Lack of direct association between oral mucosal lesions and SARS-CoV- 2 in a cohort of patients hospitalised with COVID-19.

Background: COVID-19 is a disease affecting various human organs and systems, in which the virus seeks to interact with angiotensin-converting enzyme 2 receptors. These receptors are present in the oral cavity, but the direct relationship between such an interaction and possible oral manifestations of COVID-19 is still unclear. Aim: The present study evaluated oral manifestations in a cohort of COVID-19 patients during the period of hospitalisation. Methods: In total, 154 patients presenting moderate-to-severe forms of COVID-19 had their oral mucosa examined twice a week until the final outcome, either discharge or death. The oral alterations observed in the patients were grouped into Group 1 (pre-existing conditions and opportunistic oral lesions) and Group 2 (oral mucosal changes related to hospitalization). Results: Oral lesions found in the patients of Group 1 are not suggestive of SARS-CoV-2 infection as they are mainly caused by opportunistic infections. On the other hand, oral alterations found in the patients of Group 2 were statistically (P < 0.001) related to intubation and longer period of hospitalisation. Conclusion: It is unlikely that ulcerative lesions in the oral cavity are a direct manifestation of SARS-CoV-2 or a marker of COVID-19 progression.

Comparison of Immunohistochemistry and DNA Sequencing for BRAF V600E Mutation Detection in Mandibular Ameloblastomas.

This study aimed to investigate the presence of BRAF V600E mutation in mandibular ameloblastoma by comparing the results of molecular detection and immunohistochemical analysis. A 128 cases of mandibular ameloblastoma and 30 cases of dentigerous cyst (control group) were selected for analysis. Detection of BRAF V600E mutation was performed with immunohistochemistry (IHC) and polymerase chain reaction techniques. Clinico-pathologic data were collected in order to investigate possible associations with the mutation. Of the 128 cases submitted to IHC, 81.2% (108 cases) showed positivity for anti-BRAF V600E antibody, whereas 24 were negative (18.8%). Molecular analysis of the BRAF V600E mutation by polymerase chain reaction was possible in 116 cases due to DNA quality. Of these cases, 96 were positive (82.8%) and 20 negative (17.2%). All cases of dentigerous cyst were negative for BRAF V600E mutation in both techniques. Considering the sequencing as a gold standard method, the receiver operating characteristics curve analysis showed sensitivity of 0.99 and specificity of 1 (area under the curve=0.995, standard error=0.006; P<0.001; 95% confidence interval=0.983 to 1). We also tested the agreement between the techniques by using the Cohen's κ coefficient, with κ being 0.97 (P<0.001). IHC is a reliable test for identifying the BRAF V600E mutation in ameloblastomas, presenting advantages such as being more frequently used in surgical pathology laboratories and requiring fewer critical steps for paraffin-embedded tissue compared with molecular biology techniques.

Oral shedding of CMV and HSV-1 in hematopoietic stem cell transplantation patients.

OBJECTIVES: To evaluate the oral shedding of herpesviruses in patients undergoing hematopoietic stem cell transplantation (HSCT) and correlate it with oral mucositis (OM). METHODS: Saliva samples were collected before the HSCT and on day D + 8. Multiplex Polymerse Chain Reaction (PCR) was performed to detect herpes simplex virus (HSV)-1 and HSV-2, Epstein-Barr virus (EBV), Cytomegalovirus (CMV), Variella-zoster virus (VZV), and human herpesvirus (HHV)-6, HHV-7, and HHV-8. OM was assessed according to WHO criteria. RESULTS: Thirty one patients were enrolled, in which 20 of 31 (64.5%) were males; median age was 50 (21-70) years; 16 of 31 (51.6%) underwent allo-HSCT; and 15 of 31 (48.4%) underwent auto-HSCT. On D + 8, OM grades III and IV were observed in 8 of 31 (25.8%) patients. In the first salivary collection, EBV was found in 24 of 31 (77.4%), followed by HHV-6 (7/31, 22.6%) and HHV-7 (8/31 25.8%). In the second collection, EBV was found in 24 of 27(89%), followed by HSV-1 (8/27, 30%) and CMV, HHV-6, and HHV-7 (5/27, 18.5%, each one). On D + 8, OM grades II and IV were associated with the presence of HSV-1. HSV-1 was also associated with worsening degrees of OM on D + 15. CONCLUSION: The presence of HSV-1 and CMV in oral samples was more frequent on day D + 8 after HSCT. HSV-1 detection was associated with severity and worsening of OM. HSV-1 and CMV seem to be associated with oral dysbiosis due to HSCT.

