80 resultados para Computed Tomography


Relevância:

60.00% 60.00%

Publicador:

Resumo:

There has been a significant increase in the number of facial fractures stemming from sport activities in recent years, with the nasal bone one of the most affected structures. Researchers recommend the use of a nose protector, but there is no standardization regarding the material employed. Clinical experience has demonstrated that a combination of a flexible and rigid layer of ethylene vinyl acetate (EVA) offers both comfort and safety to practitioners of sports. The aim of the present study was the investigation into the stresses generated by the impact of a rigid body on the nasal bone on models with and without an EVA protector. For such, finite element analysis was employed. A craniofacial model was constructed from images obtained through computed tomography. The nose protector was modeled with two layers of EVA (1 mm of rigid EVA over 2 mm of flexible EVA), following the geometry of the soft tissue. Finite element analysis was performed using the LS Dyna program. The bone and rigid EVA were represented as elastic linear material, whereas the soft tissues and flexible EVA were represented as hyperelastic material. The impact from a rigid sphere on the frontal region of the face was simulated with a constant velocity of 20 m s-1 for 9.1 mu s. The model without the protector served as the control. The distribution of maximal stress of the facial bones was recorded. The maximal stress on the nasal bone surpassed the breaking limit of 0.130.34 MPa on the model without a protector, while remaining below this limit on the model with the protector. Thus, the nose protector made from both flexible and rigid EVA proved effective at protecting the nasal bones under high-impact conditions.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Objectives/Hypothesis: Demonstrate the endoscopic anatomy of the palatovaginal (PV) canal and artery for identification and dissection of the vidian nerve during endoscopic transpterygoid approaches. Evaluate the length of the PV canal and its relation with the vidian nerve. Show that the traditionally known PV canal is a misnomer and should be renamed. Study Design: Experimental study: anatomical and radiological. Methods: Dissection of eight cadaveric heads was performed to demonstrate the endoscopic anatomy of the PV canal. Computed tomography scan analysis of 20 patients was used to evaluate the length of the PV canal, the angle formed between this canal and the vidian nerve, and the distance between the vidian canal and the PV canal. Study of 10 dry skull bases was performed to verify the structures involved in the formation of the PV canal. Results: Anatomic steps and foundations for dissection of the vidian nerve using the PV canal as a landmark were described. The mean length of the PV canal was 7.15 mm. The mean proximal distance between the vidian and the PV canal was 1.95 mm, and the mean distal distance was 4.14 mm. The mean angle between those canals was 48 degrees. The osteology study showed the vaginal process of the sphenoid bone did not contribute to the formation of the PV canal. Conclusions: Our anatomic investigations, radiologic studies, and surgical experience demonstrate the important anatomic relationship of the PV canal with the vidian canal and the relevance of the PV canal as a surgical landmark in endoscopic endonasal transpterygoid approaches. Anatomically, PV canal is a misnomer and should be replaced with palatosphenoidal canal.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Introduction: Orbital infections may result in permanent morbidity because of the severity of infection. Furthermore, delayed diagnosis or treatment of orbital infections can lead to intracranial complications and even death. The majority of orbital infections develop from paranasal sinus infections, cutaneous infections, and periorbital trauma. Dacryocystitis and odontogenic infection are also accounted as potential etiologies but are scarcely reported in scientific literature. Methods: The patient revealed a history of having endodontic treatment on left maxillary second molar performed 2 weeks previously. Moreover, she exhibited signs of facial pain accompanied by sinusitis symptoms, fever, and nasal obstruction the week after this endodontic procedure. The patient presented proptosis, impairment of ocular motility to the right side, facial tenderness, palpebral erythema, and referred decreased visual acuity. Intraoral exam revealed root fragments of left maxillary first molar and an extensive carious lesion on left maxillary second molar. Computed tomography enabled the observation of frontal sinus, left-sided maxillary, opacity of sphenoidal and ethmoidal sinuses, and apical lesion of left maxillary first and second molars, all suggesting the presence of