Aggressive unicystic ameloblastoma affecting the posterior mandible: late diagnosis during orthodontic treatment

Sérgio Lúcio Pereira de Castro Lopes,Isadora Luana Flores,Thiago de Oliveira Gamba,Rivea Ines Ferreira-Santos,Mari Eli Leonelli de Moraes,Aline Alvarez Cabello,Paula Nascimento Moutinho 대한구강악안면외과학회 2017 대한구강악안면외과학회지 Vol.43 No.2

Maxillofacial images must be examined to find pathologies not identified during clinical examination. Unicystic ameloblastoma (UA) extending to the mandibular body and ramus was neglected on initial panoramic radiographic examination. After orthodontic therapy, a huge lesion was observed clinically and through imaging exams. After the conservative surgery, no recurrence was observed during five years of follow-up. This case emphasized the need for careful evaluation of patient images focusing on the oral diagnosis before any dental treatment planning, including orthodontic therapy.

Lateral pterygoid muscle volume and migraine in patients with temporomandibular disorders

Sérgio Lúcio Pereira de Castro Lopes,André Luiz Ferreira Costa,Thiago de Oliveira Gamba,Isadora Luana Flores,Adriana Dibo Cruz,Li Li Min 대한영상치의학회 2015 Imaging Science in Dentistry Vol.45 No.1

Purpose: Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. Materials and Methods: Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fisher’s exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. Results: Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. Conclusion: In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable.

Mechanical Properties of Alumina Nanofilled Polymeric Composites Cured with DDSA and MNA

Ana M. Amaro,Deesy G. Pinto,Luís Bernardo,Sérgio Lopes,João Rodrigues,Cristina S. Louro 한국섬유공학회 2018 Fibers and polymers Vol.19 No.2

Reinforced concrete is widely used in structures. New materials to replace both the steel and the concrete have been studied in many research centres. One of the possibilities for the reinforcement is the partial or total replacement of the steel bars by new composite materials. Nano composites are very promising, and an investigation line was developed to this end by an interdisciplinary team. On this work, the mechanical properties of epoxy resin nanocomposites (EPNCs) filled with α-Al2O3 nanoparticles (NPs) with irregular shape and approximately 100 nm maximum diameter size was investigated. The variable study was the alumina NPs contents: 1, 3 and 5 wt.%. The NPs were previously pretreated with a silane agent (APTES). Two hardeners, 3-dodec-2-enyloxolane-2,5-dione (DDSA) and 8-methyl-3a,4,7,7a-tetrahydro-4,7-methano-2- benzofuran-1,3-dione (MNA), frequently used in epoxy resin embedding tissues, were used simultaneously for this study. Unlike other hardeners, DDSA does not need curing treatment, constituting a novel application and a saving time-energy during the manufacturing process. Considering the mechanical behaviour, it was observed that the EPNCs filled with 5 wt.% of alumina NPs showed the maximum improvement in flexural modulus, around 14 % when compared to the pristine EP sample. No relevant effect was observed on the flexural strength by adding alumina NPs. Additionally, the maximum increase observed for hardness, and Young’s modulus were about 13 % and 28 %, respectively (the maximum increase was observed at 3 wt.%).

Design and development of a digital platform for seasonal jobs: Improving the hiring process

Nuno Martins,Sérgio Dominique-Ferreira,Cátia Lopes 한국마케팅과학회 2022 마케팅과학연구 Vol.32 No.3

The seasonality of employment in tourism consists of challenges of hiring. The primary goal of this study was to develop a digital recruitment platform for the tourism industry. A two-step multidimensional approach was applied to the challenge. The first step was based on benchmarking and interviews with key stakeholders. The second step was based on visual identity factors, prototyping, and usability tests. Authors found that it was possible to develop a simple and intuitive digital platform that positively adjusted the dynamic hiring process for seasonal jobs. Improvements to the platform should include new metrics, such as evaluation of candidates who used this platform previously, based on different elements, such as emotional intelligence. In this way, profile matching could be optimized, and the platform tool would become more robust and useful. This study’s medium- and high-fidelity models of a digital platform to be utilized in human resources tasks are the new additions to toolkits that may streamline HR functions.