In vivo assessment of the corrosion of nickel-titanium orthodontic archwires by using scanning electron microscopy and atomic force microscopy.

This study was undertaken to assess in vivo the corrosion in two commercial nickel-titanium (NiTi) orthodontic archwires removed from the oral cavity of patients using fluoride mouthwashes. Five volunteers took part in this study on the corrosion behavior of two brands of NiTi archwires (3M and AO (brand of archwire)) during use of two mouthwashes with neutral sodium fluoride 1.1%, one with acidulated fluoride 1.1%, and one with placebo and a control group. Each patient used one mouthwash in three different periods of time for 1 min a day for 30 days. The archwires were assessed with scanning electron microscopy and atomic force microscopy for qualitative and quantitative analysis. The values obtained with atomic force microscopy (AFM) were submitted to normality test, two-way analysis of variance, and Tukey's test at a significance level of 5%. The AFM images showed a gradual qualitative increase in the roughness of both types of wire between the treatments: control < placebo < neutral fluoride < acidulated fluoride. The arithmetic average of the roughness and root mean square of the roughness were similar. As for 3M archwires, only the acidulated fluoride group differed statistically from the others. As for AO archwires, the control and placebo groups did not differ from each other, but differed from the other fluoride treatments. The group using neutral fluoride also differed significantly from the acidulated fluoride group. 3M archwires were not affected by daily oral challenges. AO archwires were not affected by daily oral challenges either; their association with fluoride, either neutral or acidulated, increased their roughness.

Evaluation of lower anterior dental changes in patients treated with self-ligating brackets.

The aim of this study was to evaluate and compare changes in linear distance and inclination of lower incisors and canines and intercanine distance after a 30 months orthodontic treatment with self-ligating appliances. Seven patients were treated orthodontically with a Roth prescription passive self-ligating bracket. To perform the measurements and comparisons, CBCT scans were taken before the start of the orthodontic treatment (T1) and after a period of 30 months treatment (T2). The following measurements were performed: (1) the lower incisors and canines inclination in relation to the mandibular plane, (2) intercanine linear distance in millimeters and (3) linear distance in millimeters of the incisal and apical part of lower anterior teeth to a plane (POGM) passing through pogonion point and perpendicular to the mandibular plane. No significant difference were observed between T1 and T2 for canine inclination (p = 0.835), incisors inclination (p = 0.149), canine incisal distance to POGM (p = 0.423) and incisors incisal distance to POGM (p = 0.966), however canine apical distance (p = 0.049) and incisors apical distance (p = 0.002) to POGM was lower at T1 than at T2. The intercanine distance was significantly lower (p = 0.022) at T1 when compared to T2. The use of passive self-ligating brackets in orthodontic treatment to solve 4 mm tooth crowding were able to produce dental arch expansion by bodily tooth movement.

Inclination of the condylar long axis is not related to temporomandibular disc displacement.

