patients.

Reporting of clinical trials in the orthodontic literature from 2008 to 2012: observational study of published reports in four major journals

OBJECTIVE

The aim of this study is to provide an update as to whether authors in the orthodontic field of research currently report randomized clinical trials (RCTs) adequately as defined by the Consolidated Standards of Reporting Trials (CONSORT) statement.

METHODS

The American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO), Journal of Orthodontics (JO), European Journal of Orthodontics (EJO) and Angle Orthodontist (AO) were reviewed to identify all articles that reported RCTs published between January 2008 and June 2012.Reports were scored using the CONSORT 37 item checklist. A 10% random sample of the papers was scored by a second examiner to assess inter-examiner reliability of the CONSORT score. Another 10% random sample of the papers was scored a second time by the first examiner 3 months after initial data collection to test intra-examiner reliability.

RESULTS

A total of 151 clinical trial reports have been identified out of 3335 articles in the four journals from January 2008 to June 2012.Mean CONSORT score of the four journals was 51.7%. Journal of Orthodontics achieved the highest score of 73.6% and the lowest score was achieved by AO with a score of 44.5%. Overall compliance with CONSORT increased from 47.8 to 56.3% between 2008 and 2012.

CONCLUSION

Clinical trials reports represented < 5% of articles in the four main orthodontic journals between 2008 and 2012. • CONSORT mean score ranged from 44.5 to 73.6% between journals. • CONSORT mean score increased through the period of investigation.

Methodological characteristics and treatment effect sizes in oral health randomised controlled trials: Is there a relationship? Protocol for a meta-epidemiological study

INTRODUCTION

It is fundamental that randomised controlled trials (RCTs) are properly conducted in order to reach well-supported conclusions. However, there is emerging evidence that RCTs are subject to biases which can overestimate or underestimate the true treatment effect, due to flaws in the study design characteristics of such trials. The extent to which this holds true in oral health RCTs, which have some unique design characteristics compared to RCTs in other health fields, is unclear. As such, we aim to examine the empirical evidence quantifying the extent of bias associated with methodological and non-methodological characteristics in oral health RCTs.

METHODS AND ANALYSIS

We plan to perform a meta-epidemiological study, where a sample size of 60 meta-analyses (MAs) including approximately 600 RCTs will be selected. The MAs will be randomly obtained from the Oral Health Database of Systematic Reviews using a random number table; and will be considered for inclusion if they include a minimum of five RCTs, and examine a therapeutic intervention related to one of the recognised dental specialties. RCTs identified in selected MAs will be subsequently included if their study design includes a comparison between an intervention group and a placebo group or another intervention group. Data will be extracted from selected trials included in MAs based on a number of methodological and non-methodological characteristics. Moreover, the risk of bias will be assessed using the Cochrane Risk of Bias tool. Effect size estimates and measures of variability for the main outcome will be extracted from each RCT included in selected MAs, and a two-level analysis will be conducted using a meta-meta-analytic approach with a random effects model to allow for intra-MA and inter-MA heterogeneity.

ETHICS AND DISSEMINATION

The intended audiences of the findings will include dental clinicians, oral health researchers, policymakers and graduate students. The aforementioned will be introduced to the findings through workshops, seminars, round table discussions and targeted individual meetings. Other opportunities for knowledge transfer will be pursued such as key dental conferences. Finally, the results will be published as a scientific report in a dental peer-reviewed journal.

Are sample sizes clear and justified in RCTs published in dental journals?

Sample size calculations are advocated by the CONSORT group to justify sample sizes in randomized controlled trials (RCTs). The aim of this study was primarily to evaluate the reporting of sample size calculations, to establish the accuracy of these calculations in dental RCTs and to explore potential predictors associated with adequate reporting. Electronic searching was undertaken in eight leading specific and general dental journals. Replication of sample size calculations was undertaken where possible. Assumed variances or odds for control and intervention groups were also compared against those observed. The relationship between parameters including journal type, number of authors, trial design, involvement of methodologist, single-/multi-center study and region and year of publication, and the accuracy of sample size reporting was assessed using univariable and multivariable logistic regression. Of 413 RCTs identified, sufficient information to allow replication of sample size calculations was provided in only 121 studies (29.3%). Recalculations demonstrated an overall median overestimation of sample size of 15.2% after provisions for losses to follow-up. There was evidence that journal, methodologist involvement (OR = 1.97, CI: 1.10, 3.53), multi-center settings (OR = 1.86, CI: 1.01, 3.43) and time since publication (OR = 1.24, CI: 1.12, 1.38) were significant predictors of adequate description of sample size assumptions. Among journals JCP had the highest odds of adequately reporting sufficient data to permit sample size recalculation, followed by AJODO and JDR, with 61% (OR = 0.39, CI: 0.19, 0.80) and 66% (OR = 0.34, CI: 0.15, 0.75) lower odds, respectively. Both assumed variances and odds were found to underestimate the observed values. Presentation of sample size calculations in the dental literature is suboptimal; incorrect assumptions may have a bearing on the power of RCTs.

The 100 top-cited articles in orthodontics from 1975 to 2011

OBJECTIVE

To identify the 100 top-cited articles published in orthodontics journals and to analyze their characteristics to investigate the achievement and development of orthodontics research in past decades.

METHODS AND MATERIALS

The Institute for Scientific Information Web of Knowledge Database and the 2011 Journal Citation Report Science Editions were used to retrieve the 100 top-cited articles published in orthodontics journals since 1975. Some basic information was collected by the Analyze Tool on the Web of Science, including citation time, publication title, journal name, publication year, and country and institution of origin. A further study was then performed to determine authorship, article type, field of study, study design, and level of evidence.

RESULTS

The 100 target articles were retrieved from three journals: American Journal of Orthodontics and Dentofacial Orthopedics (n  =  74), The Angle Orthodontist (n = 15), and European Journal of Orthodontics (n  =  11). Since 1975, the articles cited 89 to 545 times mainly originated from the United States, and the overwhelming majority of articles were clinical. The most common study design was case series; 40 articles were classified as level IV and 12 as level V evidence.

CONCLUSIONS

The 100 top-cited articles in orthodontics are generally old articles, rarely possessing high-level evidence.