Ossifying fibroma: A systemic review
ABSTRACT The aim was to evaluate the principal features of ossifying fibroma (OF) by systematic review (SR), and to compare their frequencies among four global groups.
The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of OFs that occurred in a series in the reporting authors' caseload were considered. All cases were confirmed fibro-osseous lesions histopathologically. The SR-included series had also to have used radiographs.
Of the 64 reports (including the Hong Kong report) considered, 32 reports and a total of 781 cases were included in the SR. Ten SR-included series were in languages other than English. OF affected females more frequently, but was three times more prevalent in the mandible. The mean age at first presentation was 31 years. The decade with the greatest frequency was the fourth. Females were in the majority except in the first decade. The main symptom in 66% of all SR-included cases was swelling (including deformation of the jaws). 31% were found incidentally. 84% of cases displayed buccolingual expansion; half of the mandibular cases exhibited downward displacement of the lower border of the mandible and 90% of maxillary cases involved the maxillary antrum. Only 28% of reports included follow-up; 12% of cases recurred or were reactivated.
Although long-term follow-up of large series that would have revealed the long-term outcomes of OF was lacking, a 12% recurrence rate is clinically significant and suggests that OFs should be considered for long-term follow-up.
- SourceAvailable from: Ruili Yang
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- "Currently, complete surgical removal of the affected bone is widely recommended in the management of OF. However, patients often suffer from difficult reconstruction with postsurgical disfigurement, high and unpredictable recurrence rates, and major loss of vital tissues (MacDonald-Jankowski, 2009). Therefore, more appropriate treatments for OF are needed. "
ABSTRACT: Abnormal stem cell function makes a known contribution to many malignant tumors, but the role of stem cells in benign tumors is not well understood. Here, we show that ossifying fibroma (OF) contains a stem cell population that resembles mesenchymal stem cells (OFMSCs) and is capable of generating OF-like tumor xenografts. Mechanistically, OFMSCs show enhanced TGF-β signaling that induces aberrant proliferation and deficient osteogenesis via Notch and BMP signaling pathways, respectively. The elevated TGF-β activity is tightly regulated by JHDM1D-mediated epigenetic regulation of thrombospondin-1 (TSP1), forming a JHDM1D/TSP1/TGF-β/SMAD3 autocrine loop. Inhibition of TGF-β signaling in OFMSCs can rescue their abnormal osteogenic differentiation and elevated proliferation rate. Furthermore, chronic activation of TGF-β can convert normal MSCs into OF-like MSCs via establishment of this JHDM1D/TSP1/TGF-β/SMAD3 autocrine loop. These results reveal that epigenetic regulation of TGF-β signaling in MSCs governs the benign tumor phenotype in OF and highlight TGF-β signaling as a candidate therapeutic target.Cell stem cell 11/2013; 13(5):577-89. DOI:10.1016/j.stem.2013.08.010 · 22.15 Impact Factor
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ABSTRACT: The More Electric Initiative demands (MEI) high temperature and high power electronic circuits for use in power management and distribution in advanced aircraft systems. In an attempt to develop electronic power devices for high temperature application, SiC diodes were performance mapped for dynamic characterization in the temperature range of 25°C to 300°C. Similar high temperature dynamic characterization was performed on SiC MOSFETs in the temperature range of 25°C to 300°C. In order to compare the advantages of enhanced SiC device performance at elevated temperatures over Si devices, Si and SiC devices were studied in a buck type DC/DC converter circuit. The present research is geared towards the investigation of thermal effects at high temperatures on the performance characteristics of the buck converter circuit. SiC devices are capable of operating at higher voltages and temperatures when compared to Si devices. To investigate these advantages, Si MOSFETs and Si diodes were used in a Si based buck converter circuit at elevated temperatures. A Si MOSFET and SiC diode were initially used in the buck converter circuit. Performance characteristics of this converter circuit were generated at elevated temperatures. The converter utilizes a Si MOSFET with a Si or SiC Schottky diode, Schottky diodes were preferred over p-n diodes as the reduced on-voltage results in improved efficiency. Performance characteristics were measured to determine the effect of temperature of the on-resistance of the MOSFET, efficiency and DC voltage transfer function (M<sub>vdc</sub>) of the converterEnergy Conversion Engineering Conference, 1997. IECEC-97., Proceedings of the 32nd Intersociety; 01/1997
Conference Paper: Analysis of vectorial 3D problems with arbitrary boundary inwaveguide[Show abstract] [Hide abstract]
ABSTRACT: The paper describes a new integral equation method to solve 3D arbitrary discontinuity problems in a waveguide, where the potential type dyadic Green's function of the waveguide is used. Combining the network method and boundary element method, the generalized network parameters can be obtained directly. This method has a small memory size requirement and can achieve high accuracyMicrowave Conference Proceedings, 1997. APMC '97, 1997 Asia-Pacific; 01/1998