Prevalence of Errors and Number of Retakes in Panoramic Radiography: Influence of Professional Training and Patient Characteristics

ABSTRACT: Panoramic radiography has clinical importance in several dental specialties. The objective of this study was to evaluate the influence of professionals' experience and patient characteristics (age group and dental absence) in the prevalence of errors and the number of retakes in the panoramic radiography.771 panoramic radiographs were evaluated and classified according to the group of patients (children, dentulous adults, total edentulous adults, and anterior edentulous adults) and professionals who performed the technique (novice and experienced). The association between frequency and type of error, group of patients, professionals' experience, and number of retakes was performed by the Chi-square and Fisher's exact test (a=0.05). There was no significant association between the frequency of errors or retakes of the radiograph s and the professionals' experience or patients' characteristics (p<0.05). The errors "turned head" and "tongue not against the palate," "chin tipped low", "chin not resting on the support," "patient movement during exposure," and "lead apron artifact" showed significantly higher frequency of retake (p<0.05). The most frequent type of error was due to the failure to position the tongue against the palate for all patients and both groups of professionals. The frequency of errors in the panoramic radiography occurs regardless of the professionals' experience, and age and dental absence of the patients. Error occurs mainly due to the lack of patient collaboration, and the examination is rarely repeated by the professionals.

RESUMEN: La radiografía panorámica es de importancia clínica en varias especialidades dentales. El objetivo de este estudio fue evaluar la experiencia de los profesionales y las características de los pacientes (grupo etario y ausencia dentaria) en la prevalencia de errores y el número de repeticiones en la radiografía panorámica.771 radiografías panorámicas fueron evaluadas y clasificadas según la grupo de pacientes (niños, adultos desdentados, adultos desdentados totales y adultos desdentados anteriores) y profesionales que realizaron la técnica (novatos y experimentados). La asociación entre frecuencia y tipo de error, grupo de pacientes, experiencia de los profesionales y número de repeticiones se realizó mediante la prueba de Chicuadrado y exacta de Fisher (a = 0,05). No hubo asociación significativa entre la frecuencia de errores o repetición de las radiografías y la experiencia de los profesionales o las características de los pacientes (p <0,05). Los errores "cabeza girada" y "lengua no contra el paladar", "mentón inclinado hacia abajo", "mentón no apoyado en el soporte", "movimiento del paciente durante la exposición" y "artefacto del delantal de plomo" mostraron una frecuencia de repetición significativamente mayor (p < 0,05). El error más frecuente se debió a la falta de posicionamiento de la lengua contra el paladar para todos los pacientes y en ambos grupos de profesionales. La frecuencia de errores en la radiografía panorámica ocurre independientemente de la experiencia de los profesionales, edad y ausencia dentaria del pacientes. El error se produce principalmente por la falta de colaboración del paciente, y los profesionales rara vez repiten el examen.

Does the administration of meloxicam before head and neck radiotherapy reduce the risk of mandibular osteoradionecrosis? An animal model study.

OBJECTIVE: To assess whether the administration of meloxicam before head and neck radiotherapy reduces the risk of mandibular osteoradionecrosis in rats. MATERIAL AND METHODS: Sixty male Wistar rats were randomly divided into 6 groups (n = 10) according to the meloxicam administration and radiation therapy: control (C), irradiated (I), single dose of meloxicam (M1), single dose of meloxicam and irradiated (M1I), triple dose of meloxicam (M3), triple dose of meloxicam and irradiated (M3I). Meloxicam was administrated (20 mg/kg per dose) 1 h before the radiation therapy (single dose of 20 Gy) and 24 h and 48 h after the radiation therapy for groups with two additional doses. Ten days after the radiation therapy, the three right mandibular molars were extracted from all rats, who were euthanatized after 21 or 35 days (n = 5 per group). The mandibles were assessed by macroscopic evaluation and micro-CT analysis. RESULTS: The right hemimandibles of the irradiated groups revealed macroscopic signs of osteoradionecrosis, and those of the non-irradiated groups revealed complete gingival healing. A significant delay in alveolar socket healing in all irradiated groups was observed in the micro-CT assessment regardless meloxicam treatment. CONCLUSION: The administration of meloxicam before head and neck radiotherapy does not reduce the risk of mandibular osteoradionecrosis when associated to dental extractions. CLINICAL RELEVANCE: Since meloxicam has been shown to be a potential radiation-protective agent, and osteoradionecrosis physiopathology is believed to be related to an inflammatory process, possible interactions are relevant to be investigated.