AIM: The aim of the present study was to correlate the angle formed by inclination of the condylar long axis and median sagittal plane to the presence of internal disc derangement, as well as changes in eccentric mandibular positions. METHODS: The sample consisted of magnetic resonance images of 35 temporomandibular joint (TMJ) acquired with a 1.5T magnetic resonance imaging system with surface coils of 8.5 cm in diameter. Parasagittal images were used according to the following parameters: TMJ disc position with mouth closed, TMJ disc position with mouth open, TMJ disc function, and degrees of rotation and translation of the condyle. Next, we determined the angles between the condyle long axis and median sagittal plane by using axial images. RESULTS: The results showed correlations between TMJ disc position and disc function (P = 0.009), as well as between disc position and degree of condylar rotation (P = 0.008). The main purpose of the present study was to assess the angle of the condylar long axis, with no statistical correlation being found between this variable and disc position (P = 0.787), disc function (P = 0.091), condylar translation (P = 0.808), and condylar rotation (P = 0.115). CONCLUSION: There was no relationship between inclination of the condyle long axis and parameters of internal derangements.

Cervical vertebrae maturation index estimates on cone beam CT: 3D reconstructions vs sagittal sections.

OBJECTIVES: The aim of this study was to evaluate the performance of CBCT three-dimensional (3D) reconstructions and sagittal sections for estimates of cervical vertebrae maturation index (CVMI). METHODS: The sample consisted of 72 CBCT examinations from patients aged 8-16 years (45 females and 27 males) selected from the archives of two private clinics. Two calibrated observers (kappa scores: ≥0.901) interpreted the CBCT settings twice. Intra- and interobserver agreement for both imaging exhibition modes was analyzed by kappa statistics, which was also used to analyze the agreement between 3D reconstructions and sagittal sections. Correlations between cervical vertebrae maturation estimates and chronological age, as well as between the assessments by 3D reconstructions and sagittal sections, were analyzed using gamma Goodman-Kruskal coefficients (α = 0.05). RESULTS: The kappa scores evidenced almost perfect agreement between the first and second assessments of the cervical vertebrae by 3D reconstructions (0.933-0.983) and sagittal sections (0.983-1.000). Similarly, the agreement between 3D reconstructions and sagittal sections was almost perfect (kappa index: 0.983). In most divergent cases, the difference between 3D reconstructions and sagittal sections was one stage of CVMI. Strongly positive correlations (>0.8, p < 0.001) were found not only between chronological age and CVMI but also between the estimates by 3D reconstructions and sagittal sections (p < 0.001). CONCLUSIONS: Although CBCT imaging must not be used exclusively for this purpose, it may be suitable for skeletal maturity assessments.

Sequential imaging of an impacted mandibular second premolar migrated from angle to condyle.

Extreme distal migration of impacted teeth to the subcondylar area and condyle is very rare. Using an interesting sequence of radiographs showing the path of the tooth in the mandible, we describe the intrabony migration of a mandibular second premolar from angle to condyle in a young woman. Cone-beam computed tomography was used to establish the precise location of the tooth.

Voxel-based morphometry and intellectual assessment in patients with congenital bilateral perisylvian syndrome.

Congenital bilateral perisylvian syndrome (CBPS) presents with heterogeneous clinical manifestations such as pseudobulbar palsy, language disorder, variable cognitive deficits, epilepsy, and perisylvian abnormalities (most frequently polymicrogyria) on imaging studies. We investigated the relationship between seizures and extent of gray matter (GM) and white matter (WM) abnormalities using voxel-based morphometry (VBM) of brain magnetic resonance imaging (MRI) as well the association between seizures, structural abnormalities and cognitive ability. In this cross-sectional study, we evaluated 51 healthy volunteers and 18 patients with CBPS with epilepsy (seizure group, n = 7) and without (non-seizure group, n = 11). We used VBM (SPM8/DARTEL) to investigate areas with excess and atrophy of both gray and white matter, comparing groups of patients with controls. Intellectual ability of patients was assessed by the WISC-III or WAIS-III. Both groups with CBPS and the control group were homogeneous with respect to gender (p = 0.07) and age (p = 0.065). Besides perisylvian polymicrogyria, the seizure group exhibited areas with GM and WM reduction including temporal, frontal, parietal and occipital lobes. In contrast, we identified fewer areas with GM and WM reduction in the non-seizure group. The seizure group presented worse intellectual performance (performance IQ and global IQ) than the non-seizure group. The seizure group presented with a more widespread pattern of cortical and sub-cortical abnormalities, as well as worse cognition. Our results suggest that patients with CBPS and epilepsy appear to have widespread neuronal damage that goes beyond the areas with MRI-visible perisylvian polymicrogyria.

