Preliminary application of three dimensional printing surgical guide plate in orthognathic surgery for partial mandibular deformities / 中华医学美学美容杂志

Objective To evaluate the effectiveness of computer aided design (CAD) and three bit printing in the management of orthognathic surgery.Methods A total of 5 cases of patients with jaw deformity were involved in this study;jaw teeth and CT scanning laser scanning hefore surgery,virtual surgery design of 3D reconstruction and fusion data were analyzed,according to the design scheme of double jaw surgery combined with genioplasty;design and 3D printing of maxillary Le Fort Ⅰ osteotomy,genioplasty titanium alloy resin osteotomy and positioning guide,sagittal split ramus osteotomy by 3D printing and plate technology were used in this approach.The postoperative results were compared with the surgical planning by three-dimensional measurement and statistical analysis.Results When the operation guide plate was applied smoothly,the maximum error for maxilla was 1.2 mm (0.3-1.2 mm),and the maximum error for genioplasty was 1.7 mm,(0.5-1.7 mm),and the mean error was less than 1 mm.Follow-up for 12 months showed no adverse reaction.Conclusions Three dimensional printing surgical guide plate can accurately provide the osteotomy information,effectively control the jaw movement,and improve the orthognathic surgery accuracy of patients with partial jaw deformity.

Overexpression of Dlx2 enhances osteogenic differentiation of BMSCs and MC3T3-E1 cells via direct upregulation of Osteocalcin and Alp / 国际口腔科学杂志·英文版

Genetic studies have revealed a critical role of Distal-homeobox (Dlx) genes in bone formation, and our previous study showed that Dlx2 overexpressing in neural crest cells leads to profound abnormalities of the craniofacial tissues. The aim of this study was to investigate the role and the underlying molecular mechanisms of Dlx2 in osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) and pre-osteoblast MC3T3-E1 cells. Initially, we observed upregulation of Dlx2 during the early osteogenesis in BMSCs and MC3T3-E1 cells. Moreover, Dlx2 overexpression enhanced alkaline phosphatase (ALP) activity and extracellular matrix mineralization in BMSCs and MC3T3-E1 cell line. In addition, micro-CT of implanted tissues in nude mice confirmed that Dlx2 overexpression in BMSCs promoted bone formation in vivo. Unexpectedly, Dlx2 overexpression had little impact on the expression level of the pivotal osteogenic transcription factors Runx2, Dlx5, Msx2, and Osterix, but led to upregulation of Alp and Osteocalcin (OCN), both of which play critical roles in promoting osteoblast maturation. Importantly, luciferase analysis showed that Dlx2 overexpression stimulated both OCN and Alp promoter activity. Through chromatin-immunoprecipitation assay and site-directed mutagenesis analysis, we provide molecular evidence that Dlx2 transactivates OCN and Alp expression by directly binding to the Dlx2-response cis-acting elements in the promoter of the two genes. Based on these findings, we demonstrate that Dlx2 overexpression enhances osteogenic differentiation in vitro and accelerates bone formation in vivo via direct upregulation of the OCN and Alp gene, suggesting that Dlx2 plays a crucial role in osteogenic differentiation and bone formation.

Stability of joint orthognathic and orthodontic treatment for dental-facial deformity in patients with cleft lip and palate / 中华医学美学美容杂志

