Isadora Luana Flores

Influence of cone-beam computed tomography image artifacts on the determination of dental arch measurements

OBJECTIVE To compare dental plaster model (DPM) and cone-beam computed tomography (CBCT) in the measurement of the dental arches, and investigate whether CBCT image artifacts compromise the reliability of such measurements. MATERIALS AND METHODS Twenty patients were divided into two groups based on the presence or absence of metallic restorations in the posterior teeth. Both dental arches of the patients were scanned with the CBCT unit i-CAT, and DPMs were obtained. Two examiners obtained eight arch measurements on the CBCT images and DPMs and repeated this procedure 15 days later. The arch measurements of each patient group were compared separately by the Wilcoxon rank sum (Mann-Whitney U) test, with a significance level of 5% (α  =  .05). Intraclass correlation measured the level of intraobserver agreement. RESULTS Patients with healthy teeth showed no significant difference between all DPM and CBCT arch measurements (P > .05). Patients with metallic restoration showed significant difference between DPM and CBCT for the majority of the arch measurements (P > .05). The two examiners showed excellent intraobserver agreement for both measuring methods with intraclass correlation coefficient higher than 0.95. CONCLUSION CBCT provided the same accuracy as DPM in the measurement of the dental arches, and was negatively influenced by the presence of image artifacts.

EEF1D modulates proliferation and epithelial–mesenchymal transition in oral squamous cell carcinoma

EEF1D (eukaryotic translation elongation factor 1δ) is a subunit of the elongation factor 1 complex of proteins that mediates the elongation process during protein synthesis via enzymatic delivery of aminoacyl-tRNAs to the ribosome. Although the functions of EEF1D in the translation process are recognized, EEF1D expression was found to be unbalanced in tumours. In the present study, we demonstrate the overexpression of EEF1D in OSCC (oral squamous cell carcinoma), and revealed that EEF1D and protein interaction partners promote the activation of cyclin D1 and vimentin proteins. EEF1D knockdown in OSCC reduced cell proliferation and induced EMT (epithelial-mesenchymal transition) phenotypes, including cell invasion. Taken together, these results define EEF1D as a critical inducer of OSCC proliferation and EMT.

Lateral pterygoid muscle volume and migraine in patients with temporomandibular disorders

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 Fishers 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.

ADAM17 mediates OSCC development in an orthotopic murine model

BackgroundADAM17 is one of the main sheddases of the cells and it is responsible for the cleavage and the release of ectodomains of important signaling molecules, such as EGFR ligands. Despite the known crosstalk between ADAM17 and EGFR, which has been considered a promising targeted therapy in oral squamous cell carcinoma (OSCC), the role of ADAM17 in OSCC development is not clear.MethodIn this study the effect of overexpressing ADAM17 in cell migration, viability, adhesion and proliferation was comprehensively appraised in vitro. In addition, the tumor size, tumor proliferative activity, tumor collagenase activity and MS-based proteomics of tumor tissues have been evaluated by injecting tumorigenic squamous carcinoma cells (SCC-9) overexpressing ADAM17 in immunodeficient mice.ResultsThe proteomic analysis has effectively identified a total of 2,194 proteins in control and tumor tissues. Among these, 110 proteins have been down-regulated and 90 have been up-regulated in tumor tissues. Biological network analysis has uncovered that overexpression of ADAM17 regulates Erk pathway in OSCC and further indicates proteins regulated by the overexpression of ADAM17 in the respective pathway. These results are also supported by the evidences of higher viability, migration, adhesion and proliferation in SCC-9 or A431 cells in vitro along with the increase of tumor size and proliferative activity and higher tissue collagenase activity as an outcome of ADAM17 overexpression.ConclusionThese findings contribute to understand the role of ADAM17 in oral cancer development and as a potential therapeutic target in oral cancer. In addition, our study also provides the basis for the development of novel and refined OSCC-targeting approaches.