Study on Mechanical Properties and Fracture in Epoxy Composites Reinforced by Hybrid Twill Fabrics

Jorge Fernando de Sousa Oliveira,Mirtânia Antunes Leão,Ana Claudia Melo Caldas Batista,Sérgio Renan Lopes Tinô,Eve Maria Freire de Aquino 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

The aim of this study is to determine the influence of hybrid twill fabrics on the conception of polymer composites in terms of their mechanical properties and fracture mechanisms. Parameters associated with the type and/or process of hybridization, such as the presence or not of anisotropy, are influential factors in the final performance of these materials. For this, two composite laminates were manufactured, each containing four layers of reinforced hybrid twill fabrics made from Kevlar-49/AS4 carbon and Kevlar-49/E-glass fibers, with a high-performance epoxy vinyl ester as matrix. Mechanical properties were performed for uniaxial tensile, three-point bending and uniaxial compression tests. The type of hybrid twill fabric directly affected the mechanical properties and damage mechanism of the laminates studied for all loads applied. Highlight that specimens tested to carbon direction exhibited better mechanical behavior.

Texture analysis in cone-beam computed tomographic images of medication-related osteonecrosis of the jaw

Queiroz Polyane Mazucatto,Fardim Karolina Castilho,Costa André Luiz Ferreira,Matheus Ricardo Alves,Lopes Sérgio Lúcio Pereira Castro 대한영상치의학회 2023 Imaging Science in Dentistry Vol.53 No.2

Purpose: The aim of this study was to evaluate changes in the trabecular bone through texture analysis and compare the texture analysis characteristics of different areas in patients with medication-related osteonecrosis of the jaw (MRONJ). Materials and Methods: Cone-beam computed tomographic images of 16 patients diagnosed with MRONJ were used. In sagittal images, 3 regions were chosen: active osteonecrosis (AO); intermediate tissue (IT), which presented a zone of apparently healthy tissue adjacent to the AO area; and healthy bone tissue (HT) (control area). Texture analysis was performed evaluating 7 parameters: secondary angular momentum, contrast, correlation, sum of squares, inverse moment of difference, sum of entropies, and entropy. Data were analyzed using the Kruskal-Wallis test with a significance level of 5%. Results: Comparing the areas of AO, IT, and HT, significant differences (P<0.05) were observed. The IT and AO area images showed higher values for parameters such as contrast, entropy, and secondary angular momentum than the HT area, indicating greater disorder in these tissues. Conclusion: Through texture analysis, changes in the bone pattern could be observed in areas of osteonecrosis. The texture analysis demonstrated that areas visually identified and classified as IT still had necrotic tissue, thereby increasing the accuracy of delimiting the real extension of MRONJ.

Cone-beam computed tomography texture analysis can help differentiate odontogenic and non-odontogenic maxillary sinusitis

Costa Andre Luiz Ferreira,Fardim Karolina Aparecida Castilho,Ribeiro Isabela Teixeira,Jardini Maria Aparecida Neves,Braz-Silva Paulo Henrique,Orhan Kaan,de Castro Lopes Sérgio Lúcio Pereira 대한영상치의학회 2023 Imaging Science in Dentistry Vol.53 No.1

Purpose: This study aimed to assess texture analysis (TA) of cone-beam computed tomography (CBCT) images as a quantitative tool for the differential diagnosis of odontogenic and non-odontogenic maxillary sinusitis (OS and NOS, respectively). Materials and Methods: CBCT images of 40 patients diagnosed with OS (N = 20) and NOS (N = 20) were evaluated. The gray level co-occurrence (GLCM) matrix parameters, and gray level run length matrix texture (GLRLM) parameters were extracted using manually placed regions of interest on lesion images. Seven texture parameters were calculated using GLCM and 4 parameters using GLRLM. The Mann-Whitney test was used for comparisons between the groups, and the Levene test was performed to confirm the homogeneity of variance (α = 5%). Results: The results showed statistically significant differences (P<0.05) between the OS and NOS patients regarding 3 TA parameters. NOS patients presented higher values for contrast, while OS patients presented higher values for correlation and inverse difference moment. Greater textural homogeneity was observed in the OS patients than in the NOS patients, with statistically significant differences in standard deviations between the groups for correlation, sum of squares, sum of entropy, and entropy. Conclusion: TA enabled quantitative differentiation between OS and NOS on CBCT images by using the parameters of contrast, correlation, and inverse difference moment.