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.

Condyle Excursion Angle, Articular Eminence Inclination, and Temporomandibular Joint Morphologic Relations With Disc Displacement.

PURPOSE: The aim of this study was to evaluate the relations of the condyle excursion angle (CEA) and the morphology and morphometry of the articular eminence to disc displacement (DD) using magnetic resonance imaging (MRI) of symptomatic patients. MATERIALS AND METHODS: MRIs of 199 temporomandibular joints (TMJs) were evaluated. Qualitative and quantitative morphologic analyses were performed with tools available in PACS 11.0 (Carestream Health, Inc, Rochester, NY). The articular eminence inclination (AEI), eminence height (EH), CEA, and articular eminence morphologic shape were evaluated. Statistical analyses were used to evaluate any possible association of the variables with DD in the closed- and open-mouth positions, age, and gender. The significance level was set at .05. RESULTS: Elderly women (>60 yr) presented higher prevalence values (43.26%). There was no statistical correlation between DD and gender (P = .4290). Higher mean values of the AEI and EH were associated with box-shaped eminences. The EH, AEI, and CEA were not related to the presence or absence of DD and the different types of DD. The AEI (P = .002) and CEA (P < .001) values were higher for TMJs with disc reduction in the open-mouth position. CONCLUSION: Disc position in the closed- and open-mouth positions is not influenced by articular eminence morphology; however, the AEI and CEA have an influence on disc reduction.

Morphometric features of the mandibular condyle and association with disk abnormalities.

OBJECTIVE: The aim of this study was to evaluate the relationship between the morphometric characteristics of the condyle and temporomandibular joint (TMJ) disk displacement. STUDY DESIGN: One hundred and nine individuals who underwent magnetic resonance imaging of the TMJ were evaluated. Linear (D1: condyle width; D2: condyle thickness) and angular (A1: horizontal condylar angle; A2: anterior condylar angle; A3: medial condylar angle) measurements were made. These measurements were associated with articular disk displacement, with and without reduction. RESULTS: There was statistically significant association between limited D1 and D2 and between A1 above and A1 below the mean and displacement of the joint disk. There was statistically significant association between A2 and anterior displacement of the disk. Furthermore, thicker condyles and/or condyles with smaller horizontal angles and/or with smaller medial angles were associated with articular disk reduction. CONCLUSIONS: The morphometric characteristics of the bony components of the TMJ are related to articular disk displacement and with its reduction or nonreduction.

Accessory mental foramen: A rare anatomical variation detected by cone-beam computed tomography.

The mental foramen is a bilateral opening in the vestibular portion of the mandible through which nerve endings, such as the mental nerve, emerge. In general, the mental foramen is located between the lower premolars. This region is a common area for the placement of dental implants. It is very important to identify anatomical variations in presurgical imaging exams since damage to neurovascular bundles may have a direct influence on treatment success. In the hemimandible, the mental foramen normally appears as a single structure, but there are some rare reports on the presence and number of anatomical variations; these variations may include accessory foramina. The present report describes the presence of accessory mental foramina in the right mandible, as detected by cone-beam computed tomography before dental implant placement.

Branch of the canalis sinuosus: a rare anatomical variation--a case report.

The canalis sinuosus (CS) is a neurovascular canal, a branch of the infraorbital canal through which the anterior superior alveolar nerve passes. There are no studies or case reports of anatomical variations related to this canal. A rare case of anatomical variation in the CS is reported that was detected by cone beam computed tomography done in a 47-year-old female as a pre-operative workup before dental implants. In this case, in the region slightly medial to tooth 23, a wide accessory branch from the CS was observed, running an intraosseous course in the inferior and posterior direction up to a foramen located in the hard palate, slightly medial in relation to tooth 23. The location of this branching, as well as its neurovascular component, is important for dental implant planning because of its proximity to the upper teeth. Identification of neurovascular bundles is fundamental to avoid complications for the patient.

Accuracy of linear measurements in cone beam computed tomography with different voxel sizes.

