Data important when estimating effective dose were insufficiently reported in most studies. A model with minimum data based on this observation is proposed. Few studies related effective dose to image quality.

For a dedicated CBCT unit, changing the rotation angle from 360° to 180° degrades image quality. By altering tube potential and current for the 360° rotation protocol, assessment of periodontal structures can be performed with a smaller dose without substantially affecting visualization.

Objectives: To demonstrate the feasibility of GafChromic ® XR-QA2 (ISP Corp., Wayne, NJ) as a dosemeter when performing measurements of the effective dose from three cone beam CT (CBCT) units and to compare the doses from examinations of three common dental clinical situations. A second aim was to compare the radiation doses for three digital panoramic units with the doses for the CBCT units. Methods: The CBCT units used were Veraviewepocs 3De ® (J Morita MFG Corp., Kyoto, Japan), ProMax ® 3D (Planmeca, Helsinki, Finland) and NewTom VGi ® (Quantitative Radiology, Verona, Italy). GafChromic XR-QA2 films were placed between the selected layers of the head and neck of a tissue-equivalent human skull (RANDO ® phantom; The Phantom Laboratory, Salem, NY). The exposure parameters were set using the automatic exposure control function of the units. Depending on the availability, medium and smaller field of view (FOV) scanning modes were used. The effective dose was estimated using the 2007 International Commission on Radiological Protection formalism. Results: The lowest effective dose of a CBCT unit was observed for ProMax 3D, FOV 4 3 5 cm (10 mSv), the highest for NewTom VGi, FOV 8 3 8 cm-high resolution (129 mSv). The range of effective doses for digital panoramic machines measured was 8-14 mSv. Conclusions: This study demonstrates the feasibility of using radiochromic films for dental CBCT and panoramic dosimetry.

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.

Objectives: The purpose of this study was to evaluate rater agreement and the accuracy of a semi-automated software and its fully automated tool for osteoporosis risk assessment in intraoral radiographs. Methods: A total of 567 intraoral radiographs was selected retrospectively from women aged 75–80 years participating in a large population-based study (SUPERB) based in Gothenburg, Sweden. Five raters assessed participants’ risk of osteoporosis in the intraoral radiographs using a semi-automated software. Assessments were repeated after 4 weeks on 121 radiographs (20%) randomly selected from the original 567. Radiographs were also assessed by the softwares’ fully automated tool for analysis. Results: Overall interrater agreement for the five raters was 0.37 (95% CI 0.32–0.41), and for the five raters with the fully automated tool included as ‘sixth rater’ the overall Kappa was 0.34 (0.30–0.38). Intrarater agreement varied from moderate to substantial according to the Landis and Koch interpretation scale. Diagnostic accuracy was calculated in relation to reference standard for osteoporosis diagnosis which is T-score values for spine, total hip and femoral neck and presented in form of sensitivities, specificities, predictive values, likelihood ratios and odds ratios. All raters' mean sensitivity, including the fully automated tool, was 40,4% (range 14,3%–57,6%). Corresponding values for specificity was 69,5% (range 59,7%–90,4%). The diagnostic odds ratios ranged between 1 and 2.7. Conclusion: The low diagnostic odds ratio and agreement between raters in osteoporosis risk assessment using the software for analysis of the trabecular pattern in intraoral radiographs shows that more work needs to be done to optimise the automation of trabecular pattern analysis in intraoral radiographs.

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. Median ED for three FOV categories differed significantly (p < 0.001) but there was 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. There is a continuing need to perform dosimetry studies, although relating ED to image quality or diagnostic accuracy would add value. Advances in knowledge: This meta-review is the first in radiology to implement ROBIS to assess RoB in SRs of ED and identified that the trustworthiness of some SRs is questionable. The results underpin the importance of FOV dimensions as a determinant of ED in CBCT.

Objectives To investigate rater agreement regarding measurements of height and width of the maxilla and mandible using cross-sectional images from CBCT examinations. Furthermore, to explore the association between vertical craniofacial height and alveolar bone morphology. Methods Pre-treatment CBCT scans from 450 patients referred for treatment to a private clinic for orthodontics and oral surgery in Scandinavia were available and of these, 180 were selected. Lateral head images were generated from the CBCT volumes to categorise subjects into three groups based on their craniofacial height. Cross-sectional images of the maxillary and mandibular bodies at three locations in the maxilla and mandible, respectively, were obtained and measured at one height and two width recordings by five raters. One-way analysis of variance with a Tukey post hoc test was performed. A significance level of 5% was used. Results Rater agreement was mostly excellent or good when measuring height and width of the maxilla and mandible in cross-sectional CBCT images. For height (of the alveolar bone/bodies), there were statistically significant differences between the low- and the high-angle groups for all the observers when measuring in the premolar and midline regions, both in the maxilla and in the mandible. Conclusion The high agreement found ensures a reliable measurement technique and confirms the relation between craniofacial height and alveolar bone height and width.

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