Effect of Different Cone Beam Computed Tomography Devices and Protocols on Image Quality for the Evaluation of Periodontal Structures / Efeito de Diferentes Dispositivos e Protocolos de Tomografia Computadorizada deFeixe Cônico na Qualidade de Imagem para Avaliação de Estruturas Periodontais

The quality of Cone Beam Computed Tomography (CBCT) images is directly influenced by scanning and visualization protocols. Evaluate the subjective quality of the Cone Beam Computed Tomography (CBCT) image of different devices and protocols for diagnosing periodontal structures and correlate the findings with the contrast-to-noise ratio (CNR). One dry dentate mandible was scanned by six CBCT devices: Accuitomo 3D 170, CS 9000, CS 9300, Eagle 3D, i-CAT Classic, and Orthophos XG 3D. All CBCT devices were adjusted to provide a spatial resolution closest to 0.2 mm, and a FOV height limited to less than 100 mm. Cross-sectional images were evaluated randomly. The buccal bone coverage, the periodontal ligament space and the amount of image noise were assessed. The statistics were calculated based on a logistic regression model with the significance level set at 5%. Protocols with large FOVs demonstrated significantly lower image quality. No statistical differences were found regarding buccal bone coverage between the CBCT devices. The CNR showed the highest value for the Accuitomo 60mm x 60mm HiFi 180°, followed by the Accuitomo 60mm x 60mm HiFi 360°, and lower values for the i-Cat Classic and Orthophos XG 3D devices. Most protocols studied presented good image quality in evaluating the buccal bone coverage and periodontal ligament space. However, the exam with the lowest FOV of the Accuitomo 60mm x 60mm HiFi 180° device showed superiority concerning the others.(AU)

A qualidade das imagens de tomografia computadorizada de feixe cônico (CBCT) é diretamente influenciada pelos protocolos de digitalização e visualização. Avaliar a qualidade subjetiva da imagem da Tomografia Computadorizada de Feixe Cone (CBCT) de diferentes aparelhos e protocolos para o diagnóstico de estruturas periodontais e correlacionar os achados com a razão contraste-ruído (RCR). Uma mandíbula dentada seca foi digitalizada por seis dispositivos CBCT: Accuitomo 3D 170, CS 9000, CS 9300, Eagle 3D, i-CAT Classic e Orthophos XG 3D. Todos os dispositivos CBCT foram ajustados para fornecer uma resolução espacial próxima a 0,2 mm e uma altura de FOV limitada a menos de 100 mm. Imagens transversais foram avaliadas aleatoriamente. A cobertura óssea vestibular, o espaço do ligamento periodontal e a quantidade de ruído da imagem foram avaliados. As estatísticas foram calculadas com base em um modelo de regressão logística com nível de significância de 5%. Protocolos com grandes FOVs demonstraram qualidade de imagem significativamente inferior. Não foram encontradas diferenças estatísticas em relação à cobertura óssea vestibular entre os dispositivos CBCT. O CNR apresentou o maior valor para o Accuitomo 60mm x 60mm HiFi 180°, seguido pelo Accuitomo 60mm x 60mm HiFi 360°, e valores menores para os dispositivos i-Cat Classic e Orthophos XG 3D. A maioria dos protocolos estudados apresentou boa qualidade de imagem na avaliação da cobertura óssea vestibular e do espaço do ligamento periodontal. Entretanto, o exame com menor FOV do aparelho Accuitomo 60mm x 60mm HiFi 180° apresentou superioridade em relação aos demais. (AU)

Tomographic evaluation of buccal bone in different skeletal patterns and incisors inclination.

OBJECTIVE: The aim of this study was to correlate the absence of BB with skeletal patterns and incisor inclination using cone-beam computed tomography (CBCT). METHODS: The sample comprised CBCT images of 45 patients undergoing orthodontic treatment. BB was classified in each third of the anterior teeth as critical, slender, regular, and thick. The skeletal pattern was determined by the ANB (A point, nasion, B point) angle and the incisor inclination using the 1.NA and 1.NB measurements and the interincisal angle (1:1). RESULTS: In both analyses, the skeletal pattern of class II revealed better BB in the cervical and middle thirds than classes I and III. A higher proportion of critical BB was found in the middle thirds, and the apical third presented the best regular and thick BB conditions, mainly class I. Less BB was observed in middle and apical thirds in the upper incisors and in cervical thirds in lower incisors, mostly when they were more upright. CONCLUSIONS: Knowledge of alveolar bone height and thickness can alter the treatment plan in orthodontics. During orthodontic treatment, more attention should be paid to the lower incisors and vertical teeth because of poor BB conditions, especially in class III skeletal patterns.

