Application of mixed reality in standardized resident training on oral and maxillofacial-head and neck tumor surgery / 中华医学教育探索杂志

Objective:To evaluate the effect of mixed reality (MR) in the standardized resident training on oral and maxillofacial-head and neck tumor surgery.Methods:Twenty resident doctors, who received standardized training in the department of maxillofacial oncology of our hospital, were randomly divided into experimental group and control group. The MR teaching method was used in the experimental group, while the traditional teaching method was used in the control group. The teaching effect was evaluated by theoretical and operational tests and a questionnaire survey. Statistical analysis was performed with the SPSS 24.0 software. Statistical comparisons were performed by the Students' t-test or the Wilcoxon rank correlation test. Results:The theoretical test results showed that the scores of the experimental group were significantly higher than those of the control group (85.30±3.59 vs. 80.20±5.63, t = 2.41, P = 0.027). The operational test results showed that the scores of the experimental group were significantly higher than those of the control group (89.20±5.07 vs. 82.30±6.36, t = 2.68, P = 0.015). The questionnaire survey results showed that the MR teaching helped to easily acquire the knowledge of head and neck anatomy and operation skills. Besides, the doctors in the experimental group were more active and glad to communicate with others than those in the control group. In addition, the MR teaching method improved the learning interest of doctors. The doctors in the experimental group were more satisfied with the teaching effect than those in the control group, and they recommended that the MR teaching method be used in clinical training and teaching on oral and maxillofacial-head and neck tumor surgery. Conclusion:MR teaching can help doctors understand and master the knowledge of head and neck anatomy and operation skills and improve their learning interest, achieving a good teaching effect, so it has important application value in the standardized resident training on oral and maxillofacial-head and neck tumor surgery.

Mechanical stretch promotes mesenchymal stem cell-osteoblast lineage migration through activation of mammalian target of rapamycin/matrix metalloproteinases signaling pathway / 中国组织工程研究

BACKGROUND:Distraction osteogenesis is one of the most important tissue engineering technologies. However, the exact signaling pathway controling mesenchymal stem cel-osteoblast lineage (MSC-OB) migration during distraction osteogenesis has not yet been elucidated. More efforts should be paid to make a ful understanding of the mechanism on MSC-OB lineage migration, which can improve the clinical efficacy of distraction osteogenesis. OBJECTIVE:To evaluate the effects of mechanical stretch on the ability of MSC-OB mobility and expression of mammalian target of rapamycin (mTOR) signaling pathway as wel as matrix metaloproteinases (MMPs) in MSC-OB, and to make clear the mechanism by which controls MSC-OB migration during distraction osteogenesis. METHODS:Twelve Sprague-Dawley rats were randomized into two groups: experimental group (n=6), anin vivo rat mandibular distraction osteogenesis model was established on the right side of rats; non-stretch group (n=6), only the mandibular resection was done but with no distraction osteogenesis. Immunohistochemical staining was used to detect phosphorylated mTOR expression in new osteotylus at 15 days after operation. In addition, an in vitro cel stretch model was made in the mandibular mesenchymal stem cels from healthy Sprague-Dawley rats under resting tension force (6%, 4 hours); no distraction was done in control group. The ability of MSC-OB mobility, the expression of mTOR, Raptor, p70S6K and MMPs were evaluated using experiment methods including immunohistochemistry staining, real-time PCR and scratch assay. RESULTS AND CONCLUSION: The expression of phosphorylated mTOR in MSC-OB was upregulated in the mandibular bone calus of the stretch group than the non-stretch group (P < 0.05). In thein vitro experiments, MSC-OB applied with mechanical stretch (6%, 4 hours) showed elevated gene expression levels of mTOR, Raptor, p70S6K, MMP-2, MMP-9 and MMP-13 compared with the control group (0%, 4 hours). Meanwhile, MSC-OB in the experiment group (6%, 4 hours) showed a greater ability of mobility, as demonstrated by a farther distance after 48 hours of observation (P < 0.05). The present study suggests that the enhancement of MSC-OB mobility correlates with increase of the gene expression of MMPs and mTOR signaling pathway. Mechanical stretch may promote MSC-OB migration through activation of mTOR/MMPs signaling pathway.

The expression and significance of Slug,EMMPRIN and E-cadherin in salivary adenoid cystic carcinoma / 实用口腔医学杂志

Objective:To investigate the expression of Slug,EMMPRIN and E-cadherin in salivary adenoid cystic carcinoma (SACC)and its correlation with clinicopathological characteristics,and the correlation among themselves.Methods:Slug,EMMPRIN and E-cadherin expression in 1 1 5 SACC cases of SACC was examined by immunohistochemical staining.The results and clinicopatho-logical data were statistically analyzed.Results:High positive expression frequencies of Slug(76.5%)and EMMPRIN(69.6%)and low positive expression frequency of E-cadherin(51 .3%)were found in 1 1 5 SACC cases.The expression of Slug and EMMPRIN was positively associated with the histopathological types,clinical stages,perineural invasion,recurrence and distance metastasis(P <0.05).The expression of E-cadherin was negatively associated with the histopathological types,clinical stages,perineural invasion and distance metastasis(P <0.05).There was a significant correlation between Slug and EMMPRIN expression(P <0.05),negative correlation between EMMPRIN and E-cadherin expression(P <0.05)and between Slug and E-cadherin expression(P <0.05).Con-clusion:The expression of Slug,EMMPRIN and E-cadherin is closely correlated to the clinicopathological characteristics of SACC.

