Impact of different evaluation methods for diagnostic tasks in panoramic radiography / Impacto de diferentes métodos de evaluación durante el diagnóstico en la radiografía panorámica

Abstract The aim of this study was to evaluate the observers diagnostic performance in panoramic radiography using monitor, tablet, X-ray image view box, and against window daylight as a visualization method in different diagnostic tasks. Thirty panoramic radiography were assessed by three calibrated observers for each visualization method, in standardized light conditions, concerning dental caries, widened periodontal ligament space, and periapical bone defects from the four first molars; mucosal thickening and retention cysts in maxillary sinus; and stylo-hyoid ligament calcification and atheroma. A five-point confidence scale was used. The standard-reference was performed by two experienced observers. Diagnostic values using window light were significantly lower for caries and periapical bone defect and retention cyst, stylo-hyoid ligament calcification detection (p<0.05). For atheroma detection, X-ray image view box, tablet, and widow light had lower accuracy than the evaluation on the monitor (p<0.05). Observers diagnostic performances are worsened using window light as an evaluation method for panoramic radiography for dental, sinus, and calcification disorders, while the monitor was the most reliable method.

Resumen El objetivo de este estudio fue evaluar el desempeño diagnóstico de los observadores en la radiografía panorámica utilizando monitor, tablet, caja de visualización de imágenes de rayos X y contra la luz del día de la ventana como método de visualización en diferentes tareas de diagnóstico. Treinta radiografías panorámicas fueron evaluadas por tres observadores calibrados para cada método de visualización, en condiciones de luz estandarizadas, con respecto a caries dental, espacio del ligamento periodontal ensanchado y defectos óseos periapicales de los cuatro primeros molares; engrosamiento de la mucosa y quistes de retención en el seno maxilar; y calcificación y ateroma del ligamento estilohioideo. Se utilizó una escala de confianza de cinco puntos. La referencia estándar fue realizada por dos observadores experimentados. Los valores diagnósticos con luz de ventana fueron significativamente menores para caries y defecto óseo periapical y quiste de retención, detección de calcificación del ligamento estilohioideo (p <0.05). Para la detección de ateroma, la caja de visualización de imágenes de rayos X, el tablet y la luz de viuda tuvieron una precisión menor que la evaluación en el monitor (p <0.05). El rendimiento diagnóstico del observador empeora al utilizar la luz de la ventana como método de evaluación de la radiografía panorámica para los trastornos dentales, de los senos nasales y de la calcificación, mientras que el monitor fue el método más fiable.

DNA damage in an estuarine fish inhabiting the vicinity of a major Brazilian port.

The Itaqui Port Complex (northeastern Brazil) is one of the largest Brazilian port facilities, whose effluents and waste are dumped directly into the estuarine waters. Although environmental monitoring has been a concern around this site, there has been no toxicogenetics study on organisms living in this environment. Thus, we assessed the toxicogenetics potential of the estuarine waters surrounding Itaqui, using the native catfish Sciades herzbergii as a biomonitor. We found a significantly higher frequency of genetic damage and mutations in the animals collected near to Itaqui in both seasons compared to the reference site (distant from Itaqui with no port activities). We also quantified chemical elements in the surface water and sediments near the port and found that clorine, phosphorus, zinc, and boron were above the limits set by the Brazilian legislation. We suggest that such contaminants are involved in the origin of DNA damage. Moreover, we recommend including toxicogenetics assays in the environmental monitoring of pollutants, as well as in the definition of their allowable limits, as they could be used as law enforcement tools and help to predict large-scale contamination events associated with port activities.

Is Panoramic Imaging Equivalent to Cone-Beam Computed Tomography for Classifying Impacted Lower Third Molars?

