INTRODUCTION: Formative assessment with emphasis on feedback has been linked to developmental purposes of assessment, whilst summative assessment is assumed to focus on judgemental and quality assurance purposes. This dichotomy is questioned but designs to blend formative and summative assessments in constructive ways are rare in health care education.

METHODS: We have designed an assessment model blending formative and summative assessments . In the formative assessment at the end of a course, students' responses to real-life scenarios with questions demanding responses at the relational level of understanding were assessed at three levels of understanding (incorrect, descriptive, and relational) modified after the SOLO taxonomy. Students were presented with individual feedback for each response. At the summative assessment of a subsequent course, the students' new responses were assessed underpinning a final judgement of students' performance. The assessment model was justified across three student cohorts.

RESULTS: Both formative and summative assessment events of the model provided information about the levels of understanding, unique to each student. A comparison of results from the assessments demonstrated that most responses developed to a higher level of understanding. With the summative assessment it was possible to make judgements about whether or not individual students passed the pre-set standards.

CONCLUSIONS: We argue that the current assessment model presents real interdependence between formative and summative assessments and can provide information that meets the needs of students as learners, education institutes, and health care organisations. The SOLO taxonomy can be used to emphasise the importance of developing and assessing cognitive complexity.

BACKGROUND: Multivariable prediction models are used in oral health care to identify individuals with an increased likelihood of caries increment. The outcomes of the models should help to manage individualized interventions and to determine the periodicity of service. The objective was to review and critically appraise studies of multivariable prediction models of caries increment.

METHODS: Longitudinal studies that developed or validated prediction models of caries and expressed caries increment as a function of at least three predictors were included. PubMed, Cochrane Library, and Web of Science supplemented with reference lists of included studies were searched. Two reviewers independently extracted data using CHARMS (Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies) and assessed risk of bias and concern regarding applicability using PROBAST (Prediction model Risk Of Bias ASessment Tool). Predictors were analysed and model performance was recalculated as estimated positive (LR +) and negative likelihood ratios (LR -) based on sensitivity and specificity presented in the studies included.

RESULTS: Among the 765 reports identified, 21 studies providing 66 prediction models fulfilled the inclusion criteria. Over 150 candidate predictors were considered, and 31 predictors remained in studies of final developmental models: caries experience, mutans streptococci in saliva, fluoride supplements, and visible dental plaque being the most common predictors. Predictive performances varied, providing LR + and LR - ranges of 0.78-10.3 and 0.0-1.1, respectively. Only four models of coronal caries and one root caries model scored LR + values of at least 5. All studies were assessed as having high risk of bias, generally due to insufficient number of outcomes in relation to candidate predictors and considerable uncertainty regarding predictor thresholds and measurements. Concern regarding applicability was low overall.

CONCLUSIONS: The review calls attention to several methodological deficiencies and the significant heterogeneity observed across the studies ruled out meta-analyses. Flawed or distorted study estimates lead to uncertainty about the prediction, which limits the models' usefulness in clinical decision-making. The modest performance of most models implies that alternative predictors should be considered, such as bacteria with acid tolerant properties.

TRIAL REGISTRATION: PROSPERO CRD#152,467 April 28, 2020.

OBJECTIVES: To apply the ROBIS tool for assessment of risk of bias (RoB) in systematic reviews (SRs) in a meta-review on effective doses (EDs) in dental and maxillofacial cone beam CT.

METHODS: Three electronic databases and reference lists of included SRs were searched. Eligible SRs were classified as having low, high or unclear RoB. Findings of SRs were synthesised and data from primary studies combined to relate ED to field of view (FOV) and operating potential (kV).

RESULTS: Seven SRs were included: three displayed low RoB, three high and one had unclear RoB. Only one SR related ED to image quality. Deficiencies in reporting of eligibility criteria, study selection and synthesis of results in SRs were identified. FOV height had a significant relationship with ED, explaining 27.2% of its variability. Median ED for three FOV categories differed significantly. Operating potential had a weak relationship with ED, with no significant difference in median ED between three operating potential groups.

CONCLUSION: The ROBIS tool should have a role for meta-reviews of different aspects of radiology. The disappointing results for RoB might be remedied by developing standards to improve the quality of reporting of primary dosimetry studies and of SRs. Future dosimetry studies should always relate ED to image quality or diagnostic accuracy.

ADVANCES IN KNOWLEDGE: This meta-review is the first to implement ROBIS for SRs of ED and identified that trustworthiness of some SRs is questionable. The percentage change in average ED per cm increase in FOV height could be calculated, emphasizing the importance of FOV as a determinant of ED in CBCT.

