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ObjectivesTo evaluate the accuracy of ITK-SNAP software for measuring volumes of a non-regular shape structure, using cone beam computed tomography (CBCT) scans, besides for developing a mathematical model to correct the software measurement error in case it existed.MethodsA phantom made by moulding a rubber duck’s head was filled with total (38,000 mm3) and partial volumes of water (7000 mm3, 14,000 mm3, 21,000 mm3, 28,000 mm3 and 35,000 mm3), which constituted the gold standards. The sound phantom and the phantom filled with different volumes of water were scanned in a Picasso Trio CBCT unit set at 80 kVp, 3.7 mA, 0.2 mm3 voxel and 12 × 8.5 cm field of view. Semi-automatic segmentation was performed with ITK-SNAP 3.0 software by two trained oral radiologists. Linear regression analyzed the relation between ITK-SNAP calculated volumes and the gold standard. Intraclass correlation coefficient was applied to analyze the reproducibility of the method. Significance level was set at 5%.ResultsLinear regression analysis showed a significant relationship between ITK-SNAP volumes and the gold standard (F = 22,537.3, p < 0.0001), with an R2 of 0.9993. The average error found was 4.7 (± 4.3) %. To minimize this error, a mathematical model was developed and provided a reduction of it. ICC revealed excellent intra-examiner agreements for both examiners 1 (ICC = 0.9991, p < 0.0001) and 2 (ICC = 0.9989, p < 0.0001). Likewise, inter-examiner agreement was excellent (ICC = 0.9991, p < 0.0001).ConclusionThe software showed to be accurate for evaluating non-regular shape structures. The mathematical model developed reduced an already small error on the software’s measurements.

ObjectivesTo evaluate the influence of artifacts produced by zirconium implant on the diagnosis of vertical root fracture (VRF) in teeth close and distant to the implant in cone beam computed tomography (CBCT) images. We also determined if kilovoltage (kVp) and metal artifact reduction (MAR) tool could influence this diagnosis.Materials and methodsTwenty single-root teeth were divided in control and fractured groups (n = 10). The teeth were randomly positioned in the first and second and right and left pre-molar alveoli of a dry human mandible. CBCT exams were acquired using a ProMax 3D unit with varying kVp (70, 80, or 90 kVp), with or without MAR, and with and without a zirconium implant placed in the alveolus of first right molar. The images were evaluated by five observers. The area under the receiver operating characteristic curve (ROC), sensitivity, and specificity were calculated and compared by analysis of variance with a significance level of 5%.ResultsIn general, ROC and sensitivity were not affected by the factors studied (p > 0.05). The main effects occurred in specificity; when implant was used without MAR, the values were lower for tooth 45 for all kVps (p = 0.0001).ConclusionsArtifacts produced in the vicinity of teeth with suspected VRF impair the diagnosis by decreasing the specificity, because they can mimic the VRF line generating false positives. However, MAR improves the specificity, being its use recommended when metallic objects are present near teeth with suspected VRF.Clinical RelevanceSince nowadays, many patients who undergo CBCT show implants and they definitively produce artifacts, it is important to evaluate the influence of such artifacts in the diagnosis of teeth that are close to the generator-artifact object.

ObjectiveThe aim of this study is to evaluate the efficacy of metal artefact reduction (MAR) in different dental materials with Picasso Trio cone-beam computed tomography (CBCT) scanner.Materials and methodsThree imaging phantoms were custom-made of acrylic resin. Each phantom presented three cylinders of the same material: dental amalgam alloy, gutta-percha or aluminium-copper alloy. CBCT scans were performed on Picasso Trio unit with and without MAR, and artefact expression (standard deviation of grey values) was obtained and compared by Kruskal-Wallis and Student-Newman-Keuls (post hoc) (α = 0.05).ResultsSignificant reduction of artefact expression (p < 0.05) was observed with MAR on areas around dental alloys. No significant difference (p > 0.05) was observed with or without MAR when gutta-percha was scanned.ConclusionMAR was effective in reducing artefacts arising from dental alloys on CBCT images.Clinical relevanceDental materials of high atomic number and density are widely used in dentistry and can produce artefact that compromise CBCT image. The present study demonstrated that metal artefact reduction algorithm is an effective tool to improve image quality.

