Tomographic evaluation of infrazygomatic crest for orthodontic anchorage in different vertical and sagittal skeletal patterns

Analysis of the anatomy of the region during preoperative planning is very important in order to minimize the risks of undesired movements in the supporting teeth or even damage to important structures such as the maxillary sinus. To the best of our knowledge, no study evaluated the relationship of these skeletal patterns with the anatomy of the infrazygomatic crest. The aim of this study was to evaluate the tomographic measurements of the infrazygomatic crest for placement of temporary anchorage devices in individuals with different vertical and sagittal skeletal patterns. The measurements were analyzed in three regions in the crest of 67 patients above the maxillary first molar: A slice in the long axis of the mesiobuccal root, a slice passing through the center of the furcation area of the tooth, and another slice in the long axis of the distobuccal root. In each of these slices five measurements of the thickness of the infrazygomatic crest were performed, with a difference of 1 mm between them. The sagittal skeletal pattern was determined by the ANB angle and the vertical skeletal pattern by the SN.GoGn angle. The bone thickness of the crest tended to decrease gradually in the apical direction. There was no difference between different vertical and sagittal skeletal patterns. The individual parameters did not have significant influence in the thickness of the infrazygomatic crest

Avaliação da relação entre o ângulo horizontal do côndilo e o desarranjo interno da ATM, por meio de ressonância magnética

This research aimed at assessing the relation between the horizontal condylar angle (HCA) and the internal derangement (ID) of the temporomandibular joint (TMJ), as a result of interference by the TMJ disk, in individuals undergoing magnetic resonance (MR) scans. The sample included a total of 144 TMJs (sagittal and coronal views) of 72 subjects, 15 of whom were male and 57 female, with ages ranging from 15 to 70. The scans were made in a Signa system (GE) model at a magnetic field magnitude of 1.5 T. Sixty-eight TMJs were found to be normal, while 46 showed anterior displacement with reduction. Of these, 41 had some kind of adaptive change in the condyle, while 5 showed degenerative changes. Anterior displacement without reduction was found in 29 joints, 12 of which showed adaptative changes in the condyle, while 17 showed degenerative changes. Only one posterior displacement of the articular disk was recorded. For the TMJs in which disk displacement was found, such values achieved 24.69º on the right side, and 22.94º on the left side. Hence, it was possible for us to conclude that the HCA tends to increase in those TMJs where ID is present. For contralateral TMJs, a strong association was observed between HCA values (57.8%), state of normality (69.7%), and ID (66.7%). To corroborate such findings, a correlation between contralateral HCA values (63.31%) and the diagnosis for contralateral TMJs (68.05%) was determined. Thus, we could infer that there is a tendency between contralateral TMJs to share characteristics and conditions.Esta pesquisa teve por objetivo avaliar a relação entre o valor do ângulo horizontal do côndilo (AHC) e o desarranjo interno (DI), por interferência do disco da articulação temporomandibular (ATM), de indivíduos indicados para exame por ressonância magnética (RM). A amostra perfez um total de 144 ATMs (cortes sagital e coronal) de 72 indivíduos, na faixa etária de 15 a 70 anos, 15 do gênero masculino e 57 do gênero feminino. Os exames foram procedidos em um sistema modelo Signa (GE), magnitude de 1,5 T para o campo magnético. Sessenta e oito ATMs apresentaram uma condição de normalidade e 46 apresentaram deslocamento anterior do disco articular com redução. Dessas, 41 expressaram algum tipo de alteração adaptativa no côndilo e cinco, alterações degenerativas. Vinte e nove articulações mostraram deslocamento anterior do disco articular sem redução, sendo que 12 dessas apresentaram alterações adaptativas do côndilo e 17, alterações degenerativas. Foi registrado apenas um caso de deslocamento posterior do disco articular. O valor médio encontrado para o AHC do lado direito foi de 22,09º e para o lado esquerdo foi de 21,47º, para aquelas ATMs que se apresentaram em condições de normalidade. Para as ATMs com deslocamento de disco, esses valores foram de 24,69º para o lado direito e 22,94º para o lado esquerdo. Desse modo, foi-nos possível concluir que existe uma tendência ao aumento do AHC nas ATMs com DI. Observamos forte associação, para as ATMs contralaterais, entre os valores do AHC (57,8%), condição de normalidade (69,7%) e DI (66,7%). E, corroborando esses resultados, registramos correlação para os valores dos AHC contralaterais (63,31%) e o diagnóstico para as ATMs contralaterais (68,05%). Assim, pudemos inferir que existe tendência das ATMs contralaterais apresentarem as mesmas características e condições

