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Several devices used to harvest stem/progenitor cells from bone marrow are available to clinicians. This study compared three devices measuring stem cell yields and correlating those yields to bone regeneration. A flexible forward aspirating system Marrow Marxman (MM), a straight needle aspirating on withdrawal system Marrow Cellutions (MC), and a straight needle aspirating on withdrawal and centrifuging the aspirate (BMAC) were compared in a side-to-side patient comparison, as well as tissue engineered bone grafts. The FlexMetric system (MM) produced greater CFU-f values compared to the straight needle (MC) Δ = 1083/ml, p < 0.001 and 1225/ml, p < 0.001 than the BMAC system. This increased stem/progenitor cell yield also translated into a greater radiographic bone density at 6 months Δ = 88.3 Hu, p ≤ 0.001 versus MC and Δ = 116.7, p < 0.001 versus BMAC at 6 months and Δ = 72.2, p < 0.001 and Δ = 93.3, p < 0.001 at 9 months respectively. The increased stem/progenitor cell yield of the MM system clinically translated into greater bone regeneration as measured by bone volume p < 0.014 and p < 0.001 respectively, trabecular thickness p < 0.007 and p < 0.002 respectively, and trabecular separation p = 0.011 and p < 0.001. A flexible bone marrow aspirator produces higher yields of stem/progenitor cells. Higher yields of stem/progenitor cells translate into greater bone regeneration in tissue engineering. Flexmetric technology produces better bone regeneration due to a forward aspiration concept reducing dilution from peripheral blood and its ability to target lining cells along the inner cortex. Centrifugation systems are not required in tissue engineering procedures involving stem/progenitor cells due to nonviability or functional loss from g-forces.

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Osteoradionecrosis (ORN) is a well-known and usually late complication of radiation therapy in the treatment of head and neck cancer. Although the therapy can be life extending, it also produces tissue toxicity in ipsilateral and contralateral tissues in an acute and chronic fashion. In the most severe cases of ORN, such as the one presented in this report, bilateral disease results in the need for total mandibulectomy and creates a tremendous reconstructive challenge. The advent of microvascular surgery and free tissue transfer has caused an evolution of the management protocol for severe ORN cases. This report describes a unique case of total mandibulectomy with synchronous reconstruction using a single vascularized fibula osteocutaneous flap with subsequent dental implant reconstruction and prosthetic rehabilitation.

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PURPOSE: The advent of microvascular free tissue transfer has provided the reconstructive surgeon with an enormous array of treatment options for reconstruction of large head and neck defects. However, when indicated by defect size, the need for more than 1 flap not only increases surgical complexity but also patient morbidity. The combination of the anterolateral thigh (ALT) flap and the tensor fascia latae (TFL) flap can be used to reconstruct such complex head and neck defects, thereby minimizing any additional morbidity that would be imposed by an additional flap harvest site. The present study reports on the use of the combined ALT-TFL flap to reconstruct large and complex head and neck defects. MATERIALS AND METHODS: A retrospective chart review was conducted of all microvascular head and neck reconstructions performed by the Maxillofacial Tumor and Reconstructive Surgery Service at the University of Miami/Jackson Health System (Miami, FL) from 2013 through 2016. Inclusion criteria for the study were head and neck defects at least 20 m × 10 cm and reconstruction with soft tissue flaps using perforating vasculature to the TFL and ALT vascular territories. Other study data included disease history, location of defect, flap size, recipient vessels, harvest time, ischemia time, surgical complications, and overall flap survival. RESULTS: Seven patients met the inclusion criteria. Five patients were treated for the diagnosis of stage III osteoradionecrosis and 2 patients underwent reconstruction in conjunction with ablative surgery for head and neck carcinoma. All 7 patients underwent successful head and neck reconstructions using the ALT-TFL flap. There was no partial or total flap failure. One patient had a wound healing complication at the donor site that did not require surgical intervention. CONCLUSION: Reconstruction of a large head and neck soft tissue defect with a combined ALT-TFL flap is a reliable method with minimal donor site morbidity and no major postoperative complications. This combined flap should be considered when the defect size extends beyond the bounds allowed by the ALT flap alone.

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Researchers have suggested different models to describe the feeling of presence. Most of them imply that presence is some kind of alternate state. Research conducted in our research team lead us to consider presence simply like a very powerful perceptual illusion, with the addition of challenging the meaning given to the place where the user actually is (i.e., being "there"). The aim of this study is to investigate the neural correlates of the illusion of presence in VR. Five right-handed adults were scanned in the fMRI and were immersed in two conditions: high and low presence, where the exact same stimulus was presented to participants during each condition but the context (narrative) provided differed significantly. Results show a clear, specific and statistically significant involvement of the parahippocampal area, the brain responsible for giving contextual meaning of places.

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