OBJECTIVE: To evaluate the accuracy of linear measurements on dry mandible specimens using cone beam computed tomography (CBCT) images acquired with different voxel sizes. METHODOLOGY: Eight human dry mandibles were submitted to CBCT examination, using the i-CAT (Imaging Sciences, Inc. Hatfield, PA) device and four protocols with different voxel sizes. Tomographic slices with a more central view of the markers, placed on six sites on each mandible, were selected to perform measurements. Values obtained from direct measurements on the dry mandible after sectioning them on the preestablished sites were compared with measurements from the tomographic images and the measurement error. RESULTS: There was no statistical difference between the measurement error of the protocols (P = 0.606). The mean value of the difference between the values obtained in the images and the dry mandible was smaller than 1 mm for all the protocols. CONCLUSION: The accuracy of vertical and horizontal measurements, using CBCT (i-CAT) for the four protocols, was shown to be comparable with the measurements performed on the dry mandible.

Assessment of enamel-dentin caries lesions detection using bitewing PSP digital images.

OBJECTIVES: The aim of this study was to evaluate the detection of enamel-dentin occlusal caries using photostimulable phosphor plates. MATERIAL AND METHODS: The ability to detect enamel-dentin occlusal caries in 607 premolars and molars from 47 patients between 10 and 18 years old, referred to the School of Dentistry of the Federal University of Bahia, Brazil, was evaluated based on clinical and radiographic examinations, using the criteria proposed in a previous study. A total of 156 bitewing digital images were obtained using Digora® (Soredex Medical Systems, Helsinki, Finland) phosphor plates. The plates were scanned and the images were captured and displayed on a computer screen. Image evaluation was done using Digora® for Windows 2.1 software, Soredex®. The radiologists were allowed to use enhancement tools to obtain better visibility during scoring of the teeth based on the radiographic criteria proposed in a previous study. Descriptive analysis and chi-squared proportion tests were done at 5% significance level. RESULTS: The results of clinical examination showed a higher prevalence of teeth with a straight dark line or demineralization of the occlusal fissure (score 1) and a lower prevalence of sealed teeth (score 5). In the bitewing digital images, 47 teeth presented visible radiolucency, circumscribed, in dentin under occlusal enamel (enamel-dentin caries lesions). CONCLUSIONS: Correlating the clinical and radiographic findings, it was found that in the majority of teeth diagnosed by radiographic images as having enamel-dentin caries, no caries could be detected by clinical examination.

Assessment of enamel-dentin caries lesions detection using bitewing PSP digital images

OBJECTIVES: The aim of this study was to evaluate the detection of enamel-dentin occlusal caries using photostimulable phosphor plates. MATERIAL AND METHODS: The ability to detect enamel-dentin occlusal caries in 607 premolars and molars from 47 patients between 10 and 18 years old, referred to the School of Dentistry of the Federal University of Bahia, Brazil, was evaluated based on clinical and radiographic examinations, using the criteria proposed in a previous study. A total of 156 bitewing digital images were obtained using Digora® (Soredex Medical Systems, Helsinki, Finland) phosphor plates. The plates were scanned and the images were captured and displayed on a computer screen. Image evaluation was done using Digora® for Windows 2.1 software, Soredex®. The radiologists were allowed to use enhancement tools to obtain better visibility during scoring of the teeth based on the radiographic criteria proposed in a previous study. Descriptive analysis and chi-squared proportion tests were done at 5 percent significance level. RESULTS: The results of clinical examination showed a higher prevalence of teeth with a straight dark line or demineralization of the occlusal fissure (score 1) and a lower prevalence of sealed teeth (score 5). In the bitewing digital images, 47 teeth presented visible radiolucency, circumscribed, in dentin under occlusal enamel (enamel-dentin caries lesions). CONCLUSIONS: Correlating the clinical and radiographic findings, it was found that in the majority of teeth diagnosed by radiographic images as having enamel-dentin caries, no caries could be detected by clinical examination.