Distribution of metal artifacts arising from the exomass in small field-of-view cone beam computed tomography scans.

OBJECTIVES: To evaluate the distribution of metal artifacts from the exomass in small field-of-view (FOV) cone beam computed tomography (CBCT) scans. STUDY DESIGN: An image phantom was scanned by using 3 CBCT units. Metal objects were positioned in the exomass, and additional CBCT scans were obtained. Mean gray values were obtained from 16 homogeneous areas and the standard deviation was calculated to quantify gray level inhomogeneity according to distinct zones of the FOV: total area and outer, inner, right, left, and mid-zones. The discrepancy between each zone and the total area was calculated to compare different CBCT units. Mean gray, gray level inhomogeneity, and discrepancy values were separately assessed by using analysis of variance (ANOVA) and Tukey's test (α = 0.05). RESULTS: Overall, the mean gray values were significantly lower in the inner zone, and the gray level inhomogeneity values were significantly higher in the inner and mid-zones irrespective of the presence of metal objects in the exomass. The 3 CBCT units presented significantly different discrepancy values in most conditions. CONCLUSIONS: The distribution of metal artifacts from the exomass follows the inherent gray value dispersion of CBCT images, with greater inhomogeneity in the inner zone of the FOV. This is exacerbated when metal objects are in the exomass.

Is the digital radiographic detection of approximal caries lesions influenced by viewing conditions?

OBJECTIVES: The aim of this study was to assess the influence of different viewing conditions (combinations of computer display, horizontal viewing angle, and ambient lighting) on the detection of approximal caries lesions on digital radiographic images. STUDY DESIGN: Forty posterior teeth were mounted in a plaster block and radiographed by using a CMOS sensor-based system. Three oral radiologists assessed the radiographic images under different conditions of computer display (iMac 5K 27", Barco MDRC-2124, and Dell P2314H), horizontal viewing angles (90 degrees, 67.5 degrees, and 45 degrees), and ambient lighting (low, medium, and high) and were asked to detect the presence of approximal caries lesions, which were confirmed by means of micro-computed tomography (micro-CT), using a 5-point scale. The area under the receiver operating characteristic curve, sensitivity, and specificity were calculated and compared by analysis of variance testing (α = 0.05). Intra- and interobserver agreements were assessed with the Kappa test. RESULTS: Computer display, horizontal viewing angle, and ambient lighting did not significantly influence the diagnosis of approximal caries lesions. In general, moderate values of accuracy, low sensitivity, and high specificity were found for all viewing conditions. CONCLUSIONS: The viewing conditions assessed in this study did not influence the detection of approximal caries lesions on digital radiographic images. Dental practitioners are encouraged to find their most comfortable viewing condition for this diagnostic task.

A modified protocol of mandibular osteoradionecrosis induction in rats with external beam radiation therapy.