The association between periodontal disease and seizure severity in refractory epilepsy patients.

PURPOSE: Periodontal diseases are common in most populations and affect people at all socioeconomic levels. Evidence suggests that patients with epilepsy actually have higher risks of dental disease and increased oral health needs, but the frequency and consequences of poor controlled seizures on dental and periodontal health have not been reported before. We aimed to assess the impact of seizure frequency on periodontal status and oral hygiene in a sample of epilepsy patients. METHODS: One hundred and nine consecutive patients treated for epilepsy at the outpatient clinic of our University Hospital were invited to take part in an oral examination to determine their periodontal disease status, together with a control group. In addition, seizure frequency and use of medication were documented. RESULTS: In logistic regression model, patients were significantly more susceptible to bad oral hygiene, gingivitis and periodontitis that controls (p<0.001); seizure frequency was significantly related to bad oral hygiene (p=0.010), gingivitis (p<0.001) and periodontitis (p<0.001). Tooth brushing habits and presence of caries were associated with oral health in patients group. CONCLUSION: Our study found a significant positive correlation between periodontal disease and seizure severity. Epilepsy patients need to focus more on their oral health and quality of oral hygiene.

Brain Perfusion Impairment in Neurologically Asymptomatic Adult Patients with Sickle-Cell Disease Shown by Voxel-Based Analysis of SPECT Images.

Cerebrovascular lesions are frequently observed in patients with sickle-cell disease (SCD) and these structural lesions are preceded by insidious perfusion deficits. Our aim was to investigate the presence of brain perfusion deficits in neurologically asymptomatic SCD patients, especially affecting microvessels. For this study, 42 SCD patients [33 sickle-cell anemia (HbSS), 6 sickle hemoglobin C disease (HbSC), and 3 sickle ß-thalassemia disease (HbSß)] with mean hematocrit of 25.1 (±4.85; 15.6-38.5) underwent brain perfusion single photon emission computerized tomography (SPECT) using the tracer (99m)Tc-ECD. Images from SCD patients were compared to images of a healthy control group (29 females and 20 males, mean age 31 ± 8; range 25-49 years). Images underwent voxel-wise comparison of regional tracer uptake using paired t-test to estimate the probability of each voxel to have an increased or decreased tracer uptake. When compared to controls, SCD patients exhibited significantly reduced tracer uptake in basal ganglia and thalami, the anterior frontal region and the watershed region of the temporo-parietal-occipital transition (p < 0.05). Our study showed that neurologically asymptomatic adult SCD patients exhibit a pattern of reduced (99m)Tc-ECD tracer uptake demonstrated by SPECT. Early diagnosis of this cerebral vasculopathy has prognostic implications and can be determinant in considering therapeutic alternatives to avoid increasing brain lesion load and progressive disability.

Artifacts in brain magnetic resonance imaging due to metallic dental objects

Objective: Artifacts caused by metallic objects, such as dental crowns, dental implants and metallic orthodontic appliances, are a common problem in head and neck MRI. The aim of this retrospective study was to identify the main metal dental objects that produce artifacts on brain MRIs. Study design: Imaged metallic artifacts and their sources were identified. Artifact image plane was rated on a score of 0 or 1 (0 - distinguishable for diagnosis and 1 - not distinguishable for diagnosis). Results: Seventy-eight percent of the artifacts appearing in images were caused by orthodontic appliances, followed by dental titanium implants (18%) and metallic crowns (4%). Orthodontic appliances obtained the highest scores in all planes. Conclusions: We concluded that is difficult to avoid the effect of metallic artifacts in the maxillofacial regions on brain scan. Removing metallic parts of the orthodontic appliance should ensure diagnostically useful quality scans (AU)

Artifacts in brain magnetic resonance imaging due to metallic dental objects.