PURPOSE: Preoperative recognition of the relative position of the mandibular third molars may contribute to more reliable treatment planning, avoiding injuries and decreasing surgical and recovery times. The research questions for this study were as follows: 1) Is panoramic radiography (PR) equivalent to cone-beam computed tomography (CBCT) in determining the degree of mandibular third molar impaction? 2) For PR, is the external oblique ridge a more reliable reference to determine the degree of mandibular third molar impaction? MATERIALS AND METHODS: This retrospective case-series study assessed whether the imaging modalities (primary predictor variable) are equivalent in determining the degree of impaction of third molars (primary outcome variable) according to the parameters of the Pell and Gregory classification. Two oral and maxillofacial radiologists evaluated PR and CBCT images presenting at least 1 mandibular third molar. The degrees of impaction related to the ascending ramus and related to the external oblique ridge (secondary outcome variables) also were assessed. The agreement rates between PR and CBCT were presented, and the imaging modalities were compared by the McNemar-Bowker test (α = .05). RESULTS: A total of 173 patients were included (66 male and 107 female patients). Among these patients, 313 mandibular third molars were assessed. In relation to the occlusal plane, the agreement rate between PR and CBCT was 82.1% for Pell and Gregory class A, 90.5% for class B, and 65.6% for class C (P = .116). The overall agreement rate between the classifications in relation to the mandibular ramus on PR and CBCT ranged from 66.8% (considering the ascending ramus, P < .001) to 76.4% (considering the external oblique ridge, P < .001). CONCLUSIONS: PR performs similarly to CBCT in the classification of impaction in relation to the occlusal plane. However, PR shows a tendency to underestimate the space for accommodation of the third molar compared with CBCT. Furthermore, the external oblique ridge is not a reliable alternative landmark on PR.

Evaluation of the articular eminence and the occlusal surface of the molars by cone beam computed tomography.

The objective of this study was to utilize cone beam computed tomography (CBCT) to evaluate the posterior slope of the articular eminence and the lateral slope of the mandibular fossa in relation to the cusp-fossa angle of the first molars. The evaluation included 93 CBCT images from 93 patients aged 16-30 years. The angle of the posterior slope of the articular eminence was determined from the intersection of a line tangent to the uppermost point of the mandibular fossa and another line tangent to the slope of the anterior wall of the mandibular fossa. The angle of the mandibular fossa slope was determined from the intersection of a line tangent to the most superior point of the mandibular fossa and another line tangent to the slope of the lateral wall of the mandibular fossa. The cusp-fossa relationship of the maxillary and mandibular first molars was also verified on the CBCTs. There was a correlation between the angles of the mandibular left first molar fossa and the lateral slope of the left mandibular fossa. There was also a correlation between the cusp height of the mandibular left first molar and the angle of the lateral slope of the right mandibular fossa. Dentists should consider anatomical factors during restorative, prosthodontic, and orthodontic treatment planning, especially for treatment that will affect the molars, to prevent the development of occlusal interferences that can trigger temporomandibular disorders.

Diagnosis of ethmoid sinolith by cone-beam computed tomography: case report and literature review.

INTRODUCTION: The 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 PRESENTATION: A 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. CONCLUSION: The 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.

Evaluation of Radiopacity of Luting Cements Submitted to Different Aging Procedures.

PURPOSE: To evaluate the radiopacity of luting cements submitted to different aging procedures. MATERIALS AND METHODS: Twenty discs (1 × 4 mm) of each of the following cements were prepared: zinc phosphate, RelyX Luting 2, Variolink 2, AllCem, RelyX U200, Multilink, Panavia F2.0, and RelyX ARC. Then, they were randomly divided into two groups (n = 10/group), according to the aging procedure: thermal cycling group and water storage group. Before and after aging procedures, specimens were x-rayed with an aluminum step-wedge (11 steps, 1 mm thick each) and three dental slices (1 mm thick). The radiopacity was evaluated by means of optical density, which was measured using ImageJ software. The values were converted into millimeters of aluminum with a logistic regression calibration curve. The data were analyzed by one-way ANOVA and Tukey post-hoc test (α = 0.05). RESULTS: In the thermal cycling group, RelyX Luting 2, RelyX U200, and Panavia F2.0 showed a statistically significant reduction in radiopacity (p < 0.05). In the water storage group, all cements showed a significant reduction in radiopacity (p < 0.05), and RelyX Luting 2 and Panavia F2.0 performed below the desired ISO 4049 standard. CONCLUSIONS: The radiopacity of luting cements can decrease after aging, especially after 1-year water storage.