OBJECTIVE: To propose a modified protocol of mandibular osteoradionecrosis induction in rats with external beam radiation therapy. MATERIAL AND METHODS: A total of 45 male Wistar rats were used in this study. Firstly, 25 rats were divided into 5 groups (n = 5) according to the radiation dose protocol: without irradiation and irradiated with 15 Gy, 20 Gy, 25 Gy, or 30 Gy using a linear accelerator. Secondly, 15 other rats were divided into 3 groups (n = 5) according to the time of extraction of the three right mandibular molars: 7, 10, or 14 days after irradiation of 20 Gy. Lastly, dental extractions were performed in 5 other rats without irradiation (C-E10) for comparison with those of the group of dental extractions 10 days after irradiation (I-E10). RESULTS: The irradiated animals survived throughout the study period only at single doses of 15 Gy and 20 Gy. The suitable time for dental extractions after irradiation to induce mandibular osteoradionecrosis was defined as 10 days. Macroscopic evaluation of the right hemimandibles showed presence of osteoradionecrosis in I-E10 group and complete gingival healing in C-E10 group. CONCLUSION: A single radiation dose of 20 Gy focused on head and neck region combined with the extraction of the three mandibular molars 10 days after irradiation constitutes a feasible protocol of mandibular osteoradionecrosis induction in rats with external beam radiation therapy. CLINICAL RELEVANCE: Establishing a solid and widely available protocol of mandibular osteoradionecrosis induction is essential in the search for methods to prevent this complex disease.

Automatic exposure compensation and subjective image enhancement in the radiographic diagnosis of caries

Abstract This study aims to assess the influence of high-density material on the radiographic diagnosis of proximal caries in digital systems with automatic exposure compensation, and to evaluate the effect of subjective adjustment of brightness and contrast to undertake this diagnostic task. Twenty bitewing radiographs of forty posterior human teeth with non-cavitated carious lesions, confirmed by micro-CT, were obtained with two digital systems. A porcelain-fused-to-metal crown attached to a titanium implant was inserted into the exposed area, and all the radiographs were repeated. Five radiologists assessed the radiographs and diagnosed proximal carious lesions. Afterwards, the observers were asked to adjust image brightness and contrast, based on their subjective perception, and to reassess the images. Thirty percent of each experimental group was reassessed to test intraobserver reproducibility, totaling 208 images per observer. Intraobserver and interobserver agreements ranged from fair to substantial. Sensitivity, specificity, predictive values, and area under the ROC curve were calculated and compared for each radiographic system, using ANOVA (α = 0.05). Overall, presence of high-density material and adjustment of brightness and contrast did not significantly influence the radiographic diagnosis of proximal caries (p ≥ 0.05). Regarding Digora Optime, adjustment of brightness and contrast significantly increased (p < 0.05) the diagnostic accuracy of proximal carious lesions in the presence of high-density material. In conclusion, the presence of high-density material in the X-rayed region does not influence radiographic diagnosis of proximal caries. However, when it is present in the X-rayed area, subjective adjustment of brightness and contrast is recommended for use with the Digora Optime digital system.

Treatment outcomes of pulp revascularization in traumatized immature teeth using calcium hydroxide and 2% chlorhexidine gel as intracanal medication

Abstract Objective Pulp revascularization is an effective treatment for immature necrotic teeth. Calcium hydroxide has been used in pulp revascularization as an intracanal medication due to its antimicrobial action and the non-exhibition of crown discoloration and cytotoxicity for stem cells from the apical papilla. Our study aimed to investigate the clinical success and quantitative radiographic changes of root development in immature traumatized teeth using calcium hydroxide plus 2% chlorhexidine gel as intracanal medication. Methodology In this retrospective study, 16 patients were treated with a standardized pulp revascularization protocol. Calcium hydroxide and 2% chlorhexidine gel were manipulated in a 1:1 (v/v) ratio and inserted into root canals with Lentulo spirals (Dentsply Maillefer, Baillaigues, Switzerland). Patients were followed up for a period from 9 to 36 months for the evaluation of clinical and radiological data. Radiographic measurements of root length, root width, apical diameter, and MTA placement from the apex were quantified using software ImageJ. Wilcoxon test and t-test were used, according to nonparametric or parametric data, respectively, for changes over time in root length, root width, and apical diameter. Results Fifteen teeth survived during the follow-up period (93.75%) and met the criteria for clinical success. Although the changes seem to be very small in many cases, significant increases in the average root length (14.28%, p<0.0001), root width (8.12%, p=0.0196), and decrease in apical diameter (48.37%, p=0.0007) were observed. MTA placement from the apex and age at the time of treatment was not significantly associated with the quantitative radiographic outcomes. Conclusions Pulp revascularization in traumatized immature teeth treated with calcium hydroxide plus 2% chlorhexidine gel as intracanal medication had high success and survival rates, showing periodontal healing and resolution of signs and symptoms. However, concerning the continued root development, the outcomes can still be considered unpredictable.

