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BACKGROUND:With the rapid development of medical technology, computer image technology and the urgent needs of computer-aided clinical teaching, the application of virtual reality technology in oral and maxilofacial anatomy has become an issue of concern. OBJECTIVE:To summarize the application of virtual reality technology in oral and maxilofacial anatomy, thereby providing the better methods for clinical and basic research of oral medicine, laying the foundation for building the digital repository, and realizing the informatization and networking construction. METHODS:A computer-based retrieval was performed by the first author in the CNKI and PubMed databases to search papers related on the virtual reality technology applied in oral and maxilofacial anatomy published between January 2004 and December 2014, using the key words of “tissue engineering, virtual reality, oral and maxilofacial anatomy, digital, 3D reconstruction, multimedia, teeth, skul” in Chinese and English, respectively. According to inclusion and exclusion criteria, 52 papers were included in the final analysis. RESULTS AND CONCLUSION:The application of virtual reality technology in oral and maxilofacial anatomy mainly includes 3D digital model and virtual digital database of human body. 3D medical reconstruction software includes 3D-Doctor and Minics that support the original data sources including continuous fault anatomical images, varieties of image data and 3D scanning data. A variety of virtual reality technologies can successfuly reproduce the tooth, dentition and oral and maxilofacial anatomy, laying the foundation for building the virtual reality platform in oral clinical application and teaching.
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BACKGROUND:Because the content of oral and maxil ofacial anatomy is various and complex, only the traditional way of multimedia cannot display the anatomical structures from multi-angle and al-round. The development of virtual reality technology in oral and maxil ofacial anatomy of three-dimensional reconstruction research is rapid, causes the attention of many scholars, and has become a hot spot. OBJECTIVE:To develop a three-dimensional digital model of tooth, dentition and skul , and establish a multimedia database of oral and maxil ofacial anatomy to facilitate network sharing and information dissemination so as to provide new method for teaching of basic and clinical oral medicine. METHODS:Extracted teeth with intact crown and root, dentition and skul were chosen. Each specimen was taken at horizontal and vertical direction by the camera in the center of turntable. Al the images obtained were treated using Photoshop CS5 for dressing and compression. The image data were input into The VR Worx system, fol owed by parameters and hotspots setting and the compression. Final y, the three-dimensional digital models were reconstructed and output with QuickTime VR format into disk. RESULTS AND CONCLUSION:Three-dimensional digital models of tooth and skul were constructed with photography and the VR Worx 2.6 software, which could faithful y reproduce the anatomical characteristics of teeth, dentition and skul s, and facilitate researchers to rotate and scale for observation. Also, it was easy for hotspot-marking. On the platform of digital photography and The VR Worx software, it is feasible to establish the three-dimensional digital model of tooth and skul . This approach is the entity reconstruction, and the reconstructed model appears clear, vivid, and is easy to be saved and promoted.
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<p><b>OBJECTIVE</b>This research aims to study the changes in pain threshold and glial cell line-derived neurotrophic factor (GDNF) in a Sprague Dawley (SD) rat model oftrigeminal neuralgia.</p><p><b>METHODS</b>A total of 36 male SD rats were randomly divided into three groups: operative, sham-operative, and control. In the operative group, a chronic constriction injury (CCI) was caused by placing loose chromic gut ligatures around the right infraorbital nerve (ION). In the sham-operative group, the right ION was subjected to the same procedure, but without ligation. In the control group, the right ION was not subjected to any treatment. The pain thresholds of the three groups were recorded at different times after the operation. The GDNF expression in each group was analyzed via immunohistochemical staining.</p><p><b>RESULTS</b>An allodynia to mechanical stimulation in the region of the ligated ION was observed starting on the 2nd week after operation. Pain thresholds started to increase gradually from the 6th week and returned to the original level at the 10th to 12th week after operation. Cells that expressed the GDNF markedly increased in number in the operative group with changes observed at different times.</p><p><b>CONCLUSION</b>We use chronic constriction injury to the infraorbital nerve (CCI-ION) to establish a trigeminal neuralgia-like animal model in SD rats. GDNF may play a role in regulating pain by promoting the restoration and regeneration of nerve fibers.</p>