RESUMO Introdução: devido ao aumento do uso de miniplacas para ancoragem em Ortodontia, torna-se de fundamental importância compreender melhor a anatomia da crista infrazigomática (espessura) em pacientes adultos. Objetivos: avaliar a espessura da crista infrazigomática em pacientes adultos (sexos feminino e masculino). Métodos: foram utilizadas tomografias computadorizadas de feixe cônico (TCFC) de 40 pacientes, para avaliar medidas da região da crista infrazigomática, no sentido transversal. A Medida 1 verificou a espessura mm acima da raiz distovestibular do primeiro molar permanente superior, enquanto a Medida 2 foi realizada 2 mm acima da primeira medida. Resultados: a espessura média da crista infrazigomática encontrada no sexo masculino foi de 3,55 mm para a Medida 1 e de 2,84 mm para a Medida 2, e no sexo feminino foi de 2,37 mm e de 2,24 mm, respectivamente. Conclusão: os autores puderam constatar que a espessura média da crista infrazigomática foi de 2,49 mm para a Medida 1, e de 2,29 mm para a Medida 2, sem diferença estatisticamente significativa entre os sexos.

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.

The nasopalatine canal is a long slender structure present in the midline of the anterior maxilla that connects the palate to the floor of the nasal cavity. The nasopalatine canal contains the nasopalatine nerve, the terminal branch of the nasopalatine artery, fibrous connective tissue, adipose tissue, and minor salivary glands. The purpose of this article was to report a case of a trifid nasopalatine canal detected by cone beam computed tomography prior to dental implant placement. A 47-year-old female patient was submitted to cone beam computed tomography. Axial and sagittal sections revealed a trifurcation of the nasopalatine canal. Each canal was separated from the other by bony septa and extended independently from the floor of the nasal cavity to the incisive foramen in the remnant of the alveolar process in the anterior region of the maxilla. Cone beam computed tomography has permitted better visualization of the details and anatomical variations of the nasopalatine canal. Detailed knowledge of variations in the shape, number and size of the nasopalatine canal is fundamental for surgical procedures, such as local anesthesia in the anterior maxillary region and placement of dental implants, in order to prevent damage to important arteries and nerves.

El canal nasopalatino es una larga estructura delgada presente en la línea media del maxilar anterior que conecta el palato al suelo de la cavidad nasal. El canal nasopalatino contiene el nervio nasopalatino, la rama terminal de la arteria nasopalatina, el tejido conectivo fibroso, el tejido adiposo y las glándulas salivales menores. El propósito de este artículo es presentar el caso de un canal nasopalatino trifid detectado a través de tomografía computarizada de haz cónico anterior a la colocación de implantes dentales, en una paciente de femenino 47 años de edad. Secciones axiales y sagitales revelaron la trifurcación del canal nasopalatino. Cada canal se apartó del otro por tabiques ósea y extendida independientemente del suelo de la cavidad nasal para el agujero incisivo en el remanente del proceso alveolar en la región anterior del maxilar. La tomografía computarizada de haz cónico ha permitido una mejor visualización de los detalles y variaciones anatómicas del canal nasopalatino. El conocimiento detallado de las variaciones en su forma, el número y el tamaño del canal nasopalatino es fundamental para los procedimientos cirúrgicos, así como la anestesia local en la región anterior del maxilar superior y la colocación de los implantes dentales, con el fin de prevenir el daño a las arterias y a los nervios importantes.

Abstract Aim: To evaluate canal transportation and centering ability of Protaper and WaveOne systems in curved root canals by cone-beam computed tomography. Methods: Twenty human molars were randomly divided into two groups according to the system used: Group GP (ProTaper Universal(r)) and group GW (WaveOne(tm)). CT scans were performed before and after the chemo-mechanical preparation on three points: 2 mm, 3 mm and 4 mm from the tooth apex. The cuttings in dentin were measured and results were statistically analyzed. Results: In GP, there was higher percentage in transport at 2 mm and 4 mm toward the mesial wall of the tooth root compared to GW (p<0.05). There was no difference between the systems regarding their centering ability. Conclusions: None of the systems was able to touch all the dentin walls and stay centered during the chemical-mechanical preparation.

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.

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.

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.

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.