Influence of phosphor plate-based radiographic image specifications on fractal analysis of alveolar bone.

OBJECTIVE: The aim of this study was to evaluate the influence of spatial resolution, bit depth, and enhancement filters on the fractal dimension (FD) of photostimulable phosphor (PSP) plate-based intraoral radiographic images of alveolar bone. STUDY DESIGN: Periapical radiographs were obtained using PSP plates, which were scanned at 2 spatial resolutions: 1270 dpi and 2000 dpi. All images were subjected to 3 enhancement filters-Perio, Endo, and Fine-and exported in 8 and 16 bits. A region-of-interest was selected on alveolar bone and the FD value was calculated. The multiway analysis of variance test followed by the post hoc Tukey test compared the FD values between the different groups (α = 0.05). RESULTS: No significant difference was observed in FD values between the 8- and 16-bit images. Except for the Perio filter, FD values were significantly higher for images at 1270 dpi. FD values were significantly higher for the Perio filter, followed by the Endo filter, and the Fine filter. The FD values of the Fine filter did not differ significantly from the original image. CONCLUSIONS: Fractal analysis of alveolar bone obtained from PSP plate-based intraoral radiographic images is influenced by spatial resolution and some digital enhancement filters; therefore, for FD comparison purposes, images should have the same specifications.

Brightness and contrast adjustments influence the radiographic detection of soft tissue calcification.

OBJECTIVE: To assess the influence of subjective enhancement of brightness and contrast of digital panoramic radiographs on the detection of soft tissue calcifications. MATERIALS AND METHODS: In this observational study, 500 digital panoramic radiographs were evaluated by two examiners in consensus, who scored the images for the presence of calcifications for each right and left side of the image. After 30 days, all images were revaluated under subjective manipulation of digital brightness and contrast. Calcifications were classified based on the diagnostic hypothesis: sialolith, tonsillolith, calcified atheroma, phlebolith, rhinolith, maxillary sinus antrolith, synovial chondromatosis, lymph node calcification, stylohyoid ligament, triticeous cartilage, or/and upper horn of thyroid cartilage calcification. For intra-examiner agreement, 20% of the sample was reevaluated. The Kappa test and McNemar test were used (α = 0.05). RESULTS: In original images, calcifications were observed in 44.2% of the patients, and in enhanced images, this number was 70.8%. Many calcifications were detected only in enhanced images, mainly in the diagnostic hypotheses of calcified atheroma and stylohyoid ligament. Intra-examiner agreement was excellent for the detection of soft tissue calcifications (0.82) and for the classification (0.81). CONCLUSION: Subjective enhancement of brightness and contrast alters the detection of soft tissue calcifications in digital panoramic radiograph.

Influence of interpretation conditions on the subjective differentiation of radiographic contrast of images obtained with a digital intraoral system.