their apex in the maxillary sinus. In addition, images revealed ocular proptosis and presence of high-density areas suggestive of pus in the medial orbital wall region. Results: The patient was submitted to surgical drainage under general anesthesia approximately 8 hours after the clinical evaluation. Conclusions: Early detection of orbital infection, proper diagnostic tests, and treatment may provide successful outcomes of this rarely occurring disease. (J Endod 2012;38:1541-1543)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Objectives: A wide variety of manifestations is presented in patients with Gaucher's disease (GD), including bone, haematology and visceral disturbances. This study was conducted to ascertain the main maxillofacial abnormalities by means of clinical survey, panoramic and cone beam CT (CBCT); to compare the patient's group with an age-sex matched control group; and to correlate clinical and radiological data. Methods: Ten patients previously diagnosed with GD were submitted to clinical and radiological surveys (CBCT and panoramic radiographs). The examination consisted of anamnesis, extra- and intraoral examinations and analyses of each patient's records. Imaging data were collected from the point of view of 3 observers, and the results compared with a healthy group (20 individuals) by means of statistical analysis (Fisher's exact test). Results: Gaucher patients had significantly more manifestations than otherwise healthy carriers. The most prevalent findings were enlarged marrow spaces, generalized osteopenia and effacement of jaw structures (mandibular canal, lamina dura and mental foramen). Here we describe a case in which thickening of the maxillary sinus mucosa was observed on CBCT rather than opacification of the sinus as seen on panoramic radiographs. Pathological fractures, root resorption and delay on tooth eruption were not observed. Conclusions: A poor relationship could be observed between clinical and radiological data. Patients showed important bone manifestations, which require careful diagnostic and surgical planning whenever necessary. Although panoramic radiographs have shown significant differences, CBCT is more effective in pointing out differences between patients and a control group, thus showing it as an important tool for evaluation of Gaucher patients. Dentomaxillofacial Radiology (2012) 41, 541-547. doi: 10.1259/dmfr/143023353

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Introduction: Intestinal intussusception is a rare disease out of childhood. It is represented by an invagination of a bowel into the lumen of the adjacent segment. Case Report: This article reports a case of 14 year-old patient presenting intestinal obstruction caused by an intussusception at the level of the terminal ileum. A surgical resection of the invaginated segment was done and the histopathological study disclosed no evidence of malignancy. Discussion: In children, it is usually idiopathic, but among adolescents and adults it is often related to anatomic lesions, some of them neoplastic with high risk of malignancy. Preoperative diagnosis of intestinal intussusception is difficult due to its nonspecific and subacute symptoms. Computed tomography and ultrassonography can confirm the intussusception through characteristic images. Conclusion: Intestinal intussusception in adolescents is a rare and often misdiagnosed disease, deserving special attention from surgeons and general doctors.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

BACKGROUND AND PURPOSE: DON, a serious complication of GO, is frequently difficult to diagnose clinically in its early stages because of confounding signs and symptoms of congestive orbitopathy. We evaluated the ability of square area measurements of orbital apex crowding, calculated with MDCT, to detect DON. MATERIALS AND METHODS: Fifty-six patients with GO were studied prospectively with complete neuro-ophthalmologic examination and MDCT scanning. Square measurements were taken from coronal sections 12 mm, 18 mm, and 24 mm from the interzygomatic line. The ratio between the extraocular muscle area and the orbital bone area was used as a Cl. Intracranial fat prolapse through the superior orbital fissure was recorded as present or absent. Severity of optic nerve crowding was also subjectively graded on corona! images. Orbits were divided into 2 groups (with or without clinical evidence of DON) and compared. RESULTS: Ninety-five orbits (36 with and 59 without DON) were studied. The CIs at all 3 levels and the subjective crowding score were significantly greater in orbits with DON (P<.001). No significant difference was observed regarding intracranial fat prolapse (P=.105). The area under the ROC curves was 0.91, 0.93, and 0.87 for CIs at 12, 18, and 24 mm, respectively. The best performance was at 18 mm, where a cutoff value of 57.5% corresponded to 91.7% sensitivity, 89.8% specificity, and an odds ratio of 97.2 for detecting DON. A significant correlation (P<.001) between the CIs and VF defects was observed. CONCLUSIONS: Orbital Cls based on area measurements were found to predict DON more reliably than subjective grading of orbital crowding or intracranial fat prolapse.