OBJECTIVE: Artifacts caused by metallic objects, such as dental crowns, dental implants and metallic orthodontic appliances, are a common problem in head and neck MRI. The aim of this retrospective study was to identify the main metal dental objects that produce artifacts on brain MRIs. STUDY DESIGN: Imaged metallic artifacts and their sources were identified. Artifact image plane was rated on a score of 0 or 1 (0--distinguishable for diagnosis and 1--not distinguishable for diagnosis). RESULTS: Seventy-eight percent of the artifacts appearing in images were caused by orthodontic appliances, followed by dental titanium implants (18%) and metallic crowns (4%). Orthodontic appliances obtained the highest scores in all planes. CONCLUSIONS: We concluded that is difficult to avoid the effect of metallic artifacts in the maxillofacial regions on brain scan. Removing metallic parts of the orthodontic appliance should ensure diagnostically useful quality scans.

Temporomandibular joint internal derangement: association with headache, joint effusion, bruxism, and joint pain.

AIM: The aim of the present study was to assess the correlation of temporomandibular joint internal derangement (TMJ ID) in patients with the presence of headache, bruxism, and joint pain using magnetic resonance imaging (MRI). METHODS AND MATERIALS: This study evaluated 42 joints in 42 patients; 21 patients diagnosed with unilateral TMJ ID and a history of headaches and 21 patients diagnosed with unilateral TMD ID without a history of headaches. Signs of headache, bruxism, and joint pain were diagnosed clinically and were also obtained from the patient's history. Sixteen joints in 16 patients without signs or symptoms of TMD or headache were included as a control group. All patients underwent bilateral MRI of the TMJ to evaluate the disc position and the presence of joint effusion. Data were analyzed using Chi-square and Fischer's exact tests. RESULTS: Bruxing behavior was most frequently reported by patients with headaches (p<0.0125). Eighty-five percent of subjects with headaches also reported joint pain. A significant association was found between headache and TMJ effusion (p<0.0125). Patients with more severe disc displacement also had a higher frequency of effusion (p=0.001). CONCLUSION: The results suggest joint effusion may have a role in the pathogenesis of headache in TMJ ID. CLINICAL SIGNIFICANCE: Temporomandibular joint effusion on MRI may serve as a biological marker of headache associated with TMD and could be helpful for diagnostic classification and treatment follow up.

Comparison of conventional MRI and 3D reconstruction model for evaluation of temporomandibular joint.

The aim of this work was to define the diagnostic value of a method for 3D reconstruction of MRI images for the assessment of temporomandibular joint. Sixty subjects, 42 diagnosed with unilateral temporomandibular disorders (TMD) with disc displacement and 18 without signs or symptoms of TMD (control group) were included. All subjects had both temporomandibular joints scanned by MRI. Three-dimensional imaging reconstructions of temporomandibular joint were generated by segmentation software, allowing visualization of the components of temporomandibular joint (articular disc, condyle and temporal bone) on arbitrary planes. Disc displacement was observed in 83% of 3D reconstruction and 81% of conventional MRI. The agreement between 3D diagnosis and MRI findings was significant and high. The present analysis suggested that 3D reconstruction is a useful and accurate method for the assessment of the temporomandibular joint in TMD ID.

Imaging findings of Ewing's sarcoma in the mandible.

First described by James Ewing in 1921, Ewing's sarcoma (ES) or Ewing's tumor is one of the most aggressive bone tumors known. ES is an uncommon intra-osseous malignant tumor of questionable pathogenesis that occurs in children and young adults. Reports indicate that only 2 to 7% of cases involve the maxillofacial region, usually the mandible ramus, and few reported cases have involved the maxilla. In the present report of a case of ES of the mandible, we describe the results of imaging and evaluation after therapeutic treatment. This report provides a rare opportunity to observe radiologic features of ES in the mandible.