OBJECTIVES: The aim of this study was to evaluate interpretation conditions in the subjective in vitro assessment of dental tissue-equivalent radiographic contrast. STUDY DESIGN: Radiographic images with the density of dental structures were randomized and arranged in 20 sequences with images juxtaposed and separated. Twelve observers interpreted the sequence among the most radiolucent and radiopaque images with 3 displays, 3 horizontal viewing angles, and 3 ambient light conditions. The evaluation time was recorded. The hit percentage was calculated for each evaluation. Three-way analysis of variance with Tukey's test was used to compare the conditions of interpretation. The intraclass correlation coefficient was used to assess agreement (α = 0.05). RESULTS: No differences in hit percentages were found among the 3 displays or among the juxtaposed and separated images. Increased hit percentages were recorded for images assessed at 90° compared with 45° for all displays and in high ambient light vs intermediate and low light at 90°. Increased evaluation time was recorded for the consumer-grade display under high ambient light and for the separated images. CONCLUSIONS: The subjective in vitro assessment of dental tissue-equivalent radiographic contrast is not influenced by computer display, which should be viewed at a horizontal viewing angle of 90° and under high ambient light. Longer evaluation times may be expected with consumer-grade displays.

Morphological Evaluation of the Nasopalatine Canal in Patients With Different Facial Profiles and Ages.

PURPOSE: To evaluate the influence of facial profile and age on the morphology of the nasopalatine canal. MATERIALS AND METHODS: One hundred thirty-two cone-beam computed tomograms were classified according to facial profile-mesofacial, brachyfacial, and dolichofacial-and divided into the following age groups: 21 to 30, 31 to 40, 41 to 50, and 51 to 60 years. Measurements were obtained for openings of the incisive and nasopalatine foramina, alveolar bone thickness, and the full length, most constricted region, and volume of the nasopalatine canal. Intra- and inter-examiner agreements were calculated using the intraclass correlation coefficient. After exploratory and descriptive analysis, data were subjected to 2-way analysis of variance and Tukey test for comparisons between facial profiles and age groups. The significance level was 5% (α = 0.05). RESULTS: Intra- and inter-examiner reproducibilities were excellent for all measurements. Patients older than 50 years presented a significantly larger nasopalatine canal than patients 21 to 30 years old for all facial profiles (P ≤ .05). Linear measurements obtained from the nasopalatine canal showed no significant difference between facial profiles and age groups (P > .05). CONCLUSIONS: The nasopalatine canal was not influenced by facial profile but did exhibit an increased volume with aging, particularly after 50 years of age.

Are metal artefact reduction algorithms effective to correct cone beam CT artefacts arising from the exomass?

The aim of this study was to evaluate the effectiveness of metal artefact reduction (MAR) in cone beam CT (CBCT) artefacts arising from metallic objects in the exomass. A radiographic phantom composed of 16 polypropylene tubes filled with a homogeneous radiopaque solution was created. CBCT scans were obtained with two units: Picasso Trio (Vatech, South Korea) and ProMax (Planmeca, Finland). The phantom was centred in a 5 × 5 cm field-of-view (FOV) with titanium and CoCr inserts in the exomass. All scans were repeated after enabling MAR. Mean voxel values were obtained from the 16 tubes and standard deviation was calculated as a way of measuring voxel value variability. Mean values and voxel value variability were compared individually in the presence and absence of MAR by means of analysis of variance, followed by Tukey's test (α = 0.05). In the Picasso Trio, MAR significantly decreased mean voxel values (p ≤ 0.05) and increased voxel value variability (p > 0.05) in the presence of titanium. When CoCr was present, no statistical difference (p > 0.05) was observed. In the ProMax, MAR increased significantly mean voxel values (p ≤ 0.05) in the presence of titanium, and presented no significant difference (p > 0.05) for CoCr. Voxel value variability did not differ significantly (p > 0.05) for both materials. In conclusion, MAR was not effective to correct CBCT artefacts arising from metallic objects in the exomass in the two CBCT units used.

