983 resultados para radiographic zooming
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Biotecnologia Animal - FMVZ
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Pós-graduação em Biotecnologia Animal - FMVZ
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PURPOSE: To investigate the facial symmetry of high and low dose methotrexate (MTX) treated rats submitted to experimentally displaced mandibular condyle fracture through the recording of cephalometric measurements. METHODS: One hundred male Wistar rats underwent surgery using an experimental model of right condylar fracture. Animals were divided into four groups: A - saline solution (1mL/week); B - dexamethasone (DEX) (0,15mg/Kg); C - MTX low dose (3 mg/Kg/week); D - MTX high dose (30 mg/Kg). Animals were sacrificed at 1, 7, 15, 30 and 90 days postoperatively (n=5). Body weight was recorded. Specimens were submitted to axial radiographic incidence, and cephalometric mensurations were made using a computer system. Linear measurements of skull and mandible, as well as angular measurements of mandibular deviation were taken. Data were subjected to statistical analyses among the groups, periods of sacrifice and between the sides in each group (alpha=0.05). RESULTS: Animals regained body weight over time, except in group D. There was reduction in the mandibular length and also changes in the maxilla as well as progressive deviation in the mandible in relation to the skull basis in group D. CONCLUSION: Treatment with high dose methotrexate had deleterious effect on facial symmetry of rats submitted to experimentally displaced condylar process fracture.
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Skeletal tissues of 49 humpback whales Megaptera novaeangliae that stranded between 2002 and 2011 along the Abrolhos Bank seashore and its adjacent waters in Brazil were studied. Twelve (24.5%) animals presented pathological changes in one or more bones. Degenerative changes and developmental malformations were most frequent (10.2% each), followed by inflammatory/infectious and traumatic lesions (8.2% each). Infectious diseases led to severe lesions of the caudal vertebrae of 2 whales. In one of these individuals, the lesions involved 6 caudal vertebrae, leading to ankylosis of 3 vertebrae. Degenerative changes were observed in the vertebral columns of 3 animals, involving the joints of 13 ribs of 1 individual, and in the humerus of 1 whale. Traumatic lesions, such as osseous callus in the ribs, were observed in 4 animals. In 1 whale, the rib showed severe osteomyelitis, possibly resulting from the infection of multiple fractures. Developmental abnormalities such as spina bifida on 3 cervical vertebrae of 1 whale, fusion of spinal processes on thoracic vertebrae of 1 individual and fusion of the first 2 ribs unilaterally or bilaterally in 4 animals were found. Chronic infectious conditions found in the axial skeleton may have restrained spinal mobility and had detrimental effects on the general health of the animals, contributing to stranding and death. To our knowledge, this is the first systematic study on skeletal lesions in stranded humpback whales.
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This study analyzed the effects of unilateral detachment of the temporal muscle and coronoidotomy on facial growth in young rats. Thirty one-month-old Wistar rats were distributed into three groups: detachment, coronoidotomy and sham-operated. Under general anesthesia, unilateral detachment of the temporal muscle was performed for the detachment group, unilateral coronoidotomy was performed for the coronoidotomy group, and only surgical access was performed for the sham-operated group. The animals were sacrificed at three months of age. Their soft tissues were removed, and the mandible was disarticulated. Radiographic projections-axial views of the skulls and lateral views of hemimandibles-were taken. Cephalometric evaluations were performed, and the values obtained were submitted to statistical analyses. There was a significant homolateral difference in the length of the premaxilla, height of the mandibular ramus and body, and the length of the mandible in all three groups. However, comparisons among the groups revealed no significant differences between the detachment and coronoidotomy groups for most measurements. It was concluded that both experimental detachment of the temporal muscle and coronoidotomy during the growth period in rats induced asymmetry of the mandible and affected the premaxilla.