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

Multiple Stafne Bone Defects: A Rare Entity

Stafne bone defects (SBDs) are generally located in the lingual cortex, close to the mandibular angle. We report the occurrence of multiple SBDs in an asymptomatic patient, a 60-year-old man, referred to a radiology clinic to undergo examination for the purpose of implant planning. The case of multiple SBD presented here, probably the first reported in the literature, reinforces the hypothesis that some cases of SBD may be the result of a focal failure during the ossification of the mandible

Stafne's Defect with Buccal Cortical Expansion: A Case Report

A rare case of Stafne's bone cavity, type III-G, is reported in a 49-year-old male patient who had been referred to a private clinic for a routine evaluation. The final diagnosis was based on computed tomography. Scintigraphy played a fundamental role in determining the most likely etiology

VALE UTILIZAR FILTROS NO DIAGNÓSTICO RADIOGRÁFICO DE CÁRIE INCIPIENTE?

Introdução: A doença cárie suscita diversos estudos acerca de seu diagnóstico, tratamento e prevenção e, dentre esta, as cáries incipientes representam um desafio ainda maior ao diagnóstico. Objetivo: Avaliar o diagnóstico de cárie em esmalte através de imagem digital utilizando ferramentas de melhoramento da imagem como ajuste de brilho e contraste e filtro negativo. Materiais e Métodos: A amostra do trabalho foi composta por imagens radiográficas digitais de sessenta dentes humanos, obtidas através do sistema VistaScan Perio Plus® (Dürr Dental, BietigheimBissingen, Alemanha), estas imagens foram avaliadas por dois examinadores especialistas em três momentos distintos, primeiramente avaliaram a imagem natural, depois fizeram alterações de brilho e contraste e por fim aplicaram o filtro negativo para promover melhor acuidade visual na determinação da presença ou ausência de cáries interproximais. A aplicação dessas ferramentas se deu de forma aleatória e posteriormente os dados obtidos foram submetidos a testes estatísticos, a comparar com os dados obtidos do exame microscópico dos espécimes (padrão-ouro). Resultados: Observou-se que mais de 90% das faces onde não havia doença cárie foram corretamente identificadas, o que aponta para alta especificidade do exame no reconhecimento das faces na ausência da doença. Os valores de sensibilidade, que representa o reconhecimento de cárie, tiveram um percentual menor, variando de 0% a 9,1%. Sendo observados valores satisfatórios de acurácia, superiores a 70% em todas as avaliações. Conclusão: As ferramentas de brilho e contraste, assim como, filtro negativo apresentaram discreta colaboração ao diagnóstico de cáries em esmalte.

Assessing bone thickness in the infrazygomatic crest area aiming the orthodontic miniplates positioning: a tomographic study

ABSTRACT Introduction: Due to the increasing use of miniplates for anchorage purposes in orthodontics, it is very important to know more about infrazigomatic crest anatomy (thickness), in adult patients. Objectives: Evaluate the infrazygomatic crest region thickness, in adult (male and female) patients. Methods: Cone-beam computerized tomography (CBCT) images from 40 patients were used to assess cross-sectional measurements of the infrazygomatic crest region. Measurement 1 considered thickness 2 mm above the distobuccal root of the permanent maxillary first molar, while measurement 2 was taken 2 mm above the first measurement. Results: The mean thickness of the infrazygomatic crest in males was 3.55 mm for measurement 1 and 2.84 mm for measurement 2, while in females these were 2.37 mm and 2.24 mm, respectively. Conclusion: The authors concluded that the overall mean thickness of the infrazygomatic crest was 2.49 mm with respect to measurement 1, and 2.29 mm for measurement 2, with no statistically significant differences between gender

