Texture Analysis of Temporomandibular Joint Disc Changes Associated with Effusion Using Magnetic Resonance Images.

The purpose of this study was to identify changes in the temporomandibular joint disc affected by effusion by using texture analysis of magnetic resonance images (MRIs). METHODS: A total of 223 images of the TMJ, 42 with joint effusion and 181 without, were analyzed. Three consecutive slices were then exported to MaZda software, in which two oval ROIs (one in the anterior band and another in the intermediate zone of the joint disc) were determined in each slice and eleven texture parameters were calculated by using a gray-level co-occurrence matrix. Spearman's correlation coefficient test was used to assess the correlation between texture variables and to select variables for analysis. The Mann-Whitney test was used to compare the groups. RESULTS: The significance level was set at 5%, with the results demonstrating that there was no high correlation between the parameter directions. It was possible to observe a trend between the average parameters, in which the group with effusion always had smaller values than the group without effusion, except for the parameter measuring the difference in entropy. CONCLUSION: The trend towards lower overall values for the texture parameters suggested a different behavior between TMJ discs affected by effusion and those not affected, indicating that there may be intrinsic changes.

Deep-Learning-Based Automatic Segmentation of Parotid Gland on Computed Tomography Images.

This study aims to develop an algorithm for the automatic segmentation of the parotid gland on CT images of the head and neck using U-Net architecture and to evaluate the model's performance. In this retrospective study, a total of 30 anonymized CT volumes of the head and neck were sliced into 931 axial images of the parotid glands. Ground truth labeling was performed with the CranioCatch Annotation Tool (CranioCatch, Eskisehir, Turkey) by two oral and maxillofacial radiologists. The images were resized to 512 × 512 and split into training (80%), validation (10%), and testing (10%) subgroups. A deep convolutional neural network model was developed using U-net architecture. The automatic segmentation performance was evaluated in terms of the F1-score, precision, sensitivity, and the Area Under Curve (AUC) statistics. The threshold for a successful segmentation was determined by the intersection of over 50% of the pixels with the ground truth. The F1-score, precision, and sensitivity of the AI model in segmenting the parotid glands in the axial CT slices were found to be 1. The AUC value was 0.96. This study has shown that it is possible to use AI models based on deep learning to automatically segment the parotid gland on axial CT images.

In vivo study of cone beam computed tomography texture analysis of mandibular condyle and its correlation with gender and age.

OBJECTIVE: Texture analysis is an image processing method that aims to assess the distribution of gray-level intensity and spatial organization of the pixels in the image. The purpose of this study was to investigate whether the texture analysis applied to cone beam computed tomography (CBCT) images could detect variation in the condyle trabecular bone of individuals from different age groups and genders. METHODS: The sample consisted of imaging exams from 63 individuals divided into three groups according to age groups of 03-13, 14-24 and 25-34. For texture analysis, the MaZda® software was used to extract the following parameters: second angular momentum, contrast, correlation, sum of squares, inverse difference moment, sum entropy and entropy. Statistical analysis was performed using Mann-Whitney test for gender and Kruskal-Wallis test for age (P = 5%). RESULTS: No statistically significant differences were found between age groups for any of the parameters. Males had lower values for the parameter correlation than those of females (P < 0.05). CONCLUSION: Texture analysis proved to be useful to discriminate mandibular condyle trabecular bone between genders.

Magnetic resonance imaging texture analysis for quantitative evaluation of the mandibular condyle in juvenile idiopathic arthritis.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease that affects the joints and other organs, including the development of the former in a growing child. This study aimed to evaluate the feasibility of texture analysis (TA) based on magnetic resonance imaging (MRI) to provide biomarkers that serve to identify patients likely to progress to temporomandibular joint damage by associating JIA with age, gender and disease onset age. METHODS: The radiological database was retrospectively reviewed. A total of 45 patients were first divided into control group (23) and JIA group (22). TA was performed using grey-level co-occurrence matrix (GLCM) parameters, in which 11 textural parameters were calculated using MaZda software. These 11 parameters were ranked based on the p value obtained with ANOVA and then correlated with age, gender and disease onset age. RESULTS: Significant differences in texture parameters of condyle were demonstrated between JIA group and control group (p < 0.05). There was a progressive loss of uniformity in the grayscale pixels of MRI with an increasing age in JIA group. CONCLUSIONS: MRI TA of the condyle can make it possible to detect the alterations in bone marrow of patients with JIA and promising tool which may help the image analysis.