Correlation between midline deviation and condylar position in patients with Class II malocclusion: A cone-beam computed tomography evaluation.

INTRODUCTION: Midline deviation of the mandible and maxilla can affect craniofacial growth and occlusion and cause consequences to the temporomandibular joint. The aim of this study was to evaluate the lateral displacement of the skeletal and dental midlines in relation to the condyle head position in Class II patients with cone-beam computed tomography. METHODS: We used 82 cone-beam computed tomography images. The lateral displacement of the skeletal and dental midlines considering the 3-dimensional reference plane was analyzed with points in the maxillary and mandibular central incisors, anterior nasal spine, and menton. The condyle-fossa relationship, concentric position of the condyles, and dimensional and positional symmetries between the right and left condyles were evaluated. RESULTS: There was a statistically significant difference regarding anterior nasal spine with maxillary central incisor, menton, and mandibular central incisor points for both sides, and also for maxillary central incisor-menton for the displacement of the left side. We found differences in the temporomandibular joint for inclination and diameter measurements of the condylar process. Strong correlations were observed between the maxilla and the condylar process diameter (right side) and the distance between the geometric centers (left side), in addition to a strong correlation between the sagittal midline displacement and the geometric center differences on the right and left sides. CONCLUSIONS: In patients with Class II malocclusion, lateral displacement of skeletal and dental midlines in relation to the condyle head position has a significant correlation with the anteroposterior difference between the geometric center of the right and left condylar processes.

Foreign bodies in the interior of the maxillary sinus: diagnosis by cone beam computed tomography.

To avoid complications, the intimate relation between the maxillary sinus and dental roots deserves attention during surgical procedures. Accidental introduction of foreign bodies, such as dental implants, may irritate the maxillary sinus mucosa, causing sinusitis. Cone beam computed tomography (CBCT) has been proven to be suitable for diagnosis in these cases by providing the exact location of the foreign body. The present article reports 3 cases of foreign bodies inside the maxillary sinus associated with inflammatory processes. Imaging examinations, such as CBCT, are an important tool to assist dentists in diagnosing the presence of foreign bodies in the interior of the maxillary sinus.

Simple bone cyst: rare incidental finding in the mandibular condyle by cone beam computed tomography.

The simple bone cyst (SBC) is a benign intraosseous lesion that is considered to be a pseudocyst because the cystic cavity does not present an epithelial lining. The most accepted theory regarding its etiology is that the SBC develops when the blood clot fails to organize subsequent to bleeding caused by trauma. The SBC is asymptomatic, and therefore the diagnosis is made through routine imaging examinations. In imaging examinations, the lesion is characterized by a radiolucent, unilocular, well-delimited appearance and an irregular or scalloped contour with or without a sclerotic halo. This case report describes an SBC in the mandibular condyle region, discovered incidentally on imaging examinations.

Effect of Alendronate on Bone Microarchitecture in Irradiated Rats With Osteoporosis: Micro-CT and Histomorphometric Analysis.

