Resumo Objetivos: Avaliar a anatomia do ducto nasolacrimal e a espessura do osso maxilar adjacente por meio de tomografia computadorizada multislice. Métodos: Imagens tomográficas de 92 indivíduos (184 lados) foram analisadas quanto ao sexo, lado e padrão esquelético sagital (Classe I, II e III) e vertical (mesocefálico, braquicefálico e dolicocéfalo). Os maiores diâmetros do ducto nasolacrimal e espessura do osso maxilar adjacente foram medidos quando a sutura lacrimomaxilar estava completamente visível. Além disso, as medidas foram realizadas 2 mm acima e abaixo do ponto médio. As medidas do osso maxilar e do ducto nasolacrimal foram analisadas por ANOVA de uma via com teste post hoc de Tukey. Resultados: Indivíduos do sexo feminino apresentaram ducto lacrimal significativamente mais estreito no ponto médio (p=0,026) e 2 mm acima (p=0,025). A espessura óssea maxilar foi maior nos indivíduos Classe II em comparação aos indivíduos Classe I no ponto médio (p=0,012) e 2 mm acima (p=0,027). O grupo dolicocefálico apresentou maior espessura óssea maxilar no ponto médio (p=0,014) e 2 mm abaixo (p=0,005) quando comparado ao grupo braquicefálico. A espessura óssea maxilar foi maior em indivíduos mesocefálicos em comparação com indivíduos dolicocéfalos (p=0,04). Conclusões: Indivíduos braquicefálicos Classe I apresentam menor espessura óssea maxilar adjacente ao ducto nasolacrimal, facto que aumenta o risco de lesão durante o processo de fixação óssea.

Abstract Objectives: To evaluate the anatomy of the nasolacrimal duct and the adjacent maxillary bone thickness using multislice computed tomography. Methods: Tomographic images of 92 individuals (184 sides) were analyzed according to sex, side, and sagittal (Class I, II, and III) and vertical (mesocephalic, brachycephalic, and dolichocephalic) skeletal patterns. The largest diameters of the nasolacrimal duct and the thickness of the adjacent maxillary bone were measured when the lacrimomaxillary suture was completely visible. In addition, the measurements were performed 2 mm above and below the midpoint. The maxillary bone and nasolacrimal duct measurements were analyzed by one-way ANOVA with Tukey’s post-hoc test. Results: Females had a significantly narrower lacrimal duct at the midpoint (p=0.026) and 2 mm above it (p=0.025). Maxillary bone thickness was greater in Class II individuals compared to Class I at the midpoint (p=0.012) and 2 mm above it (p=0.027). The dolichocephalic group had greater maxillary bone thickness at the midpoint (p=0.014) and 2 mm below it (p=0.005) compared to the brachycephalic group. Maxillary bone thickness was greater in mesocephalic individuals compared to dolichocephalic individuals (p=0.04). Conclusions: Brachycephalic Class I individuals have lower maxillary bone thickness adjacente to the nasolacrimal duct, which increases the risk of injury during the bone fixation process.

Resumo O objetivo nesse estudo foi avaliar o efeito da ferramenta de redução de artefato (FRA) na expressão de artefatos em diferentes regiões de um dente restaurado com diferentes tipos de pinos metálicos. Foram usados alvéolos (regiões anterior e posterior) de uma mandíbula e um dente unirradicular. Imagens de tomografia computadorizada de feixe cônico do dente sem pino metálico intracanal e com pinos de cobalto-cromo (Co-Cr), níquel-cromo (Ni-Cr) ou prata-paládio (Ag-Pd) foram individualmente obtidas, com 2 condições de FRA: desativada e ativada. Em uma reconstrução axial, linhas de interesse (LOIs) foram definidas ao redor do canal: 4 em direções oblíquas (mésio-vestibular, disto-vestibular, mésio-lingual e disto-lingual) e 4 em direções ortogonais (mesial, distal, vestibular e lingual). A expressão dos artefatos de endurecimento do feixe foi determinada pelo cálculo da diferença na média dos valores de cinza (DMVC) entre os grupos experimental e controle para cada LOI. Não houve diferença significativa nos valores de DMVC entre as condições “sem FRA” e “com FRA” para nenhuma das LOIs, nem na região anterior nem na região posterior da mandíbula (p>0,05), para os grupos Ni-Cr e Co-Cr. Para o Ag-Pd, diferenças significativas nos valores de DMVC foram observadas entre “sem FRA” e “com FRA” para a maioria das LOIs (p<0,05), principalmente nas direções oblíquas na região anterior, e na direção mesio-distal na região posterior. A FRA atuou principalmente em artefatos hipodensos (DMVC negativos). A eficácia da FRA disponível no aparelho de TCFC OP300 variou de acordo com o material do pino testado. Ela foi efetiva na redução da expressão de artefatos originados por pinos de Ag-Pd, principalmente nas regiões do dente afetadas por artefatos hipodensos, independentemente da região mandibular.