Magnetic resonance imaging texture analysis of the temporomandibular joint for changes in the articular disc in individuals with migraine headache / Análise de textura por ressonância magnética da articulação temporomanbibular com alterações no disco articular em individuos com cefaleia migranea

Objective: the aim of this study was to analyse the performance of the technique of texture analysis (TA) with magnetic resonance imaging (MRI) scans of temporomandibular joints (TMJs) as a tool for identification of possible changes in individuals with migraine headache (MH) by relating the findings to the presence of internal derangements. Material and Methods: thirty MRI scans of the TMJ were selected for study, of which 15 were from individuals without MH or any other type of headache (control group) and 15 from those diagnosed with migraine. T2-weighted MRI scans of the articular joints taken in closed-mouth position were used for TA. The co-occurrence matrix was used to calculate the texture parameters. Fisher's exact test was used to compare the groups for gender, disc function and disc position, whereas Mann-Whitney's test was used for other parameters. The relationship of TA with disc position and function was assessed by using logistic regression adjusted for side and group. Results: the results indicated that the MRI texture analysis of articular discs in individuals with migraine headache has the potential to determine the behaviour of disc derangements, in which high values of contrast, low values of entropy and their correlation can correspond to displacements and tendency for non-reduction of the disc in these individuals. Conclusion: the TA of articular discs in individuals with MH has the potential to determine the behaviour of disc derangements based on high values of contrast and low values of entropy (AU)

Objetivo: o objetivo deste estudo foi analisar o desempenho da técnica de análise de textura (AT) em exames de ressonância magnética (RM) das articulações temporomandibulares (ATM) como ferramenta para identificação de possíveis alterações em indivíduos com cefaléia migrânea (CM) relacionando os achados com a presença de desarranjos internos. Material e Métodos: trinta exames de RM das ATM foram selecionados para estudo, sendo 15 de indivíduos sem cefaleia migrânea ou qualquer outro tipo de cefaléia (grupo controle) e 15 diagnosticados com CM. As imagens de RM ponderadas em T2 das articulações realizadas na posição de boca fechada foram usadas para AT. A matriz de co-ocorrência foi usada para calcular os parâmetros de textura. O teste exato de Fisher foi usado para comparar os grupos quanto ao sexo, função do disco e posição do disco, enquanto o teste de Mann-Whitney foi usado para os demais parâmetros. A relação da AT com a posição e função do disco foi avaliada por meio de regressão logística ajustada para lado e grupo. Resultados: a AT por RM dos discos articulares em indivíduos com cefaleia migrânea tem o potencial de determinar o comportamento dos desarranjos discais, em que altos valores de contraste, baixos valores de entropia e sua correlação podem corresponder a deslocamentos e tendência a não redução do disco nesses indivíduos. Conclusão: a análise de textura dos discos articulares em indivíduos com CM tem potencial para determinar o comportamento dos desarranjos do disco com base em altos valores de contraste e baixos valores de entropia. (AU)

Three-Dimensional Volumetric Analysis of Frontal Ethmoidal Cells and Evaluation of Influential Factors: A Helical Computed Tomography Study.

In the present study, we aimed to assess frontal ethmoidal cells by using segmentation 3D software to establish a possible correlation between volume variation and both gender and age, as well as a relationship with Keros classification. Helical computed tomography images were obtained from 71 patients for analysis, in which the agger nasi cell, supra agger cell, supra agger frontal cell, supra bulla frontal cell, supraorbital ethmoidal cell, supra bulla cell, and frontal septal cell were identified and segmented to obtain their volume. Significant differences in volume were found for age and gender regarding agger nasi cells (p-value = 0.017), supra agger cells (p-value < 0.001), and frontal septal cells (p-value = 0.049). In the frontal septal cells, an increase of one year in age reduced the volume by 0.309, on average. According to Keros classification, the mean volumes were 10.07 and 25.64, respectively, for types II and III, both being greater than that of type I. Extracting volumetric data by using segmentation software in agger nasi cells, supra agger cells, and frontal septal cells may be useful for obtaining additional information related to age, in addition to possibly contributing to elucidating the anatomical variations in the region and an identification forensic tool.