BACKGROUND AND AIMS: Systematic reviews (SRs) are considered to provide reliable estimates, but flaws in designs, methods of monitoring effects, and outcomes have the potential to bias results. There are several tools for assessing risk of bias (RoB), most of them designed for SRs of beneficial effects. To our knowledge, there is no tool that is adapted specifically to assess RoB in studies of adverse effects associated with orthodontic treatment. To address this, the aim of this study was first to introduce a tool for assessment of RoB in studies of adverse effects associated with orthodontic treatment and, second, to apply it in an SR of external root resorption (ERR) associated with orthodontic treatment with fixed appliance.

MATERIALS AND METHODS: The approach with domains supported by signalling questions was used for the tool. Domains and signalling questions were tailored to the review questions of the SR of studies of ERR after orthodontic treatment using periapical radiography or cone beam computed tomography. Duplicate study selection, data extraction, and RoB assessment using the tool, followed by meta-analyses, were performed.

RESULTS: Using the tool for the assessment of RoB identified shortcomings and report deficiencies of primary studies concerning the presentation of orthodontic treatment, identification of ERR, and analysis of outcomes. RoB assessment resulted in 12 of 32 studies read in full text being included. Reported severe ERR varied across studies between 2 and 14 per cent for all incisors and 10 and 29 per cent for maxillary incisors. Results of ERR related to patients' age and sex, orthodontic diagnosis, and treatment were contradictory. Quality of evidence evaluated by GRADE was low due to study limitations, imprecision, and inconsistency of study results.

CONCLUSIONS: As the tool and its application highlight important issues to consider when planning, conducting, and reporting research, the tool may have a valuable role for quality enhancement of future studies of outcomes of orthodontic treatment. The tool may also serve for authors when planning SRs. Our SR identified a need for studies that use rigorous methodology and transparent reporting.

REGISTRATION: PROSPERO (ID = CRD42018084725).

Objectives: Direct cost for methods of prediction also named risk assessment in dentistry may be negligible compared with the cost of extensive constructions. On the other hand, as risk assessment is performed daily and for several patients in general dental practice, the costs may be considerable. The objective was to summarize evidence in studies of economic evaluation of prognostic prediction multivariable models and methods of caries and periodontitis and to identify knowledge gaps (PROSPERO registration number: CRD42020149763). Material and methods: Four electronic databases (PubMed, Web of Science, The Cochrane Library, NHS Economic Evaluation Database) and reference lists of included studies were searched. Titles and abstracts were screened by two reviewers in parallel. Full-text studies reporting resources used, costs and cost-effectiveness of prediction models and methods were selected and critically appraised using a protocol based on items from the CHEERS checklist for economic evaluations and the CHARMS checklist for evaluation of prediction studies. Results: From 38 selected studies, six studies on prediction fulfilled the eligibility criteria, four on caries and two on periodontitis. As the economic evaluations differed in method and perspective among the studies, the results could not be generalized. Our systematic review revealed methodological shortcomings regarding the description of predictive models and methods, and particularly of the economic evaluation. Conclusions: The systematic review highlighted a paucity of economic evaluations regarding methods or multivariable models for prediction of caries and periodontitis. Our results indicate that what we currently practice using models and methods to predict caries and periodontitis lacks evidence regarding cost-effectiveness.

The REduce research Waste And Reward Diligence statement has highlighted how weaknesses in health research can produce misleading results and waste valuable resources. Research on diagnostic efficacy in the field of dentomaxillofacial radiology (DMFR) is no exception to these criticisms and could be strengthened by more robust study designs, consistent use of a core set of outcome measures and completeness in reporting. Furthermore, we advocate that everyone participating in collaborative research on clinical interventions subscribes to the importance of methodological quality in how imaging methods are used. The aim of this paper, therefore, is to present a guide to conducting high-quality research on diagnostic efficacy in DMFR.We initially propose a framework inspired by the hierarchical model of efficacy of Fryback and Thornbury, highlighting study designs, measures of analysis, completeness of reporting and established guidelines to assist in these aspects of research. Bias in research, and measures to prevent or limit it, are then described.It is desirable to climb the Fryback and Thornbury "ladder" from technical efficacy, via accuracy and clinical efficacy, to societal efficacy of imaging methods. Efficacy studies on the higher steps of the ladder may be difficult to perform, but we must strive to answer questions of how useful our methods are in patient management and assess benefits, risks, costs, ethical and social issues. With the framework of six efficacy levels as the structure and based on our experience, we present information that may facilitate quality enhancement of diagnostic efficacy research in DMFR.