Abstract This study aimed to assess the effect of the MAR tool on the expression of artefacts in different regions of a tooth restored with different types of metal posts. Alveolar sockets (anterior, and posterior region) of a mandible and an unirradicular tooth were used. Cone beam computed tomography scans of the tooth without a metal post, and with cobalt-chromium (Co-Cr), nickel-chromium (Ni-Cr), or silver-palladium (Ag-Pd) were individually obtained, with 2 MAR conditions: disabled, and enabled. In an axial reconstruction, lines of interest (LOIs) were set around the canal: 4 in oblique (mesiobuccal, distobuccal, mesiolingual, distolingual) directions, and 4 in orthogonal (mesial, distal, buccal, lingual) directions. Beam-hardening artefacts expression was determined by calculating the difference in the mean of gray values (DMGV) between the experimental and control groups for each LOI. There was no significant difference in the DMGV values between “without MAR” and “with MAR” for any LOI, in neither anterior nor posterior mandible (p>0.05), for the Ni-Cr and Co-Cr groups. For the Ag-Pd, significant differences in the DMGV values were observed between “without MAR” and “with MAR” for most LOIs (p<0.05), mainly in oblique directions in the anterior region, and mesio-distal direction in the posterior region. MAR acted mostly in hypodense artefacts (negative DMGV). The effectiveness of the MAR tool of the OP300 CBCT unit varied according to the post material tested. It was effective in reducing the expression of artefacts raised by the Ag-Pd post, mainly in the tooth regions affected by hypodense artefacts, regardless of the mandibular region.

RESUMO Objetivo: O presente estudo teve como objetivo investigar a relação entre a inclinação dentária e as dimensões ósseas e gengivais em dentes anteriores superiores. Métodos: Esse estudo transversal incluiu imagens de tomografia computadorizada de feixe cônico (TCFC) de 160 dentes anteriores superiores divididos em três grupos (incisivo central, incisivo lateral e canino). Todos os pacientes tinham 18 anos ou mais, não tinham tratamento ortodôntico prévio nem história clínica que pudesse afetar as dimensões ósseas ou gengivais. A inclinação dentária, a espessura do osso e da gengiva e as distâncias da junção cemento-esmalte à crista óssea alveolar e à margem gengival foram medidas na face vestibular. As correlações foram analisadas por meio dos testes de Pearson e de correlação parcial (p≤0,05). Resultados: Nos incisivos centrais, a inclinação dentária foi positiva e significativamente relacionada à espessura do osso apical (R = 0,34, p= 0,001). Nos caninos, a inclinação dentária foi negativa e significativamente relacionada à espessura do osso cervical (R = - 0,34, p= 0,01) e positivamente associada à espessura do osso apical (R = 0,36, p= 0,01) e à distância entre a margem gengival e a junção cemento-esmalte (R = 0,31, p= 0,03). Nos incisivos laterais, a inclinação do dente não foi associada às dimensões do osso ou da gengiva. Conclusões: Nos incisivos centrais, quanto maior a inclinação vestibular do dente, maior a espessura do osso apical. Nos caninos, quanto maior a inclinação vestibular do dente, menor a espessura do osso cervical, maior a espessura do osso apical e maior a margem gengival. As dimensões ósseas e gengivais devem ser avaliadas ao se planejar o tratamento ortodôntico envolvendo a movimentação vestibular dos incisivos centrais e caninos.

ABSTRACT Objective: The present study aimed to investigate the relationship between tooth inclination and gingival and bone dimensions in maxillary anterior teeth. Methods: This cross-sectional study included cone-beam computed tomography (CBCT) images of 160 maxillary anterior teeth (30 individuals). Tooth inclination, gingival and bone thickness, and distances from cementoenamel junction to alveolar bone crest and gingival margin were measured in the labial surface. The correlations were analyzed using Pearson and partial correlation tests (p≤0.05). Results: In the central incisors, tooth inclination was positively and significantly related to apical bone thickness (R = 0.34, p= 0.001). In the canines, tooth inclination was negatively and significantly related to cervical bone thickness (R = - 0.34, p= 0.01) and positively associated to apical bone thickness (R = 0.36, p= 0.01) and to gingival margin-cementoenamel junction distance (R = 0.31, p= 0.03). In the lateral incisors, tooth inclination was not associated with gingival or bone dimensions. Conclusions: In the central incisors, the greater the labial tooth inclination, the greater is the apical bone thickness. In the canines, the greater the labial tooth inclination, the smallest is the cervical bone thickness, the greater is the apical bone thickness, and the greater is the gingival margin. Gingival and bone dimensions should be assessed when planning orthodontic treatment involving buccal movement of central incisors and canines.