Abordagem cirúrgica conservadora de fibroma ossificante em localização atípica da mandíbula: relato de caso / Conservative surgical approach of ossifying fibroma in atypical location of the jaw: case report

O fibroma ossificante (FO) é uma neoplasia fibro-óssea benigna da região craniofacial de origem odontogênica, formado a partir de células mesenquimais multipotentes do ligamento periodontal, as quais são capazes de formar osso, tecido fibroso e cemento. Acredita-se que exodontias prévias, infecções, trauma ou uma perturbação de origem congênita na maturação óssea poderiam servir como fatores predisponentes para o desenvolvimento do FO. Radiograficamente, as lesões de FO iniciais são representadas por uma imagem radiolúcida, unilocular, redonda ou oval, de margem bem circunscrita. No estágio tardio, o componente mineralizado é circundado por uma fina cápsula fibrosa representada por uma linha radiolúcida delgada, que envolve toda a lesão. O objetivo deste trabalho é discutir a abordagem cirúrgica de um FO localizado em região atípica da mandíbula. Relato de caso: paciente leucoderma, 18 anos de idade, sexo feminino, cursando com aumento de volume em região posterior mandibular direita. No exame de imagem, identificou-se uma lesão mista, bem definida, não corticalizada, medindo aproximadamente 3 cm x 2,5 cm. Após realização de biópsia incisional, confirmou-se o diagnóstico de FO. Sendo assim, optou-se pela curetagem acompanhada de uma osteotomia periférica da lesão e reabilitação da região com enxerto ósseo liofilizado, além da instalação de uma placa de reconstrução na base da mandíbula do sistema 2.4 mm. Considerações finais: É necessário ter conhecimento sobre as lesões de aspecto radiográfico misto, que podem fazer diagnóstico diferencial com o FO, para que possa ser realizada uma correta intervenção, visto que para cada lesão há uma abordagem diferente.(AU)

The ossifying fibroma (FO) is a benign fibro-osseous neoplasm of the craniofacial region of odontogenic origin, formed from multipotent mesenchymal cells of the periodontal ligament, which are capable of forming bone, fibrous tissue and cementum. It is believed that previous exodontia, infections, trauma or a disturbance of congenital origin in bone maturation could serve as predisposing factors for FO development. Radiographically, the initial FO lesions are represented by a radiolucent, unilocular, round or oval image with well circumscribed margin. In the late stage, the mineralized component is surrounded by a thin fibrous capsule represented by a thin radiolucent line, which surrounds the entire lesion. The objective of this work is to discuss the surgical approach of a FO located in the atypical region of the mandible. Case report: leucoderma patient, 18 years, female, it were possible to note a slight volume increase in the posterior mandible region. The imaging examination identified a mixed lesion, well defined, however non-corticalised, measuring about 3 cm x 2.5 cm. The patient was submitted to an incisional biopsy and the diagnosis of ossifying fibroma was confirmed. We opted for a curettage followed by a peripheral osteotomy of the lesion and rehabilitation of the region with lyophilized bovine bone graft, besides the installation of a rebuilding plate at the base of the mandible system 2.4mm. Final considerations: it is necessary to have knowledge about lesions of mixed radiographic appearance, which can make differential diagnosis with FO so that a correct intervention can be performed, since for each lesion we have a different approach.(AU)

Canalis Sinuosos mimetizando reabsorção radicular: relato de caso / Canalis sinuosus mimicking root resorption: case report

Relato de caso: Relatar um caso de canal acessório do Canalis Sinuosos, localizado por palatino à raiz do dente 21 que, na radiografia panorâmica, foi observada como uma área radiolúcida sobreposta aos terços médio-apical dente 21, indicando reabsorção radicular, sendo indispensável uma investigação acurada por tomografia computadorizada de feixe cônico (TCFC). Conclusão: A TCFC se mostrou eficiente na identificação do Canalis Sinuosos em relação à radiografia panorâmica, possibilitando um correto diagnóstico para o caso.

Case report: This report describes a case of Canalis sinuosus accessory canal, lingually to the root of the tooth 21, that was observed on panoramic radiograph as a radiolucent area superimposed over the middle and apical thirds, indicating root resorption. However, cone-beam computed tomography (CBCT) recommended for an accurated diagnosis of the case disclose the presence of this anatomic variation. Conclusion: CBCT was more accurate in detection of Canalis sinuosus than panoramic radiography.