Magnetic resonance imaging texture analysis to differentiate ameloblastoma from odontogenic keratocyst.

The differentiation between ameloblastoma (AB) and odontogenic keratocyst (OKC) is essential for the formulation of the surgical plan, especially considering the biological behavior of these two pathological entities. Therefore, developing means to increase the accuracy of the diagnostic process is extremely important for a safe treatment. The aim of this study was to use magnetic resonance imaging (MRI) based on texture analysis (TA) as an aid in differentiating AB from OKC. This study comprised 18 patients; eight patients with AB and ten with OKC. All diagnoses were determined through incisional biopsy and later through histological examination of the surgical specimen. MRI was performed using a 3 T scanner with a neurovascular coil according to a specific protocol. All images were exported to segmentation software in which the volume of interest (VOI) was determined by a radiologist, who was blind to the histopathological results. Next, the textural parameters were computed by using the MATLAB software. Spearman's correlation coefficient was used to assess the correlation between texture parameters and the selected variables. Differences in TA parameters were compared between AB and OKC by using the Mann-Whitney test. Mann-Whitney test showed a statistically significant difference between AB and OKC for the parameters entropy (P = 0.033) and sum average (P = 0.033). MRI texture analysis has the potential to discriminate between AB and OKC as a noninvasive method. MRI texture analysis can be an additional tool to differentiate ameloblastoma from odontogenic keratocyst.

Temporomandibular joint in juvenile idiopathic arthritis: magnetic resonance imaging measurements and their correlation with imaging findings.

OBJECTIVE: The aim of this study was to investigate the TMJ components in patients with juvenile idiopathic arthritis (JIA) and to compare them with a control group based on magnetic resonance imaging (MRI) measurements. METHODS: This study comprised an assessment of MRI measurements of 96 temporomandibular joints (TMJ) following classification criteria set by the International League of Associations for Rheumatology (ILAR). Three measurements were considered for study: condyle excursion angle (CEA), height of articular eminence (HAE) and inclination of articular eminence (IAE). All TMJs were assessed by linear measurements made by using the OnDemand 3D software. The comparison between the groups was performed by using Mann-Whitney's test. RESULTS: Lower measurement values were found for IAE, HAE and CEA in JIA patients (P-values < 0.001, 0.005 and < 0.001, respectively). CONCLUSION: The study showed the differences in MRI measurements between JIA patients and controls, with the former with the lowest indices.

Analysis of geometrical tomographic parameters of furcation lesions in periodontitis patients.

OBJECTIVES: This study was aimed to investigate the relationship between geometric parameters of furcation lesions - maximum area of lesion opening (MALO), angle formed between the roots (ABR), lesion volume (LV) and presence and height of infra-osseous defects (IOD) - and the success of therapy with enamel matrix derivative proteins (EMD) in patients with grade C periodontitis, using cone-beam computed tomography (CBCT). METHODS: The study consisted of two groups of patients with grade C periodontitis: control (surgery) (n = 17) and test (surgery + EMD) (n = 17). Images parameters on CBCT were recorded using OnDemand3D and ITK-SNAP software. RESULTS: Pearson's correlation coefficient demonstrated that only IOD was statistically significant in the probing depth PD (P = 0.01), with a moderate positive correlation (R = 0.59). MALO was found to be statistically significant (P = 0.03) in the test group (surgery + EMD), with moderate negative correlation (R = -0.5). CONCLUSION: The presence of infra-osseous defects and height were relevant in relation to the success of the type of treatment addressed in this study.