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Sinus floor augmentation has been established as a predictable technique to overcome maxillary bone loss. Antral cystic lesions may lead to intrasurgical complications and should be accurately diagnosed. However, antral pseudocysts have recently been described not to be contraindicated for sinus-grafting procedures. The current article sought to report clinical, cone beam computed tomographic, and histologic results of a maxillary sinus floor augmentation, performed with piezoelectric surgery, in the presence of a large antral pseudocyst. Success of graft maturation was confirmed with histologic analysis, which also indicated the absence of inflammatory infiltration in the tissue evaluated. On the basis of our findings, it is possible to perform a predictable treatment based on sinus floor augmentation in the presence of antral pseudocysts. Graft maturation can also be achieved 6 months after sinus-lifting surgeries.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Facial reconstruction is a method that seeks to recreate a person's facial appearance from his/her skull. This technique can be the last resource used in a forensic investigation, when identification techniques such as DNA analysis, dental records, fingerprints and radiographic comparison cannot be used to identify a body or skeletal remains. To perform facial reconstruction, the data of facial soft tissue thickness are necessary. Scientific literature has described differences in the thickness of facial soft tissue between ethnic groups. There are different databases of soft tissue thickness published in the scientific literature. There are no literature records of facial reconstruction works carried out with data of soft tissues obtained from samples of Brazilian subjects. There are also no reports of digital forensic facial reconstruction performed in Brazil. There are two databases of soft tissue thickness published for the Brazilian population: one obtained from measurements performed in fresh cadavers (fresh cadavers' pattern), and another from measurements using magnetic resonance imaging (Magnetic Resonance pattern). This study aims to perform three different characterized digital forensic facial reconstructions (with hair, eyelashes and eyebrows) of a Brazilian subject (based on an international pattern and two Brazilian patterns for soft facial tissue thickness), and evaluate the digital forensic facial reconstructions comparing them to photos of the individual and other nine subjects. The DICOM data of the Computed Tomography (CT) donated by a volunteer were converted into stereolitography (STL) files and used for the creation of the digital facial reconstructions. Once the three reconstructions were performed, they were compared to photographs of the subject who had the face reconstructed and nine other subjects. Thirty examiners participated in this recognition process. The target subject was recognized by 26.67% of the examiners in the reconstruction performed with the Brazilian Magnetic Resonance Pattern, 23.33% in the reconstruction performed with the Brazilian Fresh Cadavers Pattern and 20.00% in the reconstruction performed with the International Pattern, in which the target-subject was the most recognized subject in the first two patterns. The rate of correct recognitions of the target subject indicate that the digital forensic facial reconstruction, conducted with parameters used in this study, may be a useful tool. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Statement of problem. The retention of an Aramany Class IV removable partial dental prosthesis can be compromised by a lack of support. The biomechanics of this obturator prosthesis result in an unusual stress distribution on the residual maxillary bone. Purpose. This study evaluated the biomechanics of an Aramany Class IV obturator prosthesis with finite element analysis and a digital 3-dimensional (3-D) model developed from a computed tomography scan; bone stress was evaluated according to the load placed on the prosthesis. Material and methods. A 3-D model of an Aramany Class IV maxillary resection and prosthesis was constructed. This model was used to develop a finite element mesh. A 120 N load was applied to the occlusal and incisal platforms corresponding to the prosthetic teeth. Qualitative analysis was based on the scale of maximum principal stress; values obtained through quantitative analysis were expressed in MPa. Results. Under