Assessment of condyle position, fossa morphology, and disk displacement in symptomatic patients.

OBJECTIVE: The aim of the study was to determine whether there are any associations between the morphology of the glenoid fossa, articular spaces, and disk displacement by evaluating the magnetic resonance imaging (MRI) scans of symptomatic patients. Gender and age were also evaluated for any effect on the parameters. STUDY DESIGN: MRI scans of 199 temporomandibular joints were assessed for the morphology of the glenoid fossa and articular spaces in both sagittal and coronal views. The presence of disk displacement and its type in closed-mouth and open-mouth positions were also assessed. Analysis of variance (ANOVA), Tukey, and Student t tests or Mann-Whitney rank sum tests were used to investigate the associations among these variables. RESULTS: A total of 113 joints (56.8%) were presented with disk displacement. The articular spaces observed in sagittal and coronal views were, overall, significantly larger in males than in females in 3 of the 6 spaces (superior, posterior, and central spaces). Larger superior and medial articular spaces were associated with angled glenoid fossae. Higher mean values of the articular space sizes were associated with normal disk position (P < .001), except for the anterior articular space. When displacement was identified, higher values of the articular space sizes were also associated with disk reduction in the open-mouth position (P < .05). CONCLUSIONS: Condyles in the central position in the coronal view and slightly anteriorly positioned in the sagittal view are less likely to present disk displacement.

Skeletal stability in orthognathic surgery: evaluation of methods of rigid internal fixation after counterclockwise rotation in patients with class II deformities.

Our aim was to assess the influence of internal fixation in skeletal stability on patients who had had counterclockwise rotation of the maxillomandibular complex and mandibular advancement procedures. We studied 60 records of 20 patients (14 female, 6 male), mean (range) age at operation 29 (16-50) years. The mean (range) postoperative follow-up was 15 (8-24) months. Sixty standard lateral cephalometric radiographs were randomly traced and digitised by one senior radiologist to estimate surgical and postoperative changes. Patients were divided into two groups, the first group (n=10) of which had fixation with only 2.0 system plates (2 plates with monocortical screws alone) and the second (n=10) of which had hybrid fixation (1 plate with monocortical screws and 2 or 3 bicortical bone screws). During operation the change in the mean occlusal plane with counterclockwise rotation was 9.4° (range -17.3 to -2.5mm). The maxilla moved forward and upward. All the anterior mandibular measurements had advanced horizontally, the mean (range) being 17 (6.4 to 9.9) mm for the pogonion, and 17.6 (6.0 to 30.7) mm for the menton. At the longest follow-up period, there were significant long-term changes, but these were clinically acceptable (<2mm). There was no significant difference between the two groups in postoperative stability or in the magnitude of the advancement and stability.

Canal incisivo mandibular em pacientes edêntulos: análise na radiografia panorâmica digital / Mandibular incisive canal in edentulous patients: analysis by means of digitalpanoramic radiography

O objetivo desse trabalho foi avaliar, radiograficamente, a região entre osforames mentonianos quanto à presença e características do canal incisivo mandibular, um importantereparo associado a complicações pós-operatórias das cirurgias de instalação de implantesosseointegráveis. Material e Métodos: cinquenta e dois pacientes edêntulos, atendidos em um períodode doze meses, na Clínica de Prótese Total da Faculdade de Odontologia da Universidade Federalda Bahia, foram submetidos ao exame panorâmico digital. As imagens foram avaliadas por umúnico radiologista e a presença do canal incisivo mandibular, bem como seu comprimento, formatoda trajetória e distâncias em relação à crista óssea alveolar e base mandibular foram registrados.Resultados: a amostra final consistiu de 49 exames. O canal incisivo mandibular foi visualizado emoito radiografias, representando 16,3% da população investigada, com variação de 10,7 a 19,7mmde comprimento. A ocorrência bilateral foi mais frequente (50%), bem como a trajetória horizontal(5 casos). Consideração final: a presença e anatomia intraóssea do canal incisivo mandibularnão devem ser ignoradas no planejamento cirúrgico envolvendo a região anterior da mandíbula.Isso se torna fundamental para evitar intercorrências transoperatórias e também para prevenira ocorrência de distúrbios sensoriais e hemorrágicos no período pós-operatório...