This article aimed at comparing the accuracy of linear measurement tools of different commercial software packages. Eight fully edentulous dry mandibles were selected for this study. Incisor, canine, premolar, first molar and second molar regions were selected. Cone beam computed tomography (CBCT) images were obtained with i-CAT Next Generation. Linear bone measurements were performed by one observer on the cross-sectional images using three different software packages: XoranCat®, OnDemand3D® and KDIS3D®, all able to assess DICOM images. In addition, 25% of the sample was reevaluated for the purpose of reproducibility. The mandibles were sectioned to obtain the gold standard for each region. Intraclass coefficients (ICC) were calculated to examine the agreement between the two periods of evaluation; the one-way analysis of variance performed with the post-hoc Dunnett test was used to compare each of the software-derived measurements with the gold standard. The ICC values were excellent for all software packages. The least difference between the software-derived measurements and the gold standard was obtained with the OnDemand3D and KDIS3D (-0.11 and -0.14 mm, respectively), and the greatest, with the XoranCAT (+0.25 mm). However, there was no statistical significant difference between the measurements obtained with the different software packages and the gold standard (p> 0.05). In conclusion, linear bone measurements were not influenced by the software package used to reconstruct the image from CBCT DICOM data.

AIM:To assess which slice inclination would be more accurate in measuring sites for implant placement: the oblique or the orthoradial slice.METHODS: Five regions of eight edentulous mandibles were selected (incisor, canine, premolar, first molar and second molar). The mandibles were scanned with a Next Generation i-CAT CBCT unit. Two previously calibrated oral radiologists performed vertical measurements in all the selected regions using both the oblique and orthoradial slices. The mandibles were sectioned in all the evaluated regions in order to obtain the gold standard. The Wilcoxon signed rank test compared the measurements obtained in the oblique and orthoradial slices with the gold standard.RESULTS:The bone height measurements for the first and second molar regions using the orthoradial slices were statistically different from the gold standard.CONCLUSIONS: Using the orthoradial slices to obtain cross-sectional images may offer insufficient accuracy for implant placement in the posterior region.

AIM: To compare panoramic radiography and cone beam computed tomography (CBCT) in the diagnosis of bifid mandibular condyle. METHODS: The sample consisted of 350 individuals who underwent panoramic radiography and CBCT. In the panoramic radiographs and CBCT images, the presence or absence of bifid mandibular condyle was determined. RESULTS: Presence of bifid mandibular condyle was detected in four cases (1.1%). In all cases, the relation of one condylar process to the other was mediolateral and history of trauma was reported. None of the individuals had symptoms. In two cases, panoramic radiography did not reveal the presence of bifid mandibular condyle. CONCLUSIONS: Initial screening for bifid mandibular condyle can be performed by panoramic radiography; however, CBCT images can reveal morphological changes and the exact orientation of the condyle heads.

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.

The aim of this study was to investigate the prevalence of supernumerary teeth in a Brazilian pediatric population. One examiner evaluated the presence of supernumerary teeth in panoramic radiographs of 1719 subjects (762 male and 957 female), with ages ranging from 4 to 14.5 years (mean 8.4 years old), from the archive of the Preventive Orthodontic Course of the Rehabilitation Hospital of Bauru, São Paulo. Supernumerary teeth were present in thirty subjects (1.7%, 16 males and 14 females). Difference between sexes was not statistically significant. Twenty-nine supernumerary teeth (96.7%) were located in the maxilla, and only 1 (3.3%) located in mandible. Seventeen supernumerary teeth (56.7%) located in maxilla were mesiodens. The early diagnosis of supernumerary teeth is essential to prevent malocclusion and malposition of permanent teeth demonstrating the importance of panoramic radiographs in their detection.

El objetivo de este estudio fue investigar la prevalencia de dientes supernumerarios en una población pediátrica de Brasil. Un examinador evaluó la presencia de dientes supernumerarios en radiografías panorámicas de 1719 sujetos (762 hombres y 957 mujeres), con edades comprendidas entre 4 y 14,5 años (media 8,4 años de edad), del archivo del Curso de Ortodoncia Preventiva del Hospital de Rehabilitación de Bauru, São Paulo. Los dientes supernumerarios se presentaron en treinta sujetos (1,7%, 16 hombres y 14 mujeres). La diferencia entre sexos no fue estadísticamente significativa. Veintinueve dientes supernumerarios (96,7%) se ubicaron en el maxilar, y sólo 1 (3,3%) se ubicó en la mandíbula. Diecisiete dientes supernumerarios (56,7%) ubicados en el maxilar eran mesiodens. El diagnóstico precoz de los dientes supernumerarios es esencial para prevenir la maloclusión y malposición de los dientes permanentes, lo que demuestra la importancia de la radiografía panorámica en su detección.