Avaliação de doses referenciais obtidas com exames de tomografia computadorizada de feixe cônico adquiridos com diferentes tamanhos de voxel / Evaluation of referential dosages obtained by Cone-Beam Computed Tomography examinations acquired with different voxel sizes

OBJETIVO: o objetivo deste estudo reside na avaliação do produto dose-área (DAP) e das doses de entrada na pele (DEP), empregando protocolos com tamanho de voxel diferente, obtidos com o aparelho de Tomografia Computadorizada de Feixe Cônico (TCFC) i-CAT, a fim de determinar melhores parâmetros baseados nos princípios da radioproteção. MÉTODOS: para medição do DEP foi utilizada uma câmara de ionização do tipo lápis, e para o DAP foi utilizado um aparelho PTW. Quatro protocolos foram testados, a saber: (1) 40 seg., voxel de 0,2mm e 46,72mAs; (2) 40 seg., voxel de 0,25mm e 46,72mAs; (3) 20 seg., voxel de 0,3mm e 23,87mAs; (4) 20 seg., voxel de 0,4mm e 23,87mAs. A quilovoltagem permaneceu constante (120KVp). RESULTADOS: detectou-se diferença estatisticamente significativa (p<0,001) entre os quatro protocolos, para os dois métodos de avaliação da dose de radiação (DAP e DEP). Na avaliação do DAP, os protocolos 2 e 3 promoveram uma diferença estatisticamente significativa, não sendo possível detectar qual dos protocolos na avaliação da DEP proporcionou esse resultado. CONCLUSÃO: DAP e DEP apresentam-se como métodos de avaliação para doses de radiação em tomografia computadorizada de feixe cônico, sendo necessários mais estudos para elucidar tal achado. O tamanho do voxel, isoladamente, não é capaz de interferir na dose de radiação em exames de TCFC (i-CAT). A dose de radiação para exames de TCFC (i-CAT) está diretamente relacionada ao tempo de exposição e à miliamperagem.

Objectives: The aim of this study was to evaluate the dose-area product (DAP) and the entrance skin dose (ESD), using protocols with different voxel sizes, obtained with i-CAT Cone-Beam Computed Tomography (CBCT), to determine the best parameters based on radioprotection principles. METHODS: A pencil-type ionization chamber was used to measure the ESD and a PTW device was used to measure the DAP. Four protocols were tested: (1) 40s, 0.2 mm voxel and 46.72 mAs; (2) 40s, 0.25 mm voxel and 46.72 mAs; (3) 20s, 0.3 mm voxel and 23.87 mAs; (4) 20s, 0.4 mm voxel and 23.87 mAs. The kilovoltage remained constant (120kVp). RESULTS: A significant statistical difference (p<0.001) was found among the four protocols for both methods of radiation dosage evaluation (DAP and ESD). For DAP evaluation, protocols 2 and 3 presented a statistically significant difference, and it was not possible to detect which of the protocols for ESD evaluation promoted this result. CONCLUSIONS: DAP and ESD are evaluation methods for radiation dose for Cone-Beam Computed Tomography, and more studies are necessary to explain such result. The voxel size alone does not affect the radiation dose in CBCT (i-CAT) examinations. The radiation dose for CBCT (i-CAT) examinations is directly related to the exposure time and milliamperes.

Acessory mental foramen: case report

Forame mentual acessório: relato de caso. Variações anatômicas associadas ao forame mentual são relativamente incomuns. Dentre tais variações, a presença de um ou mais forames mentuais acessórios tem sido relatada em raros casos. O conhecimento da sua localização em relação ao forame mentual principal é de fundamental importância na avaliação prévia de procedimentos cirúrgicos e endodônticos. Neste artigo, um caso de forame mentual acessório foi apresentado através de imagens por tomografia computadorizada, e as principais complicações relacionadas a essa variação anatômica são discutidas

Características radiográficas dos portadores de osteoporose e o papel do cirurgião-dentista no diagnóstico / Radiographic characteristics of osteoporosis and the dentist’s role in diagnosis