Diagnostic value of magnetic resonance imaging in the analysis of ameloblastoma: report of two cases / Valor diagnóstico da ressonância magnética na análise do ameloblastoma: relato de dois casos

Ameloblastoma is an odontogenic tumor that shares clinical and imaging characteristics with other lesions of the jaws, such as odontogenic keratocyst, which makes the diagnosis difficult.However, in addition to radiographic and tomographic examinations, Magnetic Resonance Imaging (MRI) has been increasingly used, contributing with relevant additional information about thedifferentiation between solid and liquid components of the lesion. This case report was conducted to present two variations of ameloblastoma and discuss the radiographic, tomographic and MRI contribution in the differential diagnosis between ameloblastoma and odontogenic keratocyst. The signal intensity in T1-weighted MRI revealed internal fluid content in both cases, which was important in the differential diagnosis with other intraosseous lesions such as odontogenic keratocysts. This is probably due to the presence of keratin that increases the viscosity of the content and also for an intermediate signal intensity signal in T2-weighted MRI. Therefore, MRI revealed important internal characteristics of the reported lesions, which was very useful in the establishment of the differential diagnosis with other lesions. (AU)

O ameloblastoma é um tumor odontogênico que compartilha características clínicas e de imagem com outras lesões da mandíbula, como o ceratocisto odontogênico, o que dificulta o seu diagnóstico. Entretanto, além dos exames radiográficos e tomográficos, a ressonância magnética (RM) tem sido cada vez mais utilizada, contribuindo com informações adicionais relevantes sobre a diferenciação entre componentes sólidos e líquidos da lesão. Este relato de caso apresenta duas variações de ameloblastoma e discuti a contribuição radiográfica, tomográfica e da RM no diagnóstico diferencial entre o ameloblastoma e o ceratocisto odontogênico. A RM ponderada em T1 revelou conteúdo líquido interno em ambos os casos relatados, o que foi importante no diagnóstico diferencial com outras lesões intraósseas, como os ceratocistos odontogênicos. Isto ocorre devido à presença de queratina aumentar a viscosidade do conteúdo e também gerar um sinal de intensidade intermediária na RM ponderada em T2. Portanto, a RM revelou importantes características internas das lesões relatadas, o que foi muito útil no estabelecimento do diagnóstico diferencial com outras lesões. (AU)

Clinical implications, diagnosis, and treatment of a giant frontoethmoid osteoma.

Osteomas are benign, asymptomatic fibro-osseous tumors that are most commonly observed in the paranasal sinuses and sometimes are found in imaging examinations that were taken for other reasons. Giant osteomas are rarely found in the frontal and ethmoid sinuses but, when they are, they may cause intracranial and orbital complications. The aims of this case report are to describe a frontoethmoid osteoma in a 40-year-old woman, discuss the characteristics of this lesion through cone beam computed tomography (CBCT) imaging, and review the options for treatment. A CBCT examination performed for the purpose of orthodontic diagnosis revealed the presence of a large, well-defined, lobular, hyperdense mass that occupied a sizeable area of the frontal sinus and extended to the ethmoid sinus. The patient did not report any pain. Based on the physical and imaging characteristics of the mass, the location and size of the lesion, and the patient's age, the diagnosis was a giant frontoethmoid osteoma. Due to its enhanced field of view, CBCT may enable earlier diagnosis of lesions that affect the maxillofacial region.

Automatic cephalometric analysis: is it time to switch to a hands-free method?

Aim: To evaluate the reliability of the automatic cephalometric analysis in relation to the semi-automatic method. Methods: Fifty lateral cephalometric radiographs were selected and two dental surgeons performed the Steiner and Tweed analyses independently using the semi-automatic method on the Radiocef Studio 2® software suite (Radiomemory, Belo Horizonte, MG, Brazil), and the automatic method on the Kodak Dental Imaging Software (Carestream Health, Rochester, NY, USA). After thirty days, 30% of the sample was re-evaluated to assess intra-observer agreement. Ten angular and linear measurements of both analyses were selected, averaged for both observers and compared using Student's t-test with a significance level of 5% (α=0.05). Intra and inter-observer agreement were assessed through Intraclass Correlation Coefficient. Results: Intra-observer reproducibility was excellent for all measurements and inter-observer reproducibility was excellent for most of them. Significant differences (p<0.05) were found between automatic and semi-automatic methods for all measurements. Most of the measurements were significantly higher (p<0.05) with the automatic method. Conclusion: Semi-automatic cephalometric analysis can not be replaced with a completely automatic method

Influence of acquisition parameters on the evaluation of mandibular third molars through cone beam computed tomography.