Objective To evaluate the skeletal stability of joint orthognathic and orthodontic treatment for cleft patients compared with non-cleft patients.Methods Fifteen cleft patient diagnosed with dental facial deformities underwent joint orthognathic and orthodontic treatment.Cephalometric analysis was carried out at T0 (before treatment),T1 (2 weeks after surgery),T2 (6 months after surgery) and T3 (24 months after surgery).The comparison of maxillary anterior-posterior and superiorinferior movement was performed with non-cleft orthognathic group (n =15) at the same follow-up time point.Results The maxilla was move forward for (3.8 ± 1.5) mm and downward for (2.4± 0.8) mm of cleft group.The relapse distance was (1.2±-0.7) mm (T1-T2:31.6％) in AP direction and (0.9±0.6) mm (T1-T2:37.5％) in vertical direction.At the time of 24 months after operation,the relapse distance was (1.0±0.5) mm (T1-T3:26.0％) in AP direction and (0.8±0.8) mm (T1-T3:33.3％) vertically.In non-cleft group,the maxilla was move (4.3±1.2) mm anteriorly and (2.2± 1.9) mm vertically.The relapse distance was (0.9±1.2) mm (T1-T2:20.9％) anteriorly and (0.8± 0.9) mm (T1-T2:36.6％) vertically at 6 months post-operatively.At 24 months after surgery the relapse distance was (1.1±0.6) mm (T1-T3:25.6％) anteriorly and (0.9±0.5) mm (T1-T3:40.9％) vertically.There were no statistical significant in both 6 months and 24 months follow-up between cleft and non-cleft group (P＞0.05).Conclusions There is no statistic difference of post-surgical relapse rate between cleft and non-cleft orthognathic and orthodontic treatments,although the relapse distances are greater than that in cleft group.

The comparison of 3D printing surgical guide and traditional occlusal splint in the treatment with facial asymmetry cases / 中华整形外科杂志

Objective@#To compare the surgical accuracy of the 3D printing surgical guide and traditional occlusal splint in the treatment of skeletal facial asymmetry cases.@*Methods@#12 facial asymmetric patients underwent joint orthognathic and orthodontics treatments were included in this research. In the 3D printing group (n=6) the pre-surgical CT scan for the skeleton and laser scan for the dentures were performed and 3D orthognathic procedures including Le FortⅠ and BSSRO combined with genioplasty were planned. The 3D printing surgical guides were manufactured and applied during surgeries. Another 6 cases were received same procedures by traditional occlusal splint techniques as the control group. Post-surgical CT reconstruction and 3D superimposition with pre-surgical planning was carried out for outcome comparison.@*Results@#The maximal error of maxillar was 0.65 mm and average error was less than 1 mm in 3D printing group, while the maxillary maximal error was 2.11 mm and average error was greater than 1 mm in traditional group which showed the statistical significance (P<0.05).@*Conclusions@#The usage of 3D printing surgical guide could improve the orthognathic surgical precision by controlling the jaw bone in a three-dimensional way.

Bioceramics in bone tissue engineering / 中国组织工程研究

BACKGROUND:Bioceramic has similar components compared to human bone tissue and it has shown good ostoconductivity both in vitro and in vivo.Meanwhile,it is biocompatible.So,bioceramics is considered as one of the most promising materials which can be applied to bone tissue engineering.OBJECTIVE:To summarize the properties of bioceramics and the research progress in experimental studies and clinical applications.METHODS:PubMed was searched for relevant articles published during 2000 to 2016 with the key words of bioceramics,hydroxylapatite,calcium phosphate,bioglass,bone tissue engineering in English.RESULTS AND CONCLUSION:Bioceramic materials can be divided into two categories:calcium phosphates and bioactive glass.Calcium phosphates have good biocompatibility and osteoconductivity,while the mechanical property is not so satisfying.Bioactive glass is biocompatible and beneficial to the expression of some osteogenic genes,but it is brittle and weak.Some kinds of bioceramics have already been applied to clinical practice.In recent years,calcium phosphates have also been used as coated materials to improve the properties of tissue-engineered scaffolds.Bioceramics combined with synthetic polymers,shows better mechanical performance and biodegradation.Even so,it still has plenty of problems and challenges as a widely used bone repair material in clinical practice.