Integrated Proteomics Identified Up-Regulated Focal Adhesion-Mediated Proteins in Human Squamous Cell Carcinoma in an Orthotopic Murine Model

Understanding the molecular mechanisms of oral carcinogenesis will yield important advances in diagnostics, prognostics, effective treatment, and outcome of oral cancer. Hence, in this study we have investigated the proteomic and peptidomic profiles by combining an orthotopic murine model of oral squamous cell carcinoma (OSCC), mass spectrometry-based proteomics and biological network analysis. Our results indicated the up-regulation of proteins involved in actin cytoskeleton organization and cell-cell junction assembly events and their expression was validated in human OSCC tissues. In addition, the functional relevance of talin-1 in OSCC adhesion, migration and invasion was demonstrated. Taken together, this study identified specific processes deregulated in oral cancer and provided novel refined OSCC-targeting molecules.

Oral presentation of 10 patients with Cowden syndrome

Cowden syndrome (CS) is an autosomal dominant genodermatosis that frequently affects several tissues with hamartomatous growth. The oral cavity is quite commonly involved with papillomatous lesions, which can be crucial to early diagnosis of this disease. In this series, 10 patients with a great diversity of manifestations associated with CS are presented, in whom oral papillomatosis was a constant and relevant finding to establish the diagnosis of CS. The role of the dentist in recognizing the oral lesions, the other diagnostic criteria, the risk for the development of malignancies, and the importance of lifetime follow-up are discussed.

A Wormian Bone, Mimicking an Entry Gunshot Wound of the Skull, in an Anthropological Specimen.

Wormian bones (WB) are irregular small cranial ossicles found along suture lines and fontanels. In Brazil, gunshot wounds to the skull are quite common in young individuals. Nevertheless, as far as we know, this is the first report of a WB giving an erroneous aspect of gunshot entrance due to its displacement position. The present manuscript describes the case of a Brazilian young man who died due to ballistic trauma, where a gaping bony defect on the right side of the skull was thought to be the exit wound of an injury related to the destruction found on the left side, highly suggestive of firearm injury. Thus, this case study has brought to light similarities between a traumatic lesion and an orifice of a WB, with emphasis on differential diagnosis during routine anthropological examinations.

Synchronous antiresorptive osteonecrosis of the jaws and breast cancer metastasis

Antiresorptive osteonecrosis of the jaws (ARONJ) is a significant and poorly understood oral complication that may affect patients receiving antiresorptive agents, such as intravenous bisphosphonate therapy. There are scarce reports of the coexistence of ARONJ and metastasis at the same jaw site in the English-language literature. In the present case, a 60-year-old white woman was referred for the evaluation of a nonhealing extraction socket. The patient was undergoing treatment with intravenous zoledronic acid to metastatic breast cancer in bone, and her medical history and clinical characteristics led to the diagnosis of ARONJ. Nevertheless, histologic analysis showed a fragment of necrotic bone and bacterial colonies associated with malignant epithelial cells that were confirmed to be metastatic breast adenocarcinoma. This case showed that jaw metastasis can occur at the same time and site of ARONJ, making diagnosis and management challenging.

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

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.

Low expression of angiotensinogen and dipeptidyl peptidase 1 in saliva of patients with proliferative verrucous leukoplakia

AIM To elucidate the profile of the salivary proteome. METHODS Unstimulated whole mouth saliva was collected from 30 volunteers [15 proliferative verrucous leukoplakia (PVL) patients and 15 controls] and proteins were submitted for mass spectrometry-based proteomics using the discovery approach, followed by analyses of variance and logistic regression tests. RESULTS A total of two hundred and eighty-three proteins were confidently identified in saliva. By combining two low abundance proteins from the PVL group, angiotensinogen (AGT) and dipeptidyl peptidase 1 (DPP1), a model for group differentiation was built with a concordance index of 94.2%, identifying both proteins as potential etiologic biomarkers for PVL. CONCLUSION This study suggests that both AGT and DPP1 may be involved in developmental mechanisms of PVL.