Prevalência de raízes supranumerárias em pré-molares inferiores

Supernumerary roots consist of a developmental disturbance which can occur to any teeth, and knowledge about its occurrence is particularly important for the conduction of surgical or endodontic treatment of the affected tooth. In view of this reality, an attempt was made to determine the prevalence of supernumerary roots in lower premolars. The study was carried out with 200 periapical radiographs of the whole mouth, which totaled 800 teeth. This methodology was selected due to the possibility of analyzing radiographs of canines, premolars and lower molars using different ranges of horizontal angles, which enabled the identification of overlapped roots in the orthoradial incidence. The radiographs were submitted to the evaluation by an expert radiologist and the data underwent statistical analysis by means of sector graphs. The results showed that 14% (112) of the evaluated teeth presented supernumerary roots, of which 56% occurred in males and 44% in females. Concerning the eruption level, 61% were at the medium, 38% at the apical and 1% at the cervical 1/3 of the root. The most frequently affected tooth was the 1st premolar, which comprised 70% of the cases in comparison to 30% cases affecting the 2nd premolars. With regard to the type of occurrence, 67% were unilateral and 33% were bilateral while, of the latter, 82% occurred in the 1st lower premolars and 18% in the 2nd lower premolars.As raízes supranumerárias são uma alteração de desenvolvimento que pode envolver qualquer dente, e o conhecimento de sua ocorrência é particularmente importante para a realização de tratamento cirúrgico ou endodôntico da unidade afetada. Diante dessa realidade, procuramos determinar a prevalência de raízes supranumerárias em pré-molares inferiores. O estudo foi realizado com 200 exames radiográficos periapicais de toda a boca, perfazendo um total de 800 dentes. Optamos por essa metodologia devido à possibilidade de analisar radiografias de caninos, pré-molares e molares inferiores, tendo-se uma variação na angulação horizontal que permitiu a identificação de raízes sobrepostas na incidência ortorradial. As radiografias foram submetidas à avaliação de um radiologista experimentado e os dados levantados foram submetidos a tratamento estatístico através de gráfico de setores. Os resultados encontrados demonstram que 14% (112) dos dentes avaliados apresentaram raízes supranumerárias, nos quais 56% ocorreram no sexo masculino e 44% no feminino. Quanto ao nível de emergência, 61% foram no terço médio, 38% no apical e 1% no terço cervical da raiz. O dente mais envolvido foi o primeiro pré-molar, num total de 70% dos casos, contra 30% de segundos pré-molares. Em relação ao tipo de ocorrência, 67% foram unilaterais e 33% bilaterais, sendo que, desses últimos, 82% ocorreram em primeiros pré-molares e 18% nos segundos pré-molares inferiores

Measurements of the mandibular canal by multidetector computed tomography

Aim: The aim of this study was to investigate the measurements of the mandibular canal in different patterns of reabsorbed alveolar ridges, using multidetector computed tomography in order to evaluate the relationship of the mandibular canal with the cortex of the mandible remains. Methods: Central cross-sectional slice of 30 edentulous alveolar ridges in the mandibular first molar region of otherwise healthy patients using multidetector computed tomography were analyzed. Horizontal and vertical lines were performed tangent to the corticals of the mandible and mandibular canal. Fisher’s exact test, Spearman test and linear regression were used for statistical analysis. Significance level for all statistical tests was 95%. Results: The height of the mandible and the distance of mandibular canal to superior cortical in males were significantly higher when compared with females (p<0.05). When the height of the mandibular bone was correlated to the classification of edentulous jaws, significant differences were observed when comparing the three types (III, IV and V) as well as between III and IV type. Conclusions: The results of the present study show that the measurements for dental implant placement in the posterior region of the mandible are affected by the different patterns of bone resorptions. It was also demonstrated the importance of the computed tomography in the process of planning dental implant placements