Oliverbyskov7607
3±3.2) (P0.05). Conclusions The application of MR technology achieved a better teaching effect, which could help residents to deeply understand the methods of fibular flap preparation, and showed a broad application prospect.A series of regulations and policies for Dental Practitioner Qualification were issued during modern times (1906-1949) in China from local to national levels, in which the certification for qualification had been largely based on dental education and training experiences. The present article reviews the evolution and progression of dental practitioner qualification management, as well as its relationship to dental education before 1949, which may hopefully provide a historical background for the development of modern dentistry and enhance the understanding of the current management process for dental practitioner qualifications in China.Objective To study the relationship between zoledronic acid (ZOL) and vascular endothelial growth factor (VEGF) conformation so as to reveal the mechanism of bisphosphonates inhibiting angiogenesis. Methods The binding structures of ZOL and VEGF were preprocessed and the molecular dockings were simulated through AutoDockTools, Discovery studio4 and AutoDockVina. The best binding conformation was accurately screened. The effects of various concentrations of ZOL (group A was 0 μmol/L, groups B, C and D were 25, 50 and 100 μmol/L, respectively) on human umbilical vein endothelial cell (HUVEC) proliferation, angiogenesis and angiogenic molecules were detected by using cell counting kit-8 (CCK-8) in vivo and in vitro angiogenesis, immunofluorescence and Western blotting. Results There was a ZOL binding site on the target protein VEGF conformation. The affinity was -5.2 kcal/mol. This binding site consisted of the hydrophobic region composed of amino acids Cys26, 51, 57, etc. SCH66336 ic50 and the hydrogen bond binding region of and D [(0.68±0.09), (0.55±0.06) and (0.43±0.08), respectively] were significantly lower than that in group A (0.96±0.04) (P less then 0.05). Conclusions ZOL could inhibit cell proliferation, in vivo and in vitro vascularization and expression of VEGF/HIF-1α. The binding site of ZOL with the conformation of VEGF was located in the hydrophobic region and hydrogen-bonding region of amino acids. Designing an antagonist targeting this site might potentially alleviate the effect of ZOL in inhibiting angiogenesis.Objective To investigate the effect of low dose lipopolysaccharide (LPS)-treated human periodontal ligament stem cells (HPDLSC) on the expression of macrophage pro-inflammatory factors and the mechanism involved. Methods The primary HPDLSCs were obtained from healthy third molar periodontal ligament tissue. Phosphate buffer saline (PBS), 100 μg/L or 10 mg/L of LPS were used to treat HPDLSCs for 48 h, and their conditioned media were respectively co-cultured with THP-1-derived macrophages for 48 h. The corresponding experimental groups were PBS-treated HPDLSC-derived conditioned medium (CM-C) group, low dose LPS-treated HPDLSC-derived conditioned medium (CM-L) group, and high dose LPS-treated HPDLSC-derived conditioned medium (CM-H) group. Quantitative real-time PCR was performed to explore the mRNA expressions of macrophage interleukin (IL)-6, IL-8, IL-12, tumor necrosis factor-α (TNF-α) in the CM-C, CM-L and CM-H groups, and the expressions of nuclear factor (erythroid-derived 2)-like 2 (NRF2), glutamate-cysregulate oxidative stress response through activating the NRF2 signaling pathway of macrophages and further downregulating the expressions of macrophage pro-inflammatory factors.Objective To develop an artificial intelligence system for detecting dental plaque on permanent teeth and find the influenced factors. Methods Photos of the labial or buccal surfaces of the permanent teeth were taken by using an intraoral camera (1 280×960 pixels; TPC Ligang, Shenzhen, China) before and after applying the plaque-disclosing agent (Cimedical, Japan) in 25 volunteers [12 males, 13 femals, aged (23±3) years] recruided in accordance with the inclusion criteria from the students of Peking University School of Stomatology from October 2018 to June 2019. A total of 549 groups of photos were captured and then divided into a training dataset containing 440 groups of photos and a test dataset including 109 groups of photos. The scopes of teeth and dental plaque on photos were labeled using LabelMe (Windows 3.2.1, MIT, U S A). A DeepLab based deep learning system was designed for the intelligent detection of dental plaque on permanent teeth. The mean intersection over union (MIoU) was employed to indicatrcentage of plaque is -0.551. Conclusions In the present study, an artificial intelligence system was built to detect dental plaque area on tooth photos collected by family intraoral camera. The system showed the ability to detect the dental plaque of permanent teeth. The more complex the marginal line of dental plaque and higher the percentage of dental plaque are, the lower the accuracy of plaque recognition is.Objective To summarize the etiological characteristics and clinical treatment effects of 17 patients with medication-related osteonecrosis of the jaw (MRONJ). Methods The clinical data of 17 patients with MRONJ admitted to the Department of Oral and Maxillofacial Surgery, the First People's Hospital of Jinzhong, Shanxi Province, from July 2016 to December 2019 were retrospectively analyzed, including 9 males and 8 females, aged (63.6±9.6) years old (43-82 years old). Descriptive analysis of the primary disease, onset factors, site of disease, clinical manifestations, treatment methods, and treatment effects was conducted through follow-up for at least 1 year. Results Among the primary diseases of the 17 cases, 12 were malignant tumors, and 5 were osteoporosis. There were 13 cases with a history of a trigger event (tooth extraction or unsuited removable denture). Six cases occurred in the maxilla, 10 cases occurred in the mandible, and 1 case involved both the upper and lower jaws. For the most common medication used, bisphosphonate was used in 16 cases including 5 cases with concomitant use of angiogenesis-inhibiting drugs. There was 1 case resulted from receptor activator of NF-κB ligand (RANKL) monoclonal antibody application. The duration of medication application was (10.1±3.9) months (3-18 months). All 17 cases were treated surgically. Totally 15 patients healed well after surgical treatment and the other 2 patients, who had poor soft tissue healing after surgery, healed well after a second operation. Conclusions Tooth extraction might be a major trigger factor for the onset of MRONJ in the mandible. The disease was more possibly occured in the mandible than in the maxilla. Appropriate surgical treatment could achieve a good clinical outcome.