A osteoporose é uma doença sistêmica dos ossos, caracterizada pela diminuição da massa óssea e deterioração da microarquitetura do tecido ósseo, o que leva a um aumento da fragilidade óssea e da susceptibilidade à fratura. Suas manifestações, na cavidade oral, são caracterizadas por: reabsorção do processo alveolar, perda dentária, doença periodontal crônica destrutiva, dores relacionadas ao seio maxilar ou fraturas. O principal método de diagnóstico da osteoporose é a densitometria óssea, embora esse exame seja de difícil acesso para a população, em alguns países. Sendo assim, propõe-sea utilização de radiografias panorâmicas dentárias nessa avaliação, já que elas costumam ser procedimentos de rotina na clínica odontológica. Vários pesquisadores propuseram índices para avaliar as alterações osteoporóticas na cavidade oral, a partir de radiografias panorâmicas, como o Índice da Cortical Mandibular, o Índice Panorâmico Mandibular e a Técnica proposta por Wical e Swoope. Todas essas técnicas avaliam a região basal da mandíbula, posterior ao forame mentual, por ser uma área que preenche os requisitos para que ocorra uma menor variação inter e intra-indivíduos em relação à anatomia, forma, estrutura óssea e função. Dessa forma, os dentistas, em geral, poderiam fazer um correto encaminhamento dos pacientes para um tratamento específico, além de ter acesso à qualidade óssea do paciente, que é de grande importância no planejamento de implantes dentários.

Complicações bucais relacionadas à radioterapia de cabeça e pescoço: uma revisão de literatura / Oral complications related to the head and neck radiotheraphy: a review of the literature

O câncer de cabeça e pescoço representa, em nível mundial, 10 por cento dos tumores malignos, sendo que cerca de 40 por cento dos casos ocorrem na cavidade bucal, 25 por cento na laringe, 15 por cento na faringe, 7 por cento nas glândulas salivares e 13 por cento nos outros locais. A odontologia desempenha um papel fundamental nas diferentes fases terapêuticas contra o câncer atuando na fase que antecede a cirurgia, em que uma avaliação prévia poderá reduzir, de forma efetiva, complicações oriundas de processos infecciosos ou inflamatórios crônicos da cavidade bucal, assim como na prevenção das sequelas que ocorrem durante e após o tratamento por radioterapia e quimioterapia. O objetivo deste artigo é realizar uma revisão de literatura acerca das principais complicações bucais relacionadas à radioterapia de cabeça e pescoço, enfatizando a importância do papel do cirurgião-dentista sobre elas

Avaliação radiológica do osso alveolar periimplantar no período de cicatrização: estudos de casos através de imagem digitalizada / Radiographic evaluation of periimplantar alveolar bone during healing period-studies of cases through digital images

A avaliação radiográfica da osteointegração emprega a redução do nível de perda óssea marginal como modalidade diagnóstica reconhecida na literatura, mesmo com suas limitações. Novos testes de diagnóstico radiográfico, além de fornecerem as informações contidas nas imagens convencionais, devem permitir avaliar a qualidade e as mudanças de densidade óssea alveolar como o permite a imagem digital. Este trabalho teve como objetivo analisar radiografias periapicais pré-implante, pós-implante até 30 dias, até 60 dias e até 120 dias, digitalizadas pelo sistema DentScan DentView, através dos valores de tons de cinza das regiões adjacentes ao implante dentário, representadas pelo osso alveolar mesial, distal, apical e implante-envolvente, ao longo do período de cicatrização. Foram escaneadas pelo sistema radiografias periapicais de arquivo de sete indivíduos que receberam implantes unitários de superfície tratada. Após a leitura dos valores de tons de cinza das áreas adjacentes ao implante, os resultados apresentaram um aumento substancial em todos os sítios pós-implante no período de 30 dias. Na maioria dos sítios, ocorre uma queda desses valores no período de 60 dias e um aumento no período de 120 dias. A mensuração dos tons de cinza afigura-se boa ferramenta para o acompanhamento radiográfico durante período de cicatrização das regiões adjacentes ao implante dentário. Novos estudos, com ampliação da amostra e do período de acompanhamento, devem ser realizados para inferir padrões de osteointegração em implantes dentários.