Establishment of an animal model of blast-fragment combine injury on facial nerve / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study was to establish an animal model to imitate facial nerves injury by explosion.</p><p><b>METHODS</b>The impact was simulated by detonator blast in the distance of 5 cm, 10 cm and 15 cm over the face of dogs under anesthesia and the edge injury of masseters were made by rifle-shot steel ball to imitate segment injury in real explosion. The dogs were killed after different time of injury and the heart, lung, brain and facial nerve were taken to observe the pathological changes in order to evaluating the wound effect in different distances.</p><p><b>RESULTS</b>The animal was injured severely in the distance of 5 cm and could not survive for a long time because of severe damage to brain, heart and lung. The dogs injured at 10 cm could survive after emergency treatment, and there was diffusing hemorrhage in edematous nerve trunk. In the distance of 15 cm, the dogs were injured slightly and, as the distance to the explosive source increased, the local wound became slighter. Under light microscope, the breakage and necrosis of facial nerve fibers could be widely observed, degenerative and necrotic neurons with infiltrating inflammatory cells could be found in the facial nerve nuclei as well.</p><p><b>CONCLUSION</b>The dog's traumatic model established by impact wave and segment in this experiment is an appropriate animal model for the research of explosive effect on facial nerves because of its controllable and repeatable injuring conditions.</p>

Characteristics and management of 301 cases of civilian firearm injuries in maxillofacial region / 实用口腔医学杂志

Objective: To view the characteristics and the primary treatment of civilian firearm wound in the maxillofacial region.Methods: 301 cases of the casualties admitted to our hospital were retrospectively investigated,the epidemic, etiology, wound characteristics, and treatments of the patients were viewed respectively. Results: Of all the cases, the ratio of male to female was 5.1∶1.0. 57% of the injuries were caused by gunshot, 66% were with multiple injuries.16% combination wound were craniocerebral injuries. In this group of patients, more than 900 wound tracks were found, 72% of the tracks were nonpenetrating and 67% of those were with foreign bodies lodged in. Burns with blast injuries were the main complex wounds, which mostly occurred in explosion. The treatments mainly included life maintaining, earlier debridement and infection control. Conclusions: The maxillofacial firearm injuries are complex and have their own characteristics depending on the firearms, the wound styles and the regional anatomy. All the factors must be considered when treatment is given.

Inhibitary effects of hydroxycampothecin, pingyangmycin, cis-platinum or their combination on the human tongue carcinoma cells / 实用口腔医学杂志

objective: To study the effects of hydroxycampothecin(HCPT), pingyangmycin(PYM), cis platinum (DDP) or their combination on the proliferation of human tongue carcinoma Tca8113 cells. Methods: MTT assay, cell counting,clonogenic assay and HE staining were used to study the effects of HCPT, PYM, DDP or their combination on the proliferation of human tongue carcinoma Tca8113 cells. Results: ①Synergistic inhibiton was observed when HCPT at the concentration (ng/ml) of 10～100 combined with PYM at 32～320 or DDP at 32～320, antagonistic effect was observed when PYM at 32～320 combined with DDP at 32～320; ②After treatment with PYM, HCPT or PYM plus HCPT at IC 30 the clonogenecity (%) of the cells was 15.2, 11.6 and 4.1 respectively, while that of untreated cells 31.7. Conclusion: The combination of HCPT with PYM may be synergistic in the inhibition of tongue carcinoma cell proliferation.

Effects of hydroxycamptothecine and pingyangmycin alone or in combination on the proliferation and telomerase activity of human tongue carcinoma cells / 实用口腔医学杂志

Objective:To study the effects of hydroxycamptothecine(HC PT ) and pingyangmycin(PYM) alone or in combination(HCPT/PYM) on the proliferation and telomerase activity of human tongue carcinoma Tca 8113 cells.Methods :The growth inhibitary effects of HCPT or PYM on Tca 8113 cells were stu died by MTT assay and the IC 30 values of the two drugs were obtained. Then the cells were exposed to HCPT or PYM at IC 30 , or to their combination. T he clonogenecity, cell cycle distribution, morphological change and telomerase a ctivity were studied by clonogenic assay, flow cytometry,transmision electron mi croscopy and telomeric repeat amplification protocol (TRAP) respectively.Results:IC 30 (ng/ml) of HCPT and PYM was 109 and 416 respectivel y, when in combination(HCPT/PYM) the IC 30 of HCPT and PYM was 35 and 100 r espectively. The clonogenecity(%) of the control, HCPT,PYM and HCPT/PYM treated cells was 31.7,11.6,15.2 and 4.1 respectively. PYM decreased S and G 2 phase ce lls,increased G 1 phase cells.HCPT or HCPT/PYM decreased G 1 phase cells and i ncreased S and G 2 phase cells.Drug treatment resulted in cell organ degenerati on and decrese of telomerase activity.The A value at A 450 of telomerase in control,HCPT,PYM and HCPT/PYM treated cells was 1.89?0.03,0.82?0.02,0.77?0.0 2 and 0.53?0.02 respectively(P

A new animal model for the study of explosive injury in maxillofacial region / 实用口腔医学杂志

Objective: To establish an efficient animal model for the study of explosive injury in maxillofacial region.Methods: The detonator, steel spheres as fragments simulants shot by smooth-bore barrel and a synchