CBCT-based evaluation of integrity of cortical sinus close to periapical lesions

The purpose of the present study was to test the applicability of cone beam computed tomography (CBCT) to evaluate the integrity of the cortical sinus close to periapical lesions. Two observers analyzed samples of 64 alveoli of first molar roots in macerated swine maxillas prepared with perchloric acid to simulate periapical lesions. The specimens were evaluated using CBCT (55-mm high and 100-mm diameter cylinder at 0.2-mm voxel resolution) for the presence of oroantral communication (OAC) caused by the simulated lesions. Sensitivity, specificity, and accuracy were calculated. Fair values were obtained for accuracy (66%-78%) and good values for specificity (70%-98%), whereas the values for sensibility showed relevant variation (41%-78%). For this reason, the interobserver agreement score was weak. CBCT proved capable of evaluating the integrity of the cortical sinus (absence of oroantral communication) when it lies close to an apical periodontitis lesion. However, the low interobserver agreement reflects the difficulty in performing diagnoses when OAC is adjacent to a periapical lesion, using the acquisition protocol adopted in this research. This could be attributed to the high level of image noise.

Assessment of open source software for CBCT in detecting additional mental foramina

The purpose of this study was to evaluate which post-processing imaging protocol would be better to analyze the additional mental foramen (AMF) in preoperative planning with cone-beam computed tomography (CBCT) exams, and to test reproducibility of measurements, using open source software (OsiriX). The software was used to detect the cases of AMF from among 58 exams for dental implant planning in edentulous mandible areas-three cases were found. The case images were submitted to qualitative analysis using 2D orthogonal MPR, 3D-MPR and 3D volume rendering protocols by two oral and maxillofacial radiologists. Quantitative analysis used the 3D-MPR protocol; the closed polygon tool measured the mental foramen (MF) and the AMF areas; the length tool measured the distance between foramina. The measurements were performed independently by the examiners, at two different times. Intra- and interexaminer agreement was assessed using the intraclass correlation coefficient. The panoramic view did not show the MF and the AMF clearly. The AMF could be detected in the parasagittal view. 2D Orthogonal MPR was effective to observe the AMF in some cases. The 3D-MPR and 3D view protocols were the most effective to locate and analyze the AMF. In conclusion, a 3D view improves visualization when anatomical points are not clearly visible. 3D-MPR was considered a more effective post-processing imaging protocol to observe foramina relationships. The high reproducibility of measurements for anatomical MF variations was established using specific tools featured in open source software for CBCT. OsiriX is realistic and recommended for preoperative planning.

Detection of simulated incipient furcation involvement by CBCT: an in vitro study using pig mandibles

The aim of the present study was to test the reproducibility, sensitivity, and specificity of cone-beam computed tomography (CBCT) in detecting incipient furcation involvement. Fifteen macerated pig mandibles, with intact second molar teeth and preserved adjacent cortical areas, were used. Simulated lesions were created in the furcation region of these teeth by applying 70% perchloric acid in up to four possible buccal/lingual sites in the right/left sides of each mandible. The mandibles were then submitted to a CBCT scan. Two blinded and calibrated experienced oral and maxillofacial radiologists interpreted the exams. Furcation involvement was also assessed in the regions without simulated lesions. CBCT showed high levels of accuracy, ranging from 78% to 88%. The variations in Kappa values for intra- and inter-observer agreement (0.41-0.59) were considered moderate. CBCT can be considered a reliable and accurate method for detecting incipient furcation involvement.

Avaliação do grau de paralelismo no preparo de dentes suportes obtido por três técnicas / Evaluation of parallelism degree in the tooth support preparation using three different techniques

A proposta deste estudo foi avaliar a influência de três técnicas de transferência de planos guia para boca, a influência da experiência do operador, da região (anterior e posterior), da arcada (inferior e superior) e a interação destas quanto ao preparo de planos de guia confeccionados nas faces proximais de dentes suportes para prótese parcial removível. Foram instruídos 10 operadores (cirurgiões dentistas), 5 com mais de 5 anos de experiência e 5 alunos do último ano de graduação da Faculdade de Odontologia de São José dos Campos, Universidade Estadual Paulista "Julio de Mesquita Filho". Cada operador utilizou três técnicas que foram: método à mão livre, método com pino guia e método com delineador intrabucal (ParalAB), em manequins simulando classe três de Kennedy. A análise estatística ANOVA e o teste de Tukey foram os métodos utilizados para a interpretação dos resultados. Concluiu-se que a técnica que empregou o delineador intrabucal ParalAB obteve melhor paralelismo, seguido pela técnica com Pino Guia e pela técnica à Mão Livre. De acordo com a metodologia aplicada, foi possível concluir que a técnica empregada na realização dos preparos de planos de guia para a boca influencia na inclinação das superfícies produzidas, e que a experiência do operador interfere no grau de paralelismo executado por qualquer técnica, exceto os resultados obtidos pela técnica com ParalAB que usou um delineador intrabucal. A arcada superior e a região anterior tiveram melhores resultados em ambos os operadores.