ObjectivesThe aims of this study are to identify the most frequent technical errors in endodontically treated teeth and to determine which root canals were most often associated with those errors, as well as to relate endodontic technical errors and the presence of coronal restorations with periapical status by means of cone-beam computed tomography images.MethodsSix hundred eighteen endodontically treated teeth (1146 root canals) were evaluated for the quality of their endodontic treatment and for the presence of coronal restorations and periapical lesions. Each root canal was classified according to dental groups, and the endodontic technical errors were recorded. Chi-square’s test and descriptive analyses were performed.ResultsSix hundred eighty root canals (59.3%) had periapical lesions. Maxillary molars and anterior teeth showed higher prevalence of periapical lesions (p < 0.05). Endodontic treatment quality and coronal restoration were associated with periapical status (p < 0.05). Underfilling was the most frequent technical error in all root canals, except for the second mesiobuccal root canal of maxillary molars and the distobuccal root canal of mandibular molars, which were non-filled in 78.4 and 30% of the cases, respectively.ConclusionsThere is a high prevalence of apical radiolucencies, which increased in the presence of poor coronal restorations, endodontic technical errors, and when both conditions were concomitant. Underfilling was the most frequent technical error, followed by non-homogeneous and non-filled canals.Clinical relevanceEvaluation of endodontic treatment quality that considers every single root canal aims on warning dental practitioners of the prevalence of technical errors that could be avoided with careful treatment planning and execution.

Background As the hard palate is a central structure of the skull, and its close relationship with the nasal cavity, oral cavity, and maxillary sinuses, it would be of interest to study if there is a relationship between this bone and other structures of the stomatognathic system. Thus, this study aimed to assess the dimensions of the hard palate and associate them with sex, and skeletal and breathing patterns. Also, to investigate if there is a relationship between these dimensions and the volumes of the upper airways and maxillary sinuses. Methods Two hundred and ninety-eight CBCT scans of patients were classified according to sex, and skeletal and breathing patterns. Then, the linear dimensions of width and height of the hard palate at the regions of the first premolars and first molars, and the volumes of the upper airways and maxillary sinuses were measured using the CS 3D Imaging and ITK-SNAP software, respectively. Data were submitted to multi-way analysis of variance and linear regression, with a significance level of 5% (α = 0.05). Results Sex and facial type influenced the hard palate dimensions ( p  < 0.05). Males had greater width and height of the hard palate than females ( p  < 0.0001). It was observed greater width for brachycephalics at the first premolars region ( p  = 0.0032), and greater height for dolichocephalics at the first premolars ( p  = 0.0154) and first molars ( p  = 0.0038) regions. Skeletal malocclusion and breathing pattern did not influence the measurements of the hard palate ( p  > 0.05). There was a significant relationship between the width and height of the hard palate at the premolar’s region and the total volume of the upper airways ( p  = 0.018, and p  = 0.038), and between both dimensions of the hard palate at the molar’s region and the total volume of the maxillary sinuses ( p  < 0.0001). Conclusions The hard palate dimensions are influenced by sex and facial type, but not by skeletal malocclusion or breathing pattern. Also, there is an association between these dimensions and the volumes of the upper airways and maxillary sinuses.

Objective To assess the performance of cephalometric landmark identification performed by two AI-driven software programs in images from different populations (Brazilian and Korean). Methods Sixty lateral cephalometric radiographs (30 Brazilian and 30 Korean) were analyzed. The Brazilian images were acquired using the Orthophos XG 5/Ceph device, while the Korean images were obtained from the International Symposium on Biomedical Imaging 2015 database. Images of patients with permanent dentition were included, excluding those with poor head positioning or severe craniofacial deformities. Twenty cephalometric landmarks were identified by two examiners used as the reference standard. Two AI-driven software programs, CefBot™ (Brazil) and WebCeph™ (Korea), automatically identified the same landmarks. Coordinate values for each landmark were measured using ImageJ, and the data were analyzed with Analysis of Variance and Dunnett’s post-hoc test. Results The Brazilian software showed high accuracy in identifying landmarks on Brazilian images (90%) but was less precise on Korean images (80%), with significant discrepancies in the Glabella, Menton L, Basion, and Orbitale landmarks. Similarly, the Korean software had a higher accuracy in its own population (95%) than in another population (85%), with notable inaccuracies in the Menton L, Basion, and Porion landmarks. Conclusion Discrepancies in the identification of specific landmarks, such as Glabella and Menton L, suggest that the accuracy of the software may be influenced by the training process itself and by the population origin of the training data.