Cone Beam Computed Tomography Based Sex Estimation by Volume of Odontoid Process of The Second Cervical Vertebra / Estimativa sexual baseada em tomografia computadorizada de feixe cônico pelo volume do processo odontóide da segunda vértebra cervical

Objective: The aim of this study was to evaluate whether the volume of odontoid process of the second cervical vertebra on CBCT images can be used for sex estimation. Material and Methods: The volume of odontoid process on CBCT images of 138 subjects was measured. In addition, the patients were classified into five age groups. The comparisons between the groups in relation to sex and age were performed by using Mann-Whitney's test and Kruskal-Wallis' test, respectively. The ROC curve was used to assess the sensitivity and specificity of the volume to determine the sex. Results: No statistically significant difference was observed between age and volume. Males had significantly larger volumes than females. Values of volume equal to or greater than 1.254 mm3 have sensitivity of 68.2% and specificity of 68.1% to determine male sex. Conclusion: The volume of the odontoid process tends to be larger in males than in females and can be used as sex estimation (AU)

Introdução: O objetivo deste estudo foi avaliar se o volume do processo odontóide da segunda vértebra cervical em imagens de TCFC pode ser usado para estimativa do sexo. Material e Métodos: O volume do processo odontóide em imagens CBCT de 138 indivíduos foi medido. Além disso, os pacientes foram classificados em cinco faixas etárias. As comparações entre os grupos em relação ao sexo e idade foram realizadas por meio dos testes de Mann-Whitney e Kruskal-Wallis, respectivamente. A curva ROC foi utilizada para avaliar a sensibilidade e especificidade do volume para determinar o sexo. Resultados: Não foi observada diferença estatisticamente significativa entre idade e volume. Os machos tiveram volumes significativamente maiores do que as fêmeas. Valores de volume igual ou superior a 1,254 mm3 apresentam sensibilidade de 68,2% e especificidade de 68,1% para determinação do sexo masculino. Conclusão: O volume do processo odontóide tende a ser maior no sexo masculino do que no feminino e pode ser usado como estimativa do sexo. (AU)

Cone Beam Computed Tomography-Based Anatomical Assessment of the Olfactory Fossa.

This study aimed to investigate the olfactory fossa according to the Keros classification using cone beam computed tomography. This cross-sectional study analysed cone beam computed tomography images selected from a database belonging to a radiology centre. The scans of 174 healthy patients were analysed by using the Xoran software. Gender, age, and side were correlated with the Keros classification. The mean age of the 174 patients was 45.3 years. The most prevalent Keros classification was type II (65.52%), followed by type III (20.69%) and type I (13.79%). No significant differences were found between Keros classification and the variables age, right side (p value = 0.4620), and left side (p value = 0.5709). There were also no significant differences between gender and the variables right side (p value = 0.1421) and left side (p value = 0.2136). Based on these results, we suggest that cone beam computed tomography can be recommended for analysis of the anterior skull base. Keros type II was the most prevalent type in our sample.

O efeito de diferentes níveis de PH em soluções de flúor a 1, 1% na corrosão de arcos NITI / The effect of different PH levels on fluoride solutions at 1. 1% on corrosion of NITI archs

Objetivo: Determinar o pH crítico para ocorrer a corrosão de arcos NiTi em soluções de flúor a 1,1%, variando o pH de 3,5 a 7,0. Materiais e Métodos: Doze amostras com 10mm de comprimento de fio superelástico NiTi 0017 x 0025 (Abzil), obtidas do segmento distal dos arcos. As amostras foram aleatoriamente separadas e imersas dentro de recipientes contendo 40ml de seis soluções (água, soluções fluoretadas com pH: 3,5; 4,0; 4,5; 5,0; 5,5; 6,0; 6,5 e 7,0), sob uma mesa agitadora durante 90 minutos. Todas as amostras foram, então, levadas ao MEV. As imagens das amostras imersas em água e soluções fluoretadas com pH 7,0, 6,5 e 6,0 não se apresentaram diferentes, no entanto a partir da solução fluoretada com pH 5,5, as imagens superficiais apresentaram características diferentes dos grupos anteriores. Conclusão: Com base nos resultados obtidos neste estudo, o pH crítico para corrosão de arcos NiTi em soluções de flúor a 1,1% parece estar entre 6,0 e 5,5