Objectives: To evaluate measurability and reliability of measurements of root length and marginal bone level in CBCT, periapical (PA) and bitewing (BW) radiographs. Methods: CBCT of both jaws, PA of maxillary incisors and posterior BW radiographs of 10 adolescents (mean age 13.4) were selected. The radiographs comprised part of the baseline examinations of a trial of orthodontic treatment. Six raters assessed measurability and measured root length and marginal bone level. Three raters repeated their assessments. Measurability was expressed as frequency of interpretable sites and reliability as intraclass correlation coefficient (ICC). Results: Measurability was 100 % in CBCT and 95 % in PA of maxillary incisors for root length measurements. For marginal bone level, measurability was 100 % in CBCT, 76 % in PA and 86 % in posterior BW. Mean ICC for interrater reliability for root length measurements in CBCT was 0.88 (range 0.27-0.96 among different teeth) and 0.69 in PA of maxillary incisors. For marginal bone level measurements, mean ICC was 0.4 in CBCT, 0.38 in PA of maxillary incisors and 0.4 in posterior BW. Intrarater reliability varied among methods, root length or marginal bone level and among raters, except for root length measurements in CBCT, which presented high reliability (above 0.8) for all raters. Conclusions: As measurability and reliability were high for root length measurements in CBCT, this may be the method of choice for scientific analyses in orthodontics. For clinical praxis, we recommend PA following the "as low as diagnostically acceptable" principle, as clinical decisions seem to be influenced only when severe root resorption occurs.

Objective: To evaluate effects of thresholds on estimates of predictive accuracy of methods for caries risk assessment. Material and methods: Adolescents, aged 12 visiting two dental clinics, were examined by visual/tactile examination and bitewing radiography at baseline and after one year. Three methods for caries risk assessment were applied: previous caries experience, dentists’ risk assessment according to set criteria (presence or absence of caries lesion) and acid tolerance of dental biofilm. The measure for validity (the reference standard) comprised caries lesion progression at 1 year. Predictive accuracy estimates were calculated for several thresholds. Results: Accuracy estimates changed with threshold values of the methods and the reference standard. Patient spectrum differed between the clinics, which resulted in different accuracy estimates for the two samples. Generally, negative predictive values were high while positive ones were low indicating that these methods were more efficient in finding individuals who are at low risk of developing caries lesions than those with increased risk. Conclusions: As thresholds and patient spectrum affected predictive accuracy, it may be difficult to design a universal model with set thresholds for caries risk assessment. Foremost, a model should consider the level of aspiration for prediction and clinical decisions that will be made based on the risk assessment in the actual clinical setting.

AIM: To compare dental students' perceptions of their learning approaches between different years of a problem-based learning (PBL) programme. The hypothesis was that in a comparison between senior and junior students, the senior students would perceive themselves as having a higher level of deep learning approach and a lower level of surface learning approach than junior students would. This hypothesis was based on the fact that senior students have longer experience of a student-centred educational context, which is supposed to underpin student learning. PARTICIPANTS AND METHODS: Students of three cohorts (first year, third year and fifth year) of a PBL-based dental programme were asked to respond to a questionnaire (R-SPQ-2F) developed to analyse students' learning approaches, that is deep approach and surface approach, using four subscales including deep strategy, surface strategy, deep motive and surface motive. The results of the three cohorts were compared using a one-way analysis of variance (ANOVA). A P-value was set at <0.05 for statistical significance. RESULTS: The fifth-year students demonstrated a lower surface approach than the first-year students (P = 0.020). There was a significant decrease in surface strategy from the first to the fifth year (P = 0.003). No differences were found concerning deep approach or its subscales (deep strategy and deep motive) between the mean scores of the three cohorts. CONCLUSIONS: The results did not show the expected increased depth in learning approaches over the programme years.

OBJECTIVES: To design and pilot a novel classification system for the assessment of caries lesion progression in bitewing radiography and to report rater agreement of the system.

METHODS: A classification system with drawings and text was designed to assess caries lesion progression. Guidelines for Reporting Reliability and Agreement Studies were used to study and report rater agreement. Pairs of posterior bitewing radiographs (baseline and 1-year follow-up) with different status concerning caries lesion progression were selected from files from public dental health clinics. 10 raters, 5 general dental practitioners and 5 specialists in oral and maxillofacial radiology were asked to assess the radiographs with the aid of the classification system. Seven raters repeated their assessments. Rater agreement was expressed as percentage of agreement and kappa.

RESULTS: Kappa for the interrater agreement of 10 raters assessing progression was 0.61, indicating substantial agreement. Agreement was moderate for progression in the outer half of the dentine (kappa 0.55) and within enamel (kappa 0.44). Pairwise interrater agreement varied (range 69-92%; kappa 0.42-0.84). For about half of the pairs of raters, kappa was substantial (≥0.61). Intrarater agreement assessing progression was substantial (kappa 0.66-0.82).

CONCLUSIONS: We demonstrated the applicability of the proposed classification system on caries lesion progression with respect to rater agreement. This system can provide a common framework for clinical decision-making on caries interventional methods and patient visiting intervals. Scientifically, this system allows for a comparative analysis of different methods of prevention and treatment of caries as well as of different caries risk assessment methods.