Background Since the muscles of chewing are involved in the region of the mandibular angle, important structures in surgical and orthodontic procedures, to study its morphological aspects and the possible influence of different patterns of skeletal development would be of interest. Thus, this study aimed to assess the influence of patient characteristics - such as sex, skeletal malocclusion (Class I, Class II, and Class III) and facial type (brachycephalic, mesocephalic, and dolichocephalic) - on the width, height, thickness, and volume of the mandibular angle, using cone-beam computed tomography (CBCT) scans. Methods CBCT scans were assessed − 144 men and 154 women, total of 298 - and classified according to skeletal patterns (skeletal malocclusions and facial types). Width, height, and thickness of the mandibular angle were measured using OnDemand 3D software. The volumetric measures of the mandibular angle were obtained using the ITK-SNAP software. Analysis of Variance (multiway ANOVA) with Tukey’s post-hoc test compared the data, with a 5% significance level. Results Among the factors studied, sex significantly influenced all the analyzed variables (height, width, thickness, and volume of the mandibular angle) (p < 0.05); in general, male individuals presented higher values than females. In some cases, the skeletal malocclusion and facial type factors influenced only the width and height variables (p < 0.05); in general, the Class III and dolichocephalic individuals presented higher values in relation to the other types of skeletal malocclusions and facial types. Conclusions Variations in the craniofacial growth pattern, considering the different skeletal malocclusions and facial types, had some influence in the width and height dimensions of the mandibular angle. Furthermore, sex influenced all the studied variables.

IntroductionThe aim of this study was to report the first case of diagnosis of a rare ethmoid sinolith by cone-beam computed tomography (CBCT) and discuss the importance of carefully assessing the entire volume of the images regardless of the region of interest.Case presentationA 22-year-old woman underwent CBCT examination to assess the upper permanent canine teeth. Analysis of the entire volume of CBCT revealed an oval-shaped hyperdense, homogeneous, expansive formation with defined boundaries located in the ethmoid bone. The differential diagnosis of a sinolith in the ethmoid sinus was confirmed after removal of the lesion by nasoendoscopy and histopathological examination.ConclusionThe diagnosis of lesions in the ethmoid sinus is challenging because of the complex anatomy of this region. Considering the limitations of two-dimensional X-ray examination, CBCT examination has become an important imaging modality for the diagnosis of these calcifications. In addition, the ability of the dental surgeon to assess the entire volume of the CBCT images and the knowledge of imaging features of these calcifications allows for recognition of incidental findings, facilitating early diagnosis and appropriate treatment.

ObjectivesTo evaluate the performance of periapical radiography assessed under different radiographic brightness and contrast variations in the detection of simulated internal (IRR) and external (ERR) root resorption lesions. Additionally, observers’ preferences related to image quality for these diagnostic tasks were evaluated.MethodsThirty single-root teeth were divided into two groups (n = 15): IRR, in which lesions were simulated using mechanical and biochemical processes; and ERR, in which cavities standardized with drills of different sizes were performed on the root surfaces. Digital radiographs were obtained and subsequently adjusted in 4 additional combinations, resulting in 5 brightness/contrast variations (V1–V5). Five radiologists evaluated the radiographs. The observers’ preference on the image quality was also recorded.ResultsFor both conditions, there were no differences in the accuracy and specificity between the five brightness/contrast variations (p > 0.05), but the sensitivity for ERR was significantly lower in V4 (+ 15% brightness/−15% contrast) in the large size (p < 0.05). The observers classified V2 (− 15% brightness/+15% contrast) as the “best” image quality for IRR and ERR evaluation.ConclusionsFor IRR and ERR lesions, brightness and contrast variation does not affect the diagnostic performance of digital intraoral radiography within the tested range. The observers prefer images with a reasonable decrease in brightness and increase in contrast.Clinical relevanceBrightness and contrast enhancement tools are commonly applied in digital radiographic assessment. The use of these tools for detection of root resorptions can be applied according to the observer preference without influence on diagnostic accuracy.

Purpose: The objective of this study was to evaluate perception and feelings experienced by dentistry professors and students about distance learning during the COVID-19 pandemic. Materials and Methods: Fifty professors and fifty-two students reported the perceptions and implications of distance learning imposed by the pandemic of COVID-19. The participants' answers were analyzed using the qualitative-quantitative method of the collective subject's discourse. The answers were summarized in central ideas, distributed in absolute and relative frequency. The answers with similar central ideas were grouped, obtaining the discourse of the collective subject. Results: The similar central ideas about distance learning addressed by professors and students were: suitable for didactic courses; limited laboratory and clinical courses, and internet access difficulties. Specifically for professors: a complement to classroom teaching; stress and learning with digital technologies; difficulty in reconciling classes with domestic activities; concerns with motivation and interaction with students; asynchronous lectures favor knowledge fixation, and synchronous lectures favor interaction with students; unreliable assessment methods; concern about returning to face-to-face classes. For the students: it was applied to all courses; demotivating; fundamental to guide studies; professors' commitment; long lectures; excessive school activities; difficult attendance control and evaluation; the comfort of being at home; impact on research. Conclusion: Professors considered distance learning as a learning opportunity on how to use digital technologies but too limited for lab and clinical activities and interaction with students. Students found it discouraging due to the absence of practical classes and excessive school activities.