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Objective To assess several baseline risk factors that may predict patellofemoral and tibiofemoral cartilage loss during a 6-month period. Methods For 177 subjects with chronic knee pain, 3T magnetic resonance imaging (MRI) of both knees was performed at baseline and followup. Knees were semiquantitatively assessed, evaluating cartilage morphology, subchondral bone marrow lesions, meniscal morphology/extrusion, synovitis, and effusion. Age, sex, and body mass index (BMI), bone marrow lesions, meniscal damage/extrusion, synovitis, effusion, and prevalent cartilage damage in the same subregion were evaluated as possible risk factors for cartilage loss. Logistic regression models were applied to predict cartilage loss. Models were adjusted for age, sex, treatment, and BMI. Results Seventy-nine subregions (1.6%) showed incident or worsening cartilage damage at followup. None of the demographic risk factors was predictive of future cartilage loss. Predictors of patellofemoral cartilage loss were effusion, with an adjusted odds ratio (OR) of 3.5 (95% confidence interval [95% CI] 1.39.4), and prevalent cartilage damage in the same subregion with an adjusted OR of 4.3 (95% CI 1.314.1). Risk factors for tibiofemoral cartilage loss were baseline meniscal extrusion (adjusted OR 3.6 [95% CI 1.310.1]), prevalent bone marrow lesions (adjusted OR 4.7 [95% CI 1.119.5]), and prevalent cartilage damage (adjusted OR 15.3 [95% CI 4.947.4]). Conclusion Cartilage loss over 6 months is rare, but may be detected semiquantitatively by 3T MRI and is most commonly observed in knees with Kellgren/Lawrence grade 3. Predictors of patellofemoral cartilage loss were effusion and prevalent cartilage damage in the same subregion. Predictors of tibiofemoral cartilage loss were prevalent cartilage damage, bone marrow lesions, and meniscal extrusion.
Human Bone Morphogenetic Protein-2 Use for Maxillary Reconstruction in Cleft Lip and Palate Patients
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Background: The conventional methods of maxillary alveolar reconstruction in patient with cleft are the periosteoplasty and autologous bone grafting. As an important alternative of bone substitution, there is the recombinant human bone morphogenetic protein-2 (rhBMP-2). This study compares the rhBMP-2 with periosteoplasty and autologous bone grafting. Methods: Patients with cleft and alveolar defect were divided into 3 groups of 6 patients who underwent to autologous iliac crest bone grafting, resorbable collagen sponge with rhBMP2, and periosteoplasty, respectively. The analysis was performed through computed tomographic scan preoperatively and at months 3, 6, and 12 postoperatively. The variables analyzed were the alveolar defect volume, formed bone volume, bone formation rate, maxillary height repair rate, and the formed bone density mean. Results: The formed bone volume was similar comparing the bone graft and BMP groups at 1-year postoperative analysis (P = 0.58). Both of them had the formed bone volume significantly larger than the periosteoplasty group at 3 and 6 months postoperatively. In this last group, the 1-year follow-up was canceled because the bone formation was insufficient. The bone formation rate, the maxillary height repair rate, and the mean of density of the formed bone were similar in the bone graft and BMP groups at 1-year follow-up with P values of 0.93, 0.90, and 0.81, respectively. Conclusions: The amount of formed bone in the periosteoplasty group was insufficient. There was no difference among the bone graft and rhBMP-2 therapy considering the parameters analyzed.
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Purpose: This prospective randomized matched-pair controlled trial aimed to evaluate marginal bone levels and soft tissue alterations at implants restored according to the platform-switching concept with a new inward-inclined platform and compare them with external-hexagon implants. Materials and Methods: Traditional external-hexagon (control group) implants and inward-inclined platform implants (test group), all with the same implant body geometry and 13 mm in length, were inserted in a standardized manner in the posterior maxillae of 40 patients. Radiographic bone levels were measured by two independent examiners after 6, 12, and 18 months of prosthetic loading. Buccal soft tissue height was measured at the time of abutment connection and 18 months later. Results: After 18 months of loading, all 80 implants were clinically osseointegrated in the 40 participating patients. Radiographic evaluation showed mean bone losses of 0.5 +/- 0.1 mm (range, 0.3 to 0.7 mm) and 1.6 +/- 0.3 mm (range, 1.1 to 2.2 mm) for test and control implants, respectively. Soft tissue height showed a significant mean decrease of 2.4 mm in the control group, compared to 0.6 mm around the test implants. Conclusions: After 18 months, significantly greater bone loss was observed at implants restored according to the conventional external-hexagon protocol compared to the platform-switching concept. In addition, decreased soft tissue height was associated with the external-hexagon implants versus the platform-switched implants. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:927-934.
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The objective of the current study was to assess the outcome of the alveolar bone grafting (ABG) in patients with cleft palate. Thirty-one patients with complete unilateral cleft lip and palate were prospectively divided into 2 groups according to the timing of surgery: (1) secondary ABG (SABG), undertaken during mixed dentition (n = 16); and (2) tertiary ABG (TABG), undertaken during permanent dentition (n = 15). Septum height was assessed using cone beam computed tomography in 3 views (buccal, intermediate, palatal) and classified according to the modified Bergland Index, which scores the results into 5 types according to the height of the neoformed bone septum (excellent: septum with a normal height; good: septum with minor deficiency; regular: marginal defect of >25% of the root length; bad: bone deficiency on the nasal aspect; and failure). In the SABG group, 6 to 12 months postoperatively, 75% of the patients were classified as having excellent/good conditions and 25% as having regular/bad conditions. No patients were observed as having failure conditions. In the TABG group, 53% of the patients were classified as having excellent/good, 21% were classified as having regular/bad conditions, and 26% were classified as having failure conditions. Significantly better outcomes were observed for the SABG group when compared with the TABG group. In conclusion, the age at which ABG is performed is a factor that impacts on the surgical outcome. Specifically, increasing age is associated with worse outcomes.