Objective: To determine the critical pH to occur corrosion of NiTi arches in 1.1% fluoride solutions by varying the pH between 3.5 and 7.0. Materials and Methods: Twelve samples of 10 mm length superelastic NiTi wire 0017 x 0025 (Abzil) obtained in the distal segment of the arcs. The samples were randomly separated and immersed in 40 ml of six solutions (water, fluoride solutions with pH: 3.5; 4.0; 4.5; 5.0; 5.5; 6.0; 6.5 and 7.0) under a shaker table for 90 minutes. All samples were observed under SEM. The images of the samples immersed in water and fluoride solutions at pH 7.0, 6.5 and 6.0 did not show differences, however from the fluoride solution at pH 5.5, the surface characteristics of images presented differences from above groups. Conclusion: Based on the results obtained in this study the critical pH for corrosion of NiTi arches in fluoride solutions to 1.1% appears to be between 6.0 and 5.5

Espessura do esmalte interproximal e largura mesiodistal de incisivos inferiores / Mesiodistal width and proximal enamel thickness of lower incisors

Este trabalho teve como objetivo avaliar a espessura de esmalte das faces proximais dos incisivos inferiores, e comparar as mensurações da largura mesiodistal obtidas nas radiografias e nos modelos de gesso, para cada incisivo inferior. Para isso, 29 pacientes que estavam em tratamento ortodôntico tiveram os modelos de gesso e as radiografias periapicais mensuradas na largura mesiodistal, realizada com paquímetro digital na altura do ponto de contato. A espessura de esmalte também foi mensurada nas radiografias periapicais utilizando o mesmo método, nas faces mesiais e distais. Os dados foram analisados utilizando-se os testes Anova two-way e Tukey, com nível global de significância de 5%. O teste de Tukey demonstrou que os incisivos laterais inferiores (32 e 42) apresentavam largura mesiodistal maiores, quando comparados aos incisivos centrais (31 e 41). Para a espessura de esmalte nas faces proximais, não houve diferença estatística (p > 0,05) para interação dente X face proximal (p=0,953), e para o fator dente (p=0,102), no entanto, para fator face proximal demonstrou diferença estatisticamente significante (p=0,00). O teste de Tukey apontou que as faces distais apresentam maior espessura de esmalte (0,79 mm) quando comparados às faces mesiais de esmalte (0,71 mm). Pôde-se concluir que: 1) o método de mensuração da largura mesiodistal através de modelo de gesso ou de radiografias periapicais apresentam resultados estatisticamente semelhantes; 2) os dentes 32 e 42 apresentam maior largura mesiodistal do que os 31 e 41; e 3) tanto para os incisivos laterais quanto para os incisivos centrais, a face distal apresenta maior espessura de esmalte...

This study aimed to evaluate measurements the enamel thickness of the proximal surfaces in lower incisors and to compare the measurements of the average-distal width obtained on radiographs and dental casts for each incisor. Twenty-nine patients who were undergoing orthodontic treatment. Both plaster models as in periapical radiographs to measure the mesiodistal width was performed with a digital caliper at the time of the contact point. The thickness of enamel was measured on periapical radiographs using the same method, both the mesial, the distal surface of each incisor. Data were analyzed using two-way Anova and Tukey, with global significance level of 5%. The Tukey test showed that the lower lateral incisors (32 and 42) have higher mesiodistal width when compared to the central incisors (31 and 41). For the thickness of enamel in proximal faces no statistical difference (p > 0.05) for tooth X proximal face interaction (p=0.953) and for the tooth factor (p=0.102), however, compared to proximal factor showed a difference statistically significant (p=0.000). The Tukey test showed that the distal faces have thicker enamel (0.79 mm) compared to the mesial faces of enamel (0.71 mm). It can conclude that: 1) the method of measuring mesiodistal width through the plaster model or periapical radiographs are statistically similar results; 2) the tooth 32 and 42 have higher mesiodistal width of the 31 and 41; 3) for lateral incisors and central incisors, the distal face has greater thickness of enamel...