3D bioprinting of tissues and organs and its application in oral medicine / 中国组织工程研究

BACKGROUND:3D bioprinting has been used to print a variety of tissues including skin,vascular tissues,liver,cartilage,cardiac tissues,ear,and adipose tissues.OBJECTIVE:To review the application of 3D bioprinting technology in printing tissues or organs and its research progress in oral medicine.METHODS:A computer-based retrieval of PubMed and CNKI was performed to search articles concerning the application of 3D bioprinting technology in printing tissues,organs and stomatology which were published from 2006 to 2016,using the keywords of 3D bioprinting,3D pinting,organs,tissues,tissue engineering,stomatology,oral,cranio-maxillofacial in English and Chinese,respectively.RESULTS AND CONCLUSION:Direct cell-bioprinting is still in its early stage,even though 3D bioprinting has been applied to print various tissues such as skin,vascular tissues,liver,cartilage and cardiac tissues,etc.Although additive manufacturing technology has been widely used for printing different scaffolds of tissues and organs nowadays,there are no successful bioprinted tissues with biological functions in clinical practice.Even in oral medicine,most of the studies still remain in the stage of printing biological scaffolds.It is a long way to solve the problems such as source of cells,materials of biological scaffolds and types of extracellular matrix in the future,due to the complexity of human organism structure and the function expression of various tissues and organs.

Strategies to Extend Thrombolytic Time Window for Ischemic Stroke Treatment: An Unmet Clinical Need / 대한뇌졸중학회지

To date, reperfusion with tissue plasminogen activator (tPA) remains the gold standard treatment for ischemic stroke. However, when tPA is given beyond 4.5 hours of stroke onset, deleterious effects of the drug ensue, especially, hemorrhagic transformation (HT), which causes the most significant morbidity and mortality in stroke patients. An important clinical problem at hand is to develop strategies that will enhance the therapeutic time window for tPA therapy and reduce the adverse effects (especially HT) of delayed tPA treatment. We reviewed the pharmacological agents which reduced the risk of HT associated with delayed (beyond 4.5 hours post-stroke) tPA treatment in preclinical studies, which we classified into those that putatively preserve the blood-brain barrier (e.g., minocycline, cilostazol, fasudil, candesartan, and bryostatin) and/or enhance vascularization and protect the cerebrovasculature (e.g., coumarin derivate IMM-H004 and granulocyte colony-stimulating factor). Recently, other new therapeutic modalities (e.g., oxygen transporters) have been reported which improved delayed tPA-associated outcomes by acting through other mechanisms. While the above-mentioned interventions unequivocally reduced delayed tPA-induced HT in stroke models, the long-term efficacy of these drugs are not yet established. Further optimization is required to expedite their future clinical application. The findings from this review indicate the need to explore the most ideal adjunctive interventions that will not only reduce delayed tPA–induced HT, but also preserve neurovascular functions. While waiting for the next breakthrough drug in acute stroke treatment, it is equally important to allocate considerable effort to find approaches to address the limitations of the only FDA-approved stroke therapy.

Application of MOOC teaching model in continuing medical education of oral and maxillofacial surgery / 中华医学教育探索杂志

Continuing medical education refers to the completion of basic medical education for inservice education,which is to guarantee the sustainable development of physicians in clinical and scientific research ability,and is the essential means to safeguard and improve the level of medical treatment.Traditional continuing medical education is given priority to the form of regularly organize workshops,so it has some limitations to oral and maxillofacial surgery.MOOC teaching is a kind of large-scale open new online teaching mode.This study provides an overview of the MOOC development,characteristics and development situation in the medical teaching.The necessity and feasibility of MOOC based teaching protocol in oral and maxillofacial surgery continuing medical education has been discussed.And curriculum transformation,construction of education model and possible challenges have also been analyzed and discussed in this paper.

