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Bone Reconstruction (bone + reconstruction)
Selected AbstractsOsseous Tissue Engineering With Gene Therapy for Facial Bone Reconstruction,THE LARYNGOSCOPE, Issue 7 2001William H. Lindsey MD Abstract Objective Facial osseous defects remain a major functional and esthetic challenge for the head and neck surgeon. Tissue engineering may provide advantageous alternatives to conventional therapies. The objective of the study was to evaluate the efficacy of gene therapy in the repair of osseous facial defects. Study Design Blinded, controlled, prospective animal experiment. Methods Thirty adult athymic nude rats were divided into five groups of six animals. Three groups were used as control subjects. Two groups were treated with 3.75 × 108 viral particles containing recombinant type 5 adenoviral vectors. One group received viruses that coded for ,-galactosidase production, another received viruses that coded for bone morphogenetic protein (BMP-2) production. After 120 days rats were examined at necropsy with precise planimetry, histological analysis of new bone growth, and radio-densitometric analysis of bone thickness. Results Radio-densitometric measurements showed that BMP-2,treated nude athymic rats had significantly enhanced osseous repair compared with control subjects when evaluated by both radio-densitometry and histological examination. Conclusion Gene therapy,treated, immunosuppressed rodents had an enhanced osteoinductive repair of a dorsal osseous nasal defect. [source] Primary oromandibular reconstruction using free flaps and thorp plates in cancer patients: A 5-year experience,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2003Tito Poli MD Abstract Background. Low-profile second-generation THORP titanium plates combined with soft tissues free flaps (forearm or TRAM) can be used for oromandibular reconstruction in patients with SCC in advanced stage (stage III,IV). Methods. To evaluate long-term stability and possible complications of this reconstructive technique, we recorded, retrospectively, data of 25 patients with posterolateral oromandibular defects after tumor resection collected during a 5-year period. Results. All free flaps were successfully transferred, although eight patients were initially seen with delayed hardware-related reconstructive complications: plate exposure in four patients and plate fracture in four patients. Conclusions. Nowadays, the state-of-the-art treatment for mandibular defects is primary bone reconstruction with bone free flaps, but in selected cases (elderly patients, poor performance status, posterolateral oromandibular defects, soft tissue defects much more important than bone defects) the association with THORP plate-soft tissue free flaps represents a good reconstructive choice. © 2002 Wiley Periodicals, Inc. Head Neck 24: 000,000, 2002 [source] Strategies for Directing the Differentiation of Stem Cells Into the Osteogenic Lineage In Vitro,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2004Boon Chin Heng Abstract A major area in regenerative medicine is the application of stem cells in bone reconstruction and bone tissue engineering. This will require well-defined and efficient protocols for directing the differentiation of stem cells into the osteogenic lineage, followed by their selective purification and proliferation in vitro. The development of such protocols would reduce the likelihood of spontaneous differentiation of stem cells into divergent lineages on transplantation, as well as reduce the risk of teratoma formation in the case of embryonic stem cells. Additionally, such protocols could provide useful in vitro models for studying osteogenesis and bone development, and facilitate the genetic manipulation of stem cells for therapeutic applications. The development of pharmokinetic and cytotoxicity/genotoxicity screening tests for bone-related biomaterials and drugs could also use protocols developed for the osteogenic differentiation of stem cells. This review critically examines the various strategies that could be used to direct the differentiation of stem cells into the osteogenic lineage in vitro. [source] Small-Diameter Implants: Indications and ContraindicationsJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 4 2000MITHRIDADE DAVARPANAH MD ABSTRACT The choice of implant diameter depends on the type of edentulousness, the volume of the residual bone, the amount of space available for the prosthetic reconstruction, the emergence profile, and the type of occlusion. Small-diameter implants are indicated in specific clinical situations, for example, where there is reduced interradicular bone or a thin alveolar crest, and for the replacement of teeth with small cervical diameter. Before using a small-diameter implant, the biomechanical risk factors must be carefully analyzed. Preliminary reports of this type of implant show good short- and medium-term results. CLINICAL SIGNIFICANCE Specific clinical situations indicate the use of small-diameter implants: a reduced amount of bone (thin alveolar crest) and where the replacement tooth requires a small cervical diameter. In some cases, the use of small-diameter implants avoids bone reconstruction. [source] Subcutaneous-induced membranes have no osteoinductive effect on macroporous HA-TCP in vivoJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2009Sylvain Catros Abstract Induced Membranes Technique was first described to enhance bone reconstruction of large osseous defects. Previous in vitro studies established their osteoinductive potential, due to the presence of opteoblasts precursors and to high amounts of growth factors contained within. The purpose of this study was to test in vivo the osteoinductive properties of induced membranes on a macroporous HA-TCP in a nonosseous subcutaneous site. Subcutaneous-induced membranes were obtained in 21 rabbits; 1 month later, the membranes were filled with a biphasic calcium phosphate material composed of 75% hydroxyapatite (HA) and 25% ,-tricalcium phosphate associated or not with autograft. Histological and immunohistochemical studies were performed on membrane biopsies. Undecalcified and decalcified sections were qualitatively and quantitatively analyzed. 45Ca uptake was observed and quantified on the sections using microimager analysis. Dense vascularity was found in the induced membranes. New bone formation was detected in the HA-TCP,+,autograft samples and increased significantly from 3 to 6 months (p,<,0.05). No bone was detected in the biomaterial graft alone in the induced membranes at any time. This study showed that induced membranes placed in a nonosseous site have no osteoinductive properties on a macroporous biphasic calcium phosphate biomaterial. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:155,161, 2009 [source] Portable duplex ultrasonography: A diagnostic and decision-making tool in reconstructive microsurgeryMICROSURGERY, Issue 5 2010Andreas Gravvanis M.D., FEBOPRAS, Ph.D. Unidirectional Doppler is a common diagnostic tool by the Reconstructive Microsurgeons; however, it may generate false signals and surely provides less imaging data as compared to duplex ultrasonography. We have reviewed the use of Portable Duplex Ultrasonography (PDU) in 16 patients who underwent complex soft-tissue/bone reconstruction, aiming to determine its role in the design and management of free tissue transfer. According to our data, there were modifications either of the surgical plan and/or of patient's management, based on PDU findings, in 10 out of 16 patients (62.5%). The use of ultrasound directed to subtle modifications in three patients (19%), but to significant changes of the surgical plan in four patients (25%). Also, the use of ultrasound improved significantly the postoperative management in three patients (19%). Thus, significant impact of PDU in patient's treatment was recorded in 44% of cases. Portable ultrasound represents generally available method for preoperative, intraoperative, and postoperative diagnosis and decision-making in free tissue transfer, hence could replace in the near future the unidirectional Doppler in the hands of Microsurgeons. © 2010 Wiley-Liss, Inc. Microsurgery 30:348,353, 2010. [source] | ||||||||||