OBJECTIVES: The aim of the study was to assess the influence of cone beam computed tomography (CBCT) acquisition parameters on the evaluation of mandibular third molars and their relationship to the mandibular canal. STUDY DESIGN: Eight dry human mandibles with 13 mandibular third molars were scanned with one CBCT unit. Voxel size (0.2 and 0.3 mm), field of view (FOV) size (12 × 8.5 cm and 5 × 5 cm), and number of basis images (450 and 720) were the variables studied. Two examiners evaluated the images, and the resulting data were compared through McNemar, McNemar-Bowker, and Student t tests. Additionally, dosimetry was determined for all protocols tested, and radiation doses were compared through analysis of variance. RESULTS: The variables did not influence evaluation of mandibular third molars, except for voxel size, when assessing contact between the tooth and the mandibular canal (P = .021). Although FOV and number of basis images affected radiation dose, voxel size did not. CONCLUSIONS: FOV size and number of basis images did not influence the evaluation of mandibular third molars and their relationship to the mandibular canal in the CBCT unit used. Conversely, smaller voxel size affected the assessment of contact between the tooth and the mandibular canal. In units in which voxel size does not influence radiation dose, the most appropriate CBCT protocol is the one using a smaller voxel size and delivering the lowest radiation dose to the patient.

Evaluation of the efficacy of a metal artifact reduction algorithm in different cone beam computed tomography scanning parameters.

OBJECTIVE: The aim of this study was to evaluate the efficacy of a metal artifact reduction (MAR) algorithm in cone beam computed tomography (CBCT) images of dental materials obtained with different field-of-view (FOV) and voxel sizes. STUDY DESIGN: Two imaging phantoms were custom-made of acrylic resin. Each phantom had 3 cylinders made of the same dental material: dental amalgam or copper-aluminum alloy. CBCT scans were obtained separately for each of the imaging phantoms using the Picasso-Trio CBCT (Vatech, Hwaseong, Republic of Korea) unit at 4 FOV sizes and 2 voxel sizes. Each imaging phantom was scanned with and without MAR. All images were evaluated in the OnDemand3D software (Cybermed, Seoul, Republic of Korea) and image noise (gray value variability) was calculated as the standard deviation (SD) of the gray values of regions of interest around the dental material cylinders. Data were compared by the Friedman test and Dunn test (α = 0.05). Intraclass correlation coefficient (ICC) was calculated to assess intraobserver reliability. RESULTS: MAR significantly reduced (P < .05) image noise around the dental materials, irrespective of FOV and voxel sizes, with an ICC of 0.997. CONCLUSIONS: The efficacy of MAR was similar for the different FOV and voxel sizes studied. Hence, imaging protocols and the use of MAR algorithm should be based on the selection criteria.

Aspectos tomográficos de ameloblastoma multicístico de células granulares: relato de caso / Computed tomography imaging features of multicystic granular cell ameloblastoma: a case report

O ameloblastoma multicístico é uma variante clínica do ameloblastoma, muitas vezes localmente agressivo, com significante aumento de morbidade e mortalidade. O ameloblastoma é frequentemente assintomático, sendo identificado incidentalmente durante exames odontológicos de rotina. Trata-se de uma lesão de crescimento lento e persistente, podendo ser notada, em alguns casos, uma expansão gradual da mandíbula, produzindo assimetria facial. Ameloblastomas raramente apresentam um comportamento maligno. A avaliação clínica inclui uma revisão cuidadosa da história clínica do paciente, bem como exame físico da cabeça e pescoço. Modalidades de imagens radiográficas são úteis para localizar a lesão, avaliar suas dimensões e os efeitos sobre as estruturas adjacentes. O manejo da lesão representa um desafio para todos os profissionais envolvidos na área de cirurgia de cabeça e pescoço. Assim, o objetivo deste trabalho foi descrever as características tomográficas de um ameloblastoma multicístico de células granulares em um paciente do sexo masculino, leucoderma, de 40 anos de idade...