posterior load, tensile and compressive stresses were observed; the tensile stress was greater than the compressive stress, regardless of the bone region, and the greatest compressive stress was observed on the anterior palate near the midline. Under an anterior load, tensile stress was observed in all of the evaluated bone regions; the tensile stress was greater than the compressive stress, regardless of the bone region. Conclusions. The Aramany Class IV obturator prosthesis tended to rotate toward the surgical resection when subjected to posterior or anterior loads. The amount of tensile and compressive stress caused by the Aramany Class IV obturator prosthesis did not exceed the physiological limits of the maxillary bone tissue. (J Prosthet Dent 2012;107:336-342)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Objective: To evaluate the clinical outcomes of multivisceral transplantation (MVT) in the setting of diffuse thrombosis of the portomesenteric venous system. Background: Liver transplantation (LT) in the face of cirrhosis and diffuse portomesenteric thrombosis (PMT) is controversial and contraindicated in many transplant centers. LT using alternative techniques such as portocaval hemitransposition fails to eliminate complications of portal hypertension. MVT replaces the liver and the thrombosed portomesenteric system. Methods: A database of intestinal transplant patients was maintained with prospective analysis of outcomes. The diagnosis of diffuse PMT was established with dual-phase abdominal computed tomography or magnetic resonance imaging with venous reconstruction. Results: Twenty-five patients with grade IV PMT received 25 MVT. Eleven patients underwent simultaneous cadaveric kidney transplantation. Biopsy-proven acute cellular rejection was noted in 5 recipients, which was treated successfully. With a median follow-up of 2.8 years, patient and graft survival were 80%, 72%, and 72% at 1, 3, and 5 years, respectively. To date, all survivors have good graft function without any signs of residual/recurrent features of portal hypertension. Conclusions: MVT can be considered as an option for the treatment of patients with diffuse PMT. MVT is the only procedure that completely reverses portal hypertension and addresses the primary disease while achieving superior survival results in comparison to the alternative options.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The pathophysiology of neurodegenerative diseases (ND) such as Alzheimer's disease (AD) and Parkinson's disease (PD) has not yet been completely elucidated. However, in the past few years, there have been great knowledge advances about intra-and extracellular proteins that may display impaired function or expression in AD, PD and other ND, such as amyloid beta (AB), alpha-synuclein, tau protein and neuroinfiammatory markers. Recent developments in the imaging techniques of positron emission tomography (PET) and single photon emission computed tomography (SPECT) now allow the non-invasive tracking of such molecular targets of known relevance to ND in vivo. This article summarizes recent findings of PET and SPECT studies using these novel methods, and discusses their potential role in the field of drug development for ND as well as future clinical applications in regard to differential diagnosis of ND and monitoring of disease progression.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Context: Liposuction is suggested to result in long-term body fat regain that could lead to increased cardiometabolic risk. We hypothesized that physical activity could prevent this effect. Objective: Our objective was to investigate the effects of liposuction on body fat distribution and cardiometabolic risk factors in women who were either exercise trained or not after surgery. Design, Setting, and Participants: Thirty-six healthy normal-weight women participated in this 6-month randomized controlled trial at the University of Sao Paulo, Sao Paulo, Brazil. Interventions: Patients underwent a small-volume abdominal liposuction. Two months after surgery, the subjects were randomly allocated into two groups: trained (TR, n = 18, 4-month exercise program) and nontrained (NT, n = 18). Main Outcome Measures: Body fat distribution (assessed by computed tomography) was assessed before the intervention (PRE) and 2 months (POST2), and 6 months (POST6) after surgery. Secondary outcome measures included body composition, metabolic parameters and dietary intake, assessed at PRE, POST2, and POST6, and total energy expenditure, physical capacity, and sc adipocyte size and lipid metabolism-related gene expression, assessed at PRE and POST6. Results: Liposuction was effective in reducing sc abdominal fat (PRE vs. POST2, P = 0.0001). Despite the sustained sc abdominal fat decrement at POST6 (P = 0.0001), the NT group showed a