Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
1.
Braz. oral res. (Online) ; 29(1): 1-6, 2015. tab, ilus
Article in English | LILACS | ID: lil-777179

ABSTRACT

The purpose of this study was to analyze four different cone-beam computed tomography (CBCT) protocols to identify horizontal root fractures (HRF) in endodontically treated teeth, with or without the presence of a metallic post. Thirty extracted single-rooted human premolars were treated endodontically. Afterwards, an observer induced a horizontal fracture in 15 teeth. Each tooth was inserted in an empty mandibular socket and submitted to a computed tomography scan taken with and without the metallic post. The acquisition followed four different protocols, with different fields of view (FOV) and voxel sizes, as follows: FOV 6X16 cm/0.2 mm voxel; FOV 6X16 cm/0.25 mm voxel; FOV 8X8 cm/0.2 mm voxel; FOV 8X8 cm/0.25 mm voxel. Two observers checked all the acquisitions within a two-week interval, and the values of sensitivity, specificity, accuracy and kappa were calculated. The sensitivity, specificity and accuracy values were better for the 8X8 cm/0.2 mm and 16X6 cm/0.25 mm protocols, ranging from 0.60 to 0.86 and 0.53 to 0.80, respectively. The intra- and interobserver concordance ranged from 0.65 to 0.72. The protocols where FOV and voxel were proportional showed better results. The 8x8 cm/0.2 mm protocol had the least interference from the metallic artifact. All four protocols showed a decline in values in the presence of the metallic artifact.


Subject(s)
Humans , Cone-Beam Computed Tomography/methods , Tooth Fractures , Tooth Root/injuries , Tooth, Nonvital , Bicuspid , Observer Variation , Reference Values , Reproducibility of Results , Sensitivity and Specificity , Time Factors , Tooth Root
2.
Braz. oral res. (Online) ; 29(1): 1-7, 2015. tab, ilus
Article in English | LILACS | ID: lil-777166

ABSTRACT

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.


Subject(s)
Animals , Periapical Diseases/diagnostic imaging , Cone-Beam Computed Tomography/methods , Maxillary Sinus/diagnostic imaging , Reference Values , Swine , Time Factors , Image Processing, Computer-Assisted/methods , Maxillary Sinusitis/diagnostic imaging , Observer Variation , Predictive Value of Tests , Reproducibility of Results , Sensitivity and Specificity , Radiography, Dental, Digital/methods , Models, Animal
3.
Braz. oral res ; 27(2): 128-135, Mar-Apr/2013. tab, graf
Article in English | LILACS | ID: lil-668003

ABSTRACT

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.


Subject(s)
Female , Humans , Male , Cone-Beam Computed Tomography/methods , Imaging, Three-Dimensional/methods , Mandible , Software , Anatomy, Cross-Sectional , Mandible/anatomy & histology , Observer Variation , Organ Size , Radiographic Image Interpretation, Computer-Assisted , Reproducibility of Results
4.
São Paulo; s.n; 2013. 56 p. ilus, tab. (BR).
Thesis in Portuguese | LILACS, BBO | ID: biblio-866983

ABSTRACT

A detecção de periapicopatias comprometendo a cortical sinusal pode ser subestimada em radiografias periapicais, que é o exame de rotina, pela sobreposição de estruturas. Neste estudo, a sensibilidade, especificidade e reprodutibilidade da TCFC para a avaliação da integridade da cortical sinusal próxima de lesões periapicais (com e sem comunicação oroantral) foram avaliadas em relação a um padrão-ouro (erosões na região periapical de molares superiores em 20 maxilas suínas maceradas). Foi realizada a primeira etapa de aquisições com as maxilas íntegras, visando familiarizar os observadores com a anatomia da maxila suína e excluir da amostra os sítios com defeitos ósseos pré-existentes. Após isso, foram extraídos os primeiros-molares e lesões periapicais foram simuladas com ácido perclórico. A duração da exposição ao ácido foi controlada em dois tempos: T1 que gerou lesões incipientes e T2 que gerou lesões maiores. O estabelecimento de comunicação oroantral deu-se em 22 sítios. Em seguida, os dentes foram reimplantados nos devidos alvéolos. Realizou-se a segunda etapa de aquisições. Dois observadores, devidamente familiarizados com lesões simuladas na maxila suína com e sem comunicação, avaliaram os exames duas vezes, com intervalo de tempo de uma semana. Todos os exames estavam em ordem aleatória em uma estação de trabalho independente contendo o software OsiriX MD. Os resultados demonstraram uma boa acurácia (66 a 78%) e alta especificidade (70 a 98%) com índices moderados de concordância intraobservadores (0,49 e 0,56), porém gerou resultados distintos de sensibilidade (41%, 55%, 78% e 60%) que culminou em um baixo índice de concordância interexaminadores (0,21 e 0,35). A maior dificuldade relatada pelos observadores foi a alta presença de ruído na imagem, influenciada principalmente pela relação do FOV e voxel que acabou afetando a resolução da imagem do exame.


The detection of periapical diseases affecting the cortical sinus may be underestimated in periapical radiographs, which is the method of choice, by overlapping structures. In this study, the sensitivity, specificity and reproducibility of CBCT to assessing the integrity of the cortical sinus near periapical lesions (with and without communication oroantral) were evaluated by comparing with a gold standard (erosions in the periapical region of maxillary molars in 20 maxillae swine macerated). We performed the first step of acquisitions with intact maxillae in order to acquaint the observers with the swine anatomy and delete the sample sites with pre - existing bone defects. After this, we extracted the first premolar and simulated periapical lesions with perchloric acid . The duration of acid exposure was controlled in two stages: generating incipient lesions T1 and T2 which generated larger lesions. Establishing oroantral communication was more related to the proximity with the alveolus then the periapical periodontitis size, generating 22 sites with communication. Then the teeth were reimplanted in the appropriate dental alveoli to the next tomographic acquisitions. Two trained observers evaluated the tests twice, with an interval of a week's time. All tests were in random order on a standalone workstation with software OsiriX MD. The results demonstrated good accuracy (66 to 78%) and high specificity (70% to 98%) and moderate rate of intraobserver concordance (0,49 and 0,56)trai, but generated different results of sensitivity (41%, 55%, 78% and 60%) which culminated in a low rate of interobserver concordance (0,35 and 0,21). The main difficulty reported by the observers was the high presence of image noise, mainly influenced by the ratio of the FOV and voxel that ended up affecting the reliability of the examination.


Subject(s)
Maxillary Sinus , Periapical Periodontitis/diagnosis , Sinusitis/diagnosis , Tomography, Emission-Computed
SELECTION OF CITATIONS
SEARCH DETAIL