The role and mechanism of parathyroid hormone in promoting bone formation / 中国组织工程研究

BACKGROUND:Osteoporosis is characterized by low bone mineral density and/or poor bone microarchitecture leading to an increased risk of fractures. Oral manifestations can be frequently discovered in osteoporosis patients. Osteoporosis therapies have mostly relied on antiresorptive drugs. Parathyroid hormone plays a significant role in osteogenesis and calcium deposition. Intermittent exposure to parathyroid hormone has been widely proved to lead to a net increase in bone formation. OBJECTIVE: To discuss the possibly celular and molecular mechanism of parathyroid hormone in strengthening the bone mineral density and regulating bone formation. METHODS: An online search of CNKI and Medline databases was performed for relevant articles using keywords of “parathyroid hormone; osteoporosis; osteoblast; osteogenesis” in Chinese and English, respectively. Relevant articles were summarized from three aspects: effects of parathyroid hormone on differentiation and proliferation of osteoblasts, effects of parathyroid hormone on osteoblast apoptosis, and the relationship of parathyroid hormone with Wnt/beta-catenin pathway and other cytokines. According to inclusion criteria, 41 articles were retained at last. RESULTS AND CONCLUSION:Parathyroid hormone exerts an effect on parathyroid hormone type I receptor, triggering a classic G protein signaling pathway. Parathyroid hormone mainly works through protein kinase A signaling pathway, adjusting its downstream c-reactive protein. Intermittent use of parathyroid hormone can increase osteoblast proliferation, increase osteoblast runx2 and osteocalcin at mRNA and protein levels, inhibit osteoblast apoptosis by against oxidative stress, so as to promote osteogenesis.

GSTM1 polymorphism,smoking,alcohol drinking and oral cancer susceptibility in Asians:A meta-analy-sis / 实用口腔医学杂志

Objective:To evaluate the association of glutathione S-transferase M1 (GSTM1 )polymorphism,smoking and alcohol drinking with oral cancer susceptibility in Asians by meta-analysis.Methods:A literature search of PubMed,Chinese BioMedical, Wanfang,VIP and CNKI databases from inception to July 30th,2013 was conducted.Crude odd ration (OR)with 95% confidence intervals (95%CI)was calculated.Results:27 case-control studies were assessed,and the results showed that the association be-tween GSTM1 null genotype and oral cancer susceptibility was significant in Asians (OR=1.31,95%CI:1.18-1.45,P<0.001), especially in South Asians (OR=1.35,95%CI:1.20 -1.52,P<0.001).Significant associations between oral cancer risk and smoking and alcohol drinking were found in East Asians (Smoking:OR=1.70,95%CI:1.36 -2.13,P<0.001;Alcohol drink-ing:OR=1.54,95%CI:1.24 -1.90,P<0.001).Conclusion:GSTM1 null genotype may be associated with increased oral cancer risk in Asians.Smoking and alcohol drinking confer significant susceptibility to oral cancer in East Asians.

Research advances in laser ablation of hard tissue / 国际生物医学工程杂志

Laser ablation of hard tissue allows very precise pre-programmed incisions with complete free geometry and it has advantage of leaving no tissue damages. Those disadvantages of thermal side effects and low cutting rates had been overcome by introducing ultra-short pulses and ultra-power laser systems. This review highlights the recent advances in the laser ablation of hard tissues.

Research progress in reanimation of peripheral facial paralysis by use of functional electrical stimulation / 生物医学工程学杂志

With the development of electronics and information technology, the application of functional electrical stimulation in the medical field has been expanding. However, the use of functional electrical stimulation to treat patients with peripheral facial paralysis is still in its infancy. The main problems include: (1) Finding in the signals which could fire the stimulator; (2) Exploring the parameters for the stimulator; (3) The effects on the muscle attributed to the electrical stimulation. A review on these problems is presented.

Computer-aided surgical simulation and navigation in reconstruction of old maxillofacial fractures / 上海交通大学学报（医学版）

Objective To apply the three-dimensional pre-operative simulation and intra-operative real-time navigation in the reconstruction of old maxillofacial fractures so as to increase the surgical precision. Methods Six patients with old maxillofacial fractures were enrolled, and the diagnosis of unilateral old maxillofacial fractures was confirmed by clinical and imaging examinations. Virtual three-dimensional skull models were reconstructed from pre-operative CT images. The fractured bone was moved or rotated, and was reposed in a desired site according to the mirrored part from the healthy side. After patient-to-image registration, the surgical instruments and patients were tracked in real-time by optical tracking system during operation, and in this way the maxillofacial fractures were reposed satisfactorily guided by the virtual image. Results Three-dimensional simulation before operation and real-time navigation of patients and instruments during operation were realized. The error of registration was less than 1 mm. The post-operative CT examinations of these six patients revealed that the fracture reposition was same to the pre-operative planning, and the difference between them was less than 1.5 mm. The operations were minimally-invasive, with no complications. Conclusion Computer-aided surgical simulation and navigation system can effectively increase the surgical precision of reconstruction of old maxillofacial fractures.

