Heloísa Emília Dias da Silveira

Reproducibility of Cephalometric Measurements Made by Three Radiology Clinics

The purpose of this study was to assess reproducibility of cephalometric measurements in cephalograms obtained by three dentomaxillofacial radiology clinics. Forty lateral cephalometric radiographs were selected and sent at different times to three different clinics for cephalometric analyses. Each clinic digitized the radiographs with the same resolution, and landmarks were located with the mouse pointer directly on the digitized radiographic image on the screen. Three cephalograms were obtained from each radiograph, totaling 120 analyses. Data were analyzed with analysis of variance. Of the 32 factors studied, reproducibility of results was satisfactory for only four factors: position of maxilla relative to anterior cranial base, inclination of occlusal plane relative to anterior cranial base, position of lower incisor relative to nasion-pogonion line, and soft-tissue profile of face (P < .05). Differences in cephalometric measurements were present and such differences were significant for most factors analyzed. The different cephalometric measurements obtained by the three dental radiology clinics were not reproducible.

Software system for calibrating examiners in cephalometric point identification.

INTRODUCTIONnThe literature has shown that subjective concepts lead to interobserver variations in the definitions and identifications of cephalometric landmarks. Observers must be trained and calibrated to conduct scientific research using cephalometric comparisons. In this study, we aimed to develop and test a computational model called Cyclops cephalometry in radiographic cephalometry training and calibration.nnnMETHODSnThis system uses the concepts of evaluation process managers, examiners, and testers, thus affording uniformity in cephalometric evaluations. The system was tested with 5 orthodontists and 5 postgraduate students who located 28 landmarks in 10 lateral cephalometric radiographs before and after training.nnnRESULTSnBefore training, the Student t test showed significant differences (P <0.05) in accuracy between the orthodontists and the students (71.4% and 54.9%, respectively). However, considerable improvement in accuracy was observed after training in both groups (86.5% and 83%, respectively), without significant differences (P = 0.30) between groups. Users of the system agreed about its usability aspects such as effectiveness, efficiency, and satisfaction.nnnCONCLUSIONSnThis model was shown to be a useful and efficient tool in the calibration process, and might be helpful in various comparative cephalometric investigations.

Imaging evaluating of the implant/bone interface—an in vitro radiographic study

OBJECTIVESnTo analyze the diagnostic accuracy of conventional and digital radiographic images and the impact of digital filters in evaluating the bone-implant interface.nnnMETHODSnTitanium implants were inserted into 74 fresh bovine ribs blocks, 37 fitting tight to the bone walls (simulating the existence of osseointegration) and 37 with a gap of 0.125u2009mm (simulating a failure in the osseointegration process). Periapical radiographs were taken with conventional film and two phosphor plate systems [VistaScan® (Dürr Dental, Bietigheim-Bissingen, Germany) and Express® (Instrumentarium, Tuusula, Finland)]. Digital radiographs were investigated with and without enhancement filters. Three blinded examiners assessed the images for the presence of juxtaposition in the bone-implant interface using a five-point Likert scale. Sensitivity, specificity and the area under the receiver-operating characteristic curve (AUC) and its 95% confidence interval (CI) were calculated for each variable. Intraexaminer and interexaminer agreements were analyzed using Kendalls concordance test.nnnRESULTSnIntraexaminer and interexaminer agreements were >0.80 for both digital and conventional images. Conventional radiographs (AUCu2009=u20090.963/CIu2009=u20090.891 to 0.993) and digital images with high enhancement filters such as Caries2 (AUCu2009=u20090.964/CIu2009=u20090.892 to 0.993), Endo (AUCu2009=u20090.952/CIu2009=u20090.875 to 0.988) and Sharpen3 (AUCu2009=u20090.894/CIu2009=u20090.801 to 0.954) showed the greatest accuracy for evaluating the bone-implant interface. Original images from both digital systems and the further enhancement filters tested showed low sensitivity for the diagnosis task tested.nnnCONCLUSIONSnConventional radiographs or digital radiographs with high-pass filters could help enhance diagnosis on implant-bone interface.

Teaching Dental Students to Understand the Temporomandibular Joint Using MRI: Comparison of Conventional and Digital Learning Methods

The aims of this study were to evaluate and compare the performance of dental students in interpreting the temporomandibular joint (TMJ) with magnetic resonance imaging (MRI) scans using two learning methods (conventional and digital interactive learning) and to examine the usability of the digital learning object (DLO). The DLO consisted of tutorials about MRI and anatomic and functional aspects of the TMJ. In 2014, dental students in their final year of study who were enrolled in the elective MRI Interpretation of the TMJ course comprised the study sample. After exclusions for nonattendance and other reasons, 29 of the initial 37 students participated in the study, for a participation rate of 78%. The participants were divided into two groups: a digital interactive learning group (n=14) and a conventional learning group (n=15). Both methods were assessed by an objective test applied before and after training and classes. Aspects such as support and training requirements, complexity, and consistency of the DLO were also evaluated using the System Usability Scale (SUS). A significant between-group difference in the posttest results was found, with the conventional learning group scoring better than the DLO group, indicated by mean scores of 9.20 and 8.11, respectively, out of 10. However, when the pretest and posttest results were compared, both groups showed significantly improved performance. The SUS score was 89, which represented a high acceptance of the DLO by the users. The students who used the conventional method of learning showed superior performance in interpreting the TMJ using MRI compared to the group that used digital interactive learning.

Detection of vertical root fractures: an investigation on the impact of using orthogonal and dissociated radiographs in conventional and digital systems

Introduction: Intraoral radiographs are an important investigative aid in the detection of endodontic injuries, including vertical root fractures (VRF). Objective: The objective of this study was to assess the capacity of orthogonal and angulated conventional as well as digital radiographs to detect VRF in teeth under different root conditions. Methods: Sixty teeth were divided into three groups according to the canal condition: non-filled, filled with gutta-percha and filled with gutta-percha and metallic post. Ten teeth in each group were artificially fractured, whereas teeth in the control group were not fractured. Orthogonal and horizontally angulated conventional film (Kodak) and digital phosphor plate (VistaScan Durr Dental) were used. Three blinded and calibrated observers carried out evaluations at four different time intervals. Modal values were used to calculate sensibility, specificity and accuracy. The area under the ROC curve (aucROC) and confidence intervals (CI) was used to compare the performance between radiographic systems, as well as the influence of combined angulated images. Results: Angulated radiographs showed larger aucROC for both conventional and digital images. CI revealed statistically significant differences between conventional orthogonal and digital angulated radiographs (CI: 0.403 – 0.697 and 0.767 – 0.967, respectively). Moreover, when only orthogonal incidences were considered, digital radiographs yielded better results than the conventional ones (CI: 0.403 – 0.697 and 0.622 – 0.878, respectively). Conclusion: The strong inclination towards yielding better diagnostic test results provided by digital radiographs suggests that the digital system using angulated projections is more appropriate to investigate VRF than the conventional one.