Dry skull positioning device for extra-oral radiology and cone-beam CT

Extra-oral radiographs of dry skulls on scientific or forensic context have head position as a critical procedure. The aims of this article are to present a multi-purposed head-positioning device, and to describe the new method of image acquirement using the device to adequately keep the head in a correct and safe position during radiological or tomographic exam. The design was created from an average-sized skull and then tested in 20 others with different morphologies, sizes, weights, and structural state of preservation. A series of digital and analog orthopantomographies followed by a cone-beam computer tomography were obtained to assure that the correct positioning standards and anatomical visualization were achievable. The developed device properly kept adult skulls in position for all extra-oral radiographic exams, providing to operators a secure and facilitated way to achieve the proper position standards. The device did not impair the visualization of the anatomical structures neither on radiographs nor in cone-beam computer tomography.     

The effects of low-level laser irradiation on bone tissue in diabetic rats

Diabetes mellitus (DM) leads to a decrease in bone mass and increase the risk of osteoporosis and in this context, many treatments have shown to accelerate bone metabolism. It seems that low-level laser therapy (LLLT) is able of stimulating osteoblast activity and produced increased biomechanical properties. However, its effects on bone in diabetic rats are not fully elucidated. The aim of this study was to evaluate the effects of LLLT on bone formation, immunoexpression of osteogenic factors, biomechanical properties and densitometric parameters in diabetic rats. Thirty male Wistar rats were randomly distributed into three experimental groups: control group, diabetic group, and laser-treated diabetic group. DM was induced by streptozotocin (STZ) and after 1 week laser treatment started. An 830-nm laser was used, performed for 18 sessions, during 6 weeks. At the end of the experiment, animals were euthanized and tibias and femurs were defleshed for analysis. Extensive resorptive areas as a result of osteoclasts activity were noticed in DG when compared to control. Laser-treated animals showed an increased cortical area. The immunohistochemical analysis revealed that LLLT produced an increased RUNX-2 expression compared to other groups. Similar RANK-L immunoexpression was observed for all experimental groups. In addition, laser irradiation produced a statistically increase in fracture force, bone mineral content (BMC) and bone mineral density compared to DG. The results of this study indicate that the STZ model was efficient in inducing DM 1 and producing a decrease in cortical diameter, biomechanical properties and in densitometric variables. In addition, it seems that LLLT stimulated bone metabolism, decreased resorptive areas, increased RUNX-2 expression, cortical area, fracture force, BMD, and BMC. Further studies should be developed to provide additional information concerning the mechanisms of action of laser therapy in diabetic bone in experimental and clinical trials.     

Epidemiology and Control of Child Toxocariasis in the Western Brazilian Amazon – A Population-Based Study

Toxocara spp. infection and the seroconversion rate in the Amazon have been poorly investigated. This study analyzed individual and household-level risk factors for the presence of IgG antibodies to Toxocara spp. in urban Amazonian children over a period of 7 years and evaluated the seroconversion rates over a 1-year follow-up. In children < 59 months of age, the overall prevalence rate was 28.08% in 2003 and 23.35% in 2010. The 2010–2011 seroconversion rates were 13.90% for children 6–59 months of age and 12.30% for children 84–143 months of age. Multilevel logistic regression analysis identified child age, previous wheezing, and current infection with hookworm as significant associated factors for Toxocara spp. seropositivity in 2003. In 2010, age, previous helminthiasis, and having a dog were associated with seropositivity, whereas having piped water inside the household was a protective factor. Control programs mainly need to target at-risk children, water quality control, and animal deworming strategies.