Multicystic ameloblastoma is a clinical variant of ameloblastoma. It is often locally aggressive with significant impact on patient morbidity and mortality. Ameloblastoma is often asymptomatic and is usually detected as an incidental finding during routine dental examinations. It presents slow and persistent growth; in some cases a gradual expansion of the jaw producing facial asymmetry may be noticed . Although the occurrence is rare, ameloblastomas can exhibit malignant behavior and metastasize. Clinical evaluation includes careful review of the patient's medical history and physical examination of the head and neck region. Radiographic imaging techniques are useful for locating the lesion, estimating its dimensions and assessing its effects on adjacent structures. Management of ameloblastoma is a challenge for all involved in the field of head and neck surgery. The aim of this paper was therefore to describe the tomographic features of a multicystic granular cell ameloblastoma in a 40-year-old white male patient...

Comparative analysis of mandibular anatomical variations between panoramic radiography and cone beam computed tomography.

PURPOSE: The objective of this study is to compare the ability of panoramic radiography and cone beam computed tomography (CBCT) in detecting anatomical variations of the mandibular canal and mental foramen. METHODS: One hundred twenty-seven preoperative panoramic and CBCT images were evaluated. Two oral and maxillofacial radiologists investigated the presence of bifid mandibular canals and/or additional mental foramina on the right, left, or both sides of the mandible. Intra- and interobserver reliability was determined using Cohen's kappa coefficient. McNemar's test compared the prevalence of mandibular anatomical variations between panoramic radiography and CBCT. The significance level was set at 0.05. RESULTS: Additional mental foramen and bifid mandibular canal were detected in 1.2 and 7.4 % of the panoramic radiographs and 7.4 and 9.8 % of the CBCT images, respectively. The incidence of anatomical variations on the mandibular canal was not significantly different between both imaging modalities (P > 0.05). CONCLUSIONS: Although CBCT provides better viewing of anatomical structures, including location, shape, and relationship with the surrounding area, panoramic radiography is a conventional imaging modality that can be used in the study of the bifid mandibular canals.

Gardner's syndrome suggested by radiographic findings / Síndrome de Gardner sugerida por achados radiográficos

Gardner's syndrome (GS) is a hereditary disorder characterized by multiple osteomas, enostosis, epidermoid cysts, subcutaneous desmoid tumors and multiple gastrointestinal polyps. Given the variety of clinical manifestations, the triad of symptoms that better characterizes the GS is composed by polyps of the colon, multiple osteomas and tumors of soft tissue. The osteomas are most common in the frontal bone and mandible. A significant feature of GS is the progression to malignancy of the intestinal polyps in almost 100% of patients. Early detection of GS allows for an excellent prognosis and may be a lifesaving event. Thus, the aim of this case report was to describe the radiographic aspects of GS in the dentomaxillofacial region and to discuss with the current scientific literature.

A síndrome de Gardner (SG) é uma desordem caracterizada por múltiplos osteomas, enostosis, cistos epidermoides, tumores desmoides subcutâneos e múltiplos pólipos gastrointestinais. Considerando a variedade de manifestações clínicas, a tríade dos sintomas que melhor caracterizam a SG é composta por pólipos do cólon, múltiplos osteomas e tumores de tecido mole. Os osteomas são mais comuns no osso frontal e mandíbula. Uma característica significativa da SG é a progressão maligna dos pólipos intestinais em aproximadamente 100% dos pacientes. A detecção precoce da SG favorece um excelente prognóstico e pode salvar vidas. Então, o objetivo deste relato de caso foi descrever os aspectos radiográficos da SG na região dento-maxilo-facial e discutir com a literatura científica atual.