PURPOSE: The aim of the present study was to evaluate the effect of alendronate (ALN) on the bone microarchitecture of irradiated rats with estrogen deficiency, using microcomputed tomography (micro-CT) and histomorphometric analysis. MATERIALS AND METHODS: Forty adult Wistar rats were subjected to ovariectomy and randomly divided into the following groups: control (CON), ALN, irradiated (IRR), and ALN/irradiated (ALN/IRR). Approximately 50 days after ovariectomy, the hind limbs of the rats in the IRR and ALN/IRR groups were irradiated with 15 Gy of x-radiation. The rats were euthanized 7 and 30 days after irradiation. The bone microarchitecture was analyzed using micro-CT and histomorphometry. The bone microarchitecture was evaluated using the Mann-Whitney U test, analysis of variance, and the post hoc Tukey test, with statistical significance set at 5%. RESULTS: Irradiation had increased the thickness of the cortical bone at 7 days (P < .05) and also decreased the number of trabeculae per unit length and increased the average distance between the trabeculae (P < .05) at 30 days. ALN inhibited the deleterious effect of x-radiation, preventing the distance between the trabeculae from increasing and the number of trabeculae per unit length from decreasing (P < .05). CONCLUSIONS: The present results have demonstrated that the initial effect of ALN could be positive, because it checked the deleterious action in the bone tissue submitted to x-radiation.

Ankylosis of Permanent First Molar: Diagnosis by Cone Beam Computed Tomography / Anquilosis del Primer Molar Permanente: Diagnóstico por Tomografía Computarizada con Haz Cónico

ABSTRACT: Ankylosis is an anomaly of tooth eruption characterized by the fusion of cementum and alveolar bone, and may affect from small regions to the entire root surface. Clinical assessment combined with imaging exams can aid diagnosis. Radiographic testing enables assessing only proximal regions of possibly affected roots. Whereas cone beam computed tomography (CBCT) allows a three-dimensional assessment of axial, coronal, and sagittal planes of all dental extension, eliminating thus overlapping images and helping to confirm the correct diagnosis. The present study contains a case report of a male patient with ankylosis in tooth 16 diagnosed by CBCT, aiming at providing information for dentists about this anomaly, its characteristics and situations in which CBCT should be indicated.

RESUMEN: La anquilosis es una anomalía de la erupción del diente caracterizada por la fusión de cemento y hueso alveolar, y puede afectar desde pequeñas regiones hasta toda la superficie de la raíz. La evaluación clínica combinada con los exámenes de imagen puede ayudar a diagnosticar esta anomalía. Las pruebas radiográficas permiten evaluar sólo las regiones proximales de las raíces posiblemente afectadas. La tomografía computarizada de haz de cono (CBCT) permite una evaluación tridimensional de los planos axial, coronal y sagital de toda la extensión dental, eliminando así las imágenes superpuestas y ayudando a confirmar el diagnóstico correcto. En el presente estudio se presenta un reporte de caso de un paciente con anquilosis en el diente 16 diagnosticado por CBCT, con el objetivo de proporcionar información para los dentistas sobre esta anomalía, sus características y situaciones en las que debe indicarse la CBCT.

Analysis of the correlation between dental arch and articular eminence morphology: a cone beam computed tomography study.

OBJECTIVE: The aim of the study was to assess the correlation between the morphology of the dental arches (DAs) of patients with normal occlusion and of the articular eminence (AE) by using cone beam computed tomography (CBCT). STUDY DESIGN: CBCT scans of 60 patients were evaluated in terms of height and inclinations (angles α, ß, and δ) of the AE. DAs were classified according to their shapes (tapered, square, ovoid), and their perimeters, widths, and depths were measured. One-way analysis of variance, Pearson's correlation coefficients, and simple and multivariate linear regression models were used for the calculations. RESULTS: The ovoid arch was the most predominant shape (n = 66/120). Inclination of the AE (angle ß) had the greatest difference between DA shapes, with this angle usually being greater in the ovoid arch and smaller in the square arch (P < .05). The height of the AE presented greater correlation with DA measurements, with tapered arches having the most significant correlations (P < .05). DA depth had no influence on AE measurements (P > .05). The perimeter and width of the DAs had some influence (P < .05). CONCLUSIONS: Correlations were found between the DA and AE morphologies. The correlations should be taken into consideration, although the results do not prove absolute association between the variables. Whenever possible, the morphologic features of DAs should be preserved to avoid possible changes in AE.