The aim of this study was to radiographically assess the region betweenthe mental foramina for the presence and characteristics of mandibular incisive canal, a major repairassociated with postoperative complications of osseointegrated implant placement surgeries.Material and Methods: Fifty-two edentulous patients treated during twelve months in the DentalClinics of the Federal University of Bahia underwent digital panoramic examination. The imageswere evaluated by a single radiologist and the presence of the mandibular incisive canal, its length,the shape of its trajectory and the distances from the alveolar crest and mandibular base were recorded.Results: The final sample consisted of 49 exams. Mandibular incisive canal was observedin eight radiographs, and accounted for 16.3% of the population investigated, with length varyingfrom 10.7 to 19.7 mm. Bilateral lesions were more frequent (50%), and so was the horizontal path(5 cases). Final consideration: The presence and intraosseous anatomy of mandibular incisive canalshould not be ignored in surgical planning involving the anterior mandible region. This becomes critical to prevent perioperative complications and also to prevent the occurrence of sensory and bleeding disorders in the postoperative period...

Evaluation of buccal bone coverage in the anterior region by cone-beam computed tomography.

INTRODUCTION: The purpose of this study was to compare the sensitivity of diagnoses of buccal bone coverage in anterior teeth between axial and sagittal reconstructions using cone-beam computed tomography. METHODS: Five dry skulls were clinically evaluated to detect bone defects in the anterior maxilla and mandible to establish a gold standard. The skulls were prepared and placed on a Kodak 9000 3-dimensional scanner (Trophy, Marne La Vallée, France) for image acquisition. The images were processed and reconstructed using Kodak Dental Imaging software 3-dimensional module (version 2.4; Kodak Dental Systems, Atlanta, Ga). All bone defects were identified and recorded. RESULTS: In the sagittal and axial reconstructions, regions without bone coverage were diagnosed in 91.03% of cases as "cortex not seen" or "minimum thickness, fine, without marrow bone." CONCLUSIONS: Cone-beam computed tomography can help in the diagnosis of lack of bone coverage on the buccal surfaces of anterior teeth. There was no difference in the performance of the axial and sagittal reconstructions.

Hiperpneumatização do processo mastóide do osso temporal: relato de caso / Hyperpneumatization of mastoid process of temporal bone: report of a case

O presente trabalho apresenta um caso de hiperpneumatização do osso temporal detectado em uma paciente do sexo feminino, 23 anos, saudßvel, que compareceu a clínica de Radiologia para um exame radiogrßfico de rotina. A radiografia panorâmica revelou imagens radiolúcidas bilaterais envolvendo a região correspondente às eminências articulares. Exames tomogrßficos convencional e computadorizado foram solicitados, adicionalmente, com objetivo de confirmação diagnóstica da hiperpneumatização. Um ano após o exame inicial, foi realizada nova tomada radiogrßfica panorâmica, que revelou estabilidade dimensional das imagens.

Anquilose em dentes decíduos / Ankylosis of primary teeth

Considerada como anomalia de irrupção dentária, a anquilose dentoalveolar em dentes decíduos é um dos fatores etiológicos da maloclusão. O diagnóstico precoce e a conduta a ser adotada frente a este quadro gera algumas controvérsias por parte dos profissionais. Por conseguinte, abordando estes aspectos, os autores sugerem uma seqüência de critérios e procedimentos baseados na análise clínica e radiográfica do dente decíduo anquilosado e seu sucessor permanente

Cavidade óssea de Stafne: relato de casos / Stafne's bone cavity: report of cases

Este trabalho aborda dois casos clínicos de cavidade óssea de Stafne. O primeiro caso, assintomático, refere-se a indivíduo de 68 anos, sexo masculino, cuja lesäo foi descoberta através de radiografia panorâmica de rotina. O segundo caso, também assintomático, relaciona-se a lesäo descoberta através de um exame radiográfico periapical da boca completa, em indivíduo de 49 anos, sexo feminino. A tomografia computadorizada mostrou-se definitiva näo só no diagnóstico conclusivo da condiçäo, mas também na sua classificaçäo

Côndilo mandibular bífido: relato de caso / Bifid mandibular condyle: report of a case

E relatado um caso de côndilo mandibular bífido, descoberto através de radiografia panorâmica de rotina, envolvendo paciente do sexo masculino, de 77 anos, e localizado no lado esquerdo. O paciente não relatou sintomatologia, história de trauma ou sinais de disfunção temporo-mandibular