significant 10% increase in visceral fat from PRE to POST6 (P = 0.04; effect size = -0.72) and decreased energy expenditure (P = 0.01; effect size = 0.95) when compared with TR. Dietary intake, adipocyte size, and gene expression were unchanged over time. Conclusion: Abdominal liposuction does not induce regrowth of fat, but it does trigger a compensatory increase of visceral fat, which is effectively counteracted by physical activity. (J Clin Endocrinol Metab 97: 2388-2395, 2012)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Carcinosarcoma is a rare malignant disease with aggressive behaviour rarely producing oral manifestations. This article reports a case of an intraoral carcinosarcoma affecting a 71-year-old black male; the diagnosis was made by histopathological and immunohistochemical analyses. Computed tomography scanning showed metastatic masses in the lungs. The patient was underwent a chemotherapy protocol regimen, but died as a consequence of the disease within 10 months of diagnosis. Distinctive characteristics of this presentation were the location of the lesion (floor of the mouth) and its clinical features resembling a benign lesion. A brief review of intraoral carcinosarcoma cases in the literature is also presented.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Context: Jansen's metaphyseal chondrodysplasia (JMC) is a rare autosomal dominant disorder caused by activating mutations in the PTH 1 receptor (PTH1R; PTH/PTHrP receptor), leading to chronic hypercalcemia and hypercalciuria. Hypophosphatemia is also a hallmark of JMC, and recently, increased fibroblast growth factor 23 (FGF23) levels have been reported in this syndrome. Hypercalcemia has been associated with increased cardiovascular risk; however, cardiovascular disease has not been extensively investigated in JMC patients. Objective: The aim of the study was to describe the long-term follow-up of a JMC patient with regard to the management of hypercalciuria, the evaluation of FGF23 levels under bisphosphonate treatment, and the investigation of cardiovascular repercussion of chronic hypercalcemia. Results: The diagnosis of JCM was confirmed by molecular analysis (p.H223R mutation in PTH1R). The patient was followed from 5 to 27 yr of age. Asymptomatic nephrolithiasis was diagnosed at 18 yr of age, prompting pharmacological management of hypercalciuria. Treatment with alendronate reduced hypercalciuria; however, normocalciuria was only obtained with the association of thiazide diuretic. Serum FGF23 levels, measured under alendronate treatment, were repeatedly within the normal range. Subclinical cardiovascular disease was investigated when the patient was 26 yr old, after 19 yr of sustained mild hypercalcemia; carotid and vertebral artery ultrasonography was normal, as well as coronary computed tomography angiography (calcium score = 0). Conclusion: The long-term follow-up of our JMC patient has provided insight on therapeutic strategies to control hypercalciuria, on the potential effects of alendronate on FGF23 levels, and on the lack of detectable cardiovascular disease at young adulthood after prolonged exposure to hypercalcemia. (J Clin Endocrinol Metab 97: 1098-1103, 2012)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

High serum phosphorus levels have been associated with mortality and cardiovascular events in patients with chronic kidney disease and in the general population. In addition, high phosphorus levels have been shown to induce vascular calcification and endothelial dysfunction in vitro. The aim of this study was to evaluate the relation of phosphorus and coronary calcification and atherosclerosis in the setting of normal renal function. This was a cross-sectional study involving 290 patients with suspected coronary artery disease and undergoing elective coronary angiography, with a creatinine clearance >60 ml/min/1.73 m(2). Coronary artery obstruction was assessed by the Friesinger score and coronary artery calcification by multislice computed tomography. Serum phosphorus was higher in patients with an Agatston score >10 than in those with an Agatston score <= 10 (3.63 +/- 0.55 versus 3.49 +/- 0.52 mg/dl; p = 0.02). In the patients with Friesinger scores >4, serum phosphorus was higher (3.6 +/- 0.5 versus 3.5 +/- 0.6 mg/dl, p = 0.04) and median intact fibroblast growth factor 23 was lower (40.3 pg/ml versus 45.7 pg/ml, p = 0.01). Each 0.1-mg/dl higher serum phosphate was associated with a 7.4% higher odds of having a Friesinger score >4 (p = 0.03) and a 6.1% greater risk of having an Agatston score >10 (p = 0.01). Fibroblast growth factor 23 was a negative predictor of Friesinger score ( p = 0.002). In conclusion, phosphorus is positively associated with coronary artery calcification and obstruction in patients with suspected coronary artery disease and preserved renal function.