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Introduction: The aim of the present study was to evaluate the physicochemical properties of a bioceramic root canal sealer, Endosequence BC Sealer. Radiopacity, pH, release of calcium ions (Ca2+), and flow were analyzed, and the results were compared with AH Plus cement. Methods: Radiopacity and flow were evaluated according to ISO 6876/2001 standards. For the radiopacity analysis, metallic rings with 10-mm diameter and 1-mm thickness were filled with cements. The radiopacity value was determined according to radiographic density (mm Al). The flow test was performed with 0.05 mL of cement placed on a glass plate. A 120-g weight was carefully placed over the cement. The largest and smallest diameters of the disks formed were measured by using a digital caliper. The release of Ca2+ and pH were measured at periods of 3, 24, 72, 168, and 240 hours with spectrophotometer and pH meter, respectively. Data were analyzed by analysis of variance and Tukey test (P < .05). Results: The bioceramic endodontic cement showed radiopacity (3.84 mm Al) significantly lower than that of AH Plus (6.90 mm Al). The pH analysis showed that Endosequence BC Sealer showed pH and release of Ca2+ greater than those of AH Plus (P < .05) during the experimental periods. The flow test revealed that BC Sealer and AH Plus presented flow of 26.96 mm and 21.17 mm, respectively (P < .05). Conclusions: Endosequence BC Sealer showed radiopacity and flow according to ISO 6876/2001 recommendations. The other physicochemical properties analyzed demonstrated favorable values for a root canal sealer. (J Endod 2012;38:842-845)
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Background: In the literature, there are several experimental models that induce scoliosis in rats; however, they make use of drugs or invasive interventions to generate a scoliotic curve. Objectives: To design and apply a non-invasive immobilization model to induce scoliosis in rats. Methods: Four-week old male Wistar rats (85 +/- 3.3 g) were divided into two groups: control (CG) and scoliosis (SG). The animals in the SG were immobilized by two vests (scapular and pelvic) made from polyvinyl chloride (PVC) and externally attached to each other by a retainer that regulated the scoliosis angle for twelve weeks with left convexity. After immobilization, the abdominal, intercostal, paravertebral, and pectoral muscles were collected for chemical and metabolic analyses. Radiographic reports were performed every 30 days over a 16-week period. Results: The model was effective in the induction of scoliosis, even 30 days after immobilization, with a stable angle of 28 +/- 5 degrees. The chemical and metabolic analyses showed a decrease (p<0.05) in the glycogenic reserves and in the relationship between DNA and total protein reserves of all the muscles analyzed in the scoliosis group, being lower (p<0.05) in the convex side. The values for the Homeostatic Model Assessment of Insulin Resistance indicated a resistance condition to insulin (p<0.05) in the scoliosis group (0.66 +/- 0.03), when compared to the control group (0.81 +/- 0.02). Conclusions: The scoliosis curvature remained stable 30 days after immobilization. The chemical and metabolic analyses suggest changes in muscular homeostasis during the induced scoliosis process.
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Regional odontodysplasia is a rare and significant dental malformation. It is a dental alteration of unknown etiology, involving both mesodermal and ectodermal dental components, which present clinical, radiographic, and histologic features. This article reports a clinical case of a 10-month-old child who was diagnosed with regional odontodysplasia in the maxilla, confirmed by radiographic examination, with a follow-up of 5 years. The clinical, radiographic, and histologic features were reviewed.
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This study investigated the immunodetection of PTCH in epithelial components of dental follicles associated with impacted third molars without radiographic signs of pathosis. One hundred and five specimens of dental follicles associated with impacted third molars with incomplete rhizogenesis (between Nolla's stage 6 and 9) were surgically removed from 56 patients. Epithelial cell proliferation was determined by using immunohistochemical labeling. Statistical analysis was performed using Fisher exact test and a level of significance of 5%. Of the 105 dental follicles collected, 3 were PTCH-positive. The specimens with squamous metaplasia and epithelial hyperplasia had higher rates of positivity for PTCH, as well as those with active remnants of odontogenic epithelium. This study suggests that the odontogenic cells of the dental follicle might be proliferating during the rhizogenesis, while the squamous metaplasia and hyperplasia of the epithelial lining and proliferative odontogenic epithelial rests show the differentiation potential of dental follicles.