Correlation between the position of hyoid bone and subregions of the pharyngeal airway space in lateral cephalometry and cone beam computed tomography.

OBJECTIVE: To correlate the pharyngeal airway subregions with the positioning of the hyoid bone. MATERIAL AND METHODS: The study examined 107 lateral cephalometric (LC) and cone beam computed tomography (CBCT) images. Linear and volumetric measurements of the pharyngeal subregions were made and correlated to linear measurements using hyoid triangle analysis on images of LC and multiplanar (MPR) and three-dimensional (3D) reconstructions of CBCT. RESULTS: There was significant correlation between linear measurements of the pharyngeal subregions and hyoid bone position in LC images and in MPR and 3D reconstructions of the CBCT. Correlations were more frequent in the oropharynx and hypopharynx, especially for LC images. No correlations were observed between LC images or CBCT reconstructions and the volumetric measurements of the pharyngeal subregions and the position of the hyoid bone. CONCLUSION: The hyoid bone position showed more correlations with oropharynx and hypopharynx airway measurements. The hyoid triangle method was not applicable to 3D images, since it showed a smaller number of measures correlated to the hyoid bone position.

Monostotic fibrous dysplasia: a case report with cone-beam computed tomography findings / Displasia fibrosa monostótica: relato de caso por meio de achados de tomografia computadorizada de feixe cônico

ABSTRACT Fibrous dysplasia is a benign fibrous-osseous lesion in which normal bone is replaced by fibrous connective tissue and immature bone, affecting only one (monostotic) or several bones (polyostotic) and mainly occurring in children and young adults. When present in facial bones, the maxilla is more frequently involved than the mandible, which can cause facial asymmetry in addition to dental complications. In the image exams, the main characteristic of fibrous dysplasia is its unpolished glass appearance. Computed tomography is the ideal method for evaluating this lesion and its relationship with adjacent structures. The use of conventional radiography, due to the overlapping of anatomical structures, makes it difficult to delineate the extension of the lesion. The present study is aimed at guiding dentist-surgeons on the main imaging characteristics of fibrous dysplasia by describing a case of a female 10-year-old patient presenting with this lesion in the maxilla.

RESUMO A displasia fibrosa é uma lesão fibro-óssea benigna em que o osso normal é substituído por tecido conjuntivo fibroso e osso imaturo, podendo afetar um único osso (monostótica) ou vários ossos (poliostótica), ocorrendo principalmente em crianças e adultos jovens. Quando presente nos ossos faciais, a maxila é envolvida com mais frequência que a mandíbula, podendo causar assimetria facial, além de complicações odontológicas. Nos exames por imagem a característica principal da displasia fibrosa é a aparência de vidro despolido. A tomografia computadorizada é o método ideal para avaliação dessa lesão e relação com estruturas adjacentes. A radiografia convencional, devido a sobreposição de estruturas anatômicas, torna difícil a delimitação da extensão da lesão. O presente estudo teve como objetivo apresentar o relato de caso de um paciente do sexo feminino, 10 anos de idade, com presença de displasia fibrosa na maxila, objetivando orientar os cirurgiões-dentistas com relação às principais características imaginológicas dessa lesão.

Cone beam computed tomography in the diagnosis of dens invaginatus: case report / Tomografía computarizada de haz cónico en el diagnóstico de diente invaginado: presentación de un caso

The aim of this report is to present a case of dens invaginatus asymptomatic discovered after exam cone beam computed tomography. A 20-year-old patient attended the clinic Radiology to perform tomography to fracture research at the root of the tooth 15. However, the examination was observed the presence of a conoid supernumerary tooth between the tooth located roots 11 and 12, which had a hyperdense line to the apex of the root, representing the invagination of the enamel, dens invaginatus feature. It was also observed extensive hypodense image in the periapical region, with areas of external resorption both in supernumerary tooth as we ll as the roots of teeth 11 and 12. The treatment consisted of surgery for dens invaginatus extraction. The dentists should be aware of the imaginological characteristics of the anomalies that can affect the teeth/jaws, which can be discovered in tests for routine imaging and proper conduct for the treatment of patients.

El objetivo de este trabajo fue presentar un caso dedens invaginatusasintomático descubierto en una tomografía computarizada de haz cónico. Un paciente de 20 años de edad acudió a la clínica radiológica para realizarse una tomografía producto una fractura radicular del diente 15. Sin embargo, en el exámen se observó la presencia de un diente supernumerario cónico localizado entre las raíces de los dientes 11 y 12, observando además una línea hiperdensa hacia el ápice de la raíz, que representa la invaginación del esmalte, característica propia de undens invaginatus.También se observó un área hipodensa en la región periapical, con áreas de reabsorción externa tanto en el diente supernumerario como en las raíces de los dientes 11 y 12. El tratamiento consistió en cirugía de extracción deldens invaginatus. Los dentistas deben conocer las características imagenológicas de las anomalías que pueden afectar a los dientes, las cuales pueden ser descubiertas en exámenes de rutina y también el protocolo adecuado de tratamiento de éstas.

Micro-CT evaluation of the radioprotective effect of resveratrol on the mandibular incisors of irradiated rats.

The purpose of this study was to perform a microcomputed tomographic evaluation of the radioprotective effect of resveratrol on the volume of mandibular incisors of irradiated rats. A second aim was to make a quantitative assessment of the effect of x-ray exposure on these dental tissues. Twenty adult male rats were divided into four groups: control, irradiated control, resveratrol, and irradiated resveratrol. The resveratrol groups received 100 mg/kg of resveratrol, whereas the irradiated groups were exposed to 15 Gy of irradiation. The animals were sacrificed 30 days after the irradiation procedure, and their mandibles were removed and scanned in a microcomputed tomography unit. The images were loaded into Mimics software to allow segmentation of the mandibular incisor and assessment of its volume. The results were compared by One-way ANOVA and Tukey's post hoc test, considering a 5% significance level. The irradiated groups showed significantly diminished volumes of the evaluated teeth, as compared with the control group (p < 0.05). The resveratrol group presented higher values than those of the irradiated groups, and volumes similar to those of the control group. High radiation doses significantly affected tooth formation, resulting in alterations in the dental structure, and thus lower volumes. Moreover, resveratrol showed no effective radioprotective impact on dental tissues. Future studies are needed to evaluate different concentrations of this substance, in an endeavor to verify its potential as a radioprotector for these dental tissues.

Comparison of different methods to assess alveolar cleft defects in cone beam CT images.

OBJECTIVES: This study aimed to evaluate the accuracy of three different methods for assessing the volume of cleft defects in CBCT images. The influence of field of view (FOV) and voxel sizes was also assessed. METHODS: Using three radio-opaque plastic skulls, unilateral defects were created to mimic alveolar clefts and were filled with wax following the contralateral side contours. They were scanned in a CBCT unit using four different acquisition protocols, varying FOV and voxel sizes. Using three different methods, the defect/wax volume was evaluated on the images by defining: (1) the width, height and facial-palatal length of the defect in maximum intensity projection; (2) the areas of the defect on axial slices; and (3) the threshold and segmentation of the region of interest. The values obtained from each method using different acquisition protocols were compared with the real volume of the wax (gold standard) using ANOVA and Tukey's test. RESULTS: Methods 2 and 3 did not differ from the gold standard (p > 0.05). Conversely, Method 1 presented statistically significant overestimated values (p < 0.01). No differences were found among the different FOV and voxel sizes (p > 0.05). CONCLUSIONS: CBCT volumes proved reliable for the volumetric assessment of alveolar cleft defects, when using Methods 2 and 3 regardless of FOV and voxel sizes. It may be possible to improve surgical planning and outcomes by knowing the exact volume of grafting material needed prior to the surgical intervention.