Regulation and control of bone marrow stromal cell differentiation towards chondrocytes / 中国组织工程研究

Adult chondrocytes had been used as seed cells in the previous tissue engineering; however, they possess the weaknesses including the limited proliferative capability in vitro and the liability to aging after amplification. Bone marrow stromal cells (BMSCs) are multipotent cells, which can differentiate into osteoblasts, chondrocytes, and adipocytes. It is of great importance to study the regulation and control of BMSC directed induction because directed differentiation is required in the tissue engineering. During the BMSC differentiation towards chondrocytes, serious kinds of biological inducing factors participate in precise induction as signal factors. The physical factors, such as biomechanical strength and ultrasound, have been shown to be involved in the regulation of BMSC differentiation towards chondrocytes. In terms of tissue repair, apart from biological factors which play an important role in the formation of cartilage tissue, the chondrocyte microenvironment in vivo is indispensable. Bioreactor is a kind of device intended for in vitro tissue culture that incubates the cells or tissues taken from living bodies in simulated physiological environment in vivo. On the basis of original cell culture, the present bioreactors apply biomechanical stimulation to simulate the stressed environment of articular cartilage in vivo.

Immunogenicity of osteoblasts prior to and after liquid nitrogen cryopreservation / 中国组织工程研究

BACKGROUND: Cryopreservation can decrease tissue and organ immunogenicity. The effects of cryopreservation on cell immunogenicity are disputed.OBJECTIVE: To investigate the effects of liquid nitrogen cryopreservation on osteoblast immunogenicity. DESIGN: Randomized,controlled ,paired-sample experiment. SETTING: This study was performed in the Laboratory Center, Qilu Hospital Affiliated to Shandong University between July 2003 and March 2004. MATERIALS: Four New Zealand rabbits of either gender were included for this study. 3H-TdR was provided by Nuclear Medicine Institute of Shandong University. METHODS: Osteoblasts were cultured from the tibial periosteum of New Zealand rabbits and then cryopreservated in the liquid nitrogen for 3 months and defrosted. Cryopreservated and thawn osteoblasts were set as cryopreserved group and freshly cultured osteoblasts were set as non-cyropreserved group. Major histocompatibility complex (MHC)-I positive rate was examined by flow cytometry assay prior to and after cryopreservation. Simultaneously, mixed lymphocyte-osteoblast cultures were established. Lymphocyte stimulation index was calculated after counting the flares using β liquid scintilloscope. MAIN OUTCOME MEASURES: MHI-I antigen positive rate and lymphocyte stimulation index prior to and after cryopreservation of osteoblasts. RESULTS: MHI-I antigen positive rate and lymphocyte stimulation index of osteoblasts was significantly higher in the non-cryopreserved group than in the cryopreserved group (P＜0.01). CONCLUSION: The immunogenicity of cryopreserved osteoblasts was significantly decreased. Liquid nitrogen cryopreservation is an ideal method to decrease the immunogenicity of osteoblasts.

UV spectral identification of Fritillaria walujewii / 中草药

Object To develop a method for the identification of Fritillaria walujewii Regel by UV spectrum. Methods UV spectrum of the absolute alcoholic extract of F. walujewii was determined and compared with that of four other similarly treated Fritillaria species. Results The UV spectrum of F. walujewii was consistently different with that of the other four species. Conclusion UV spectrum can be used to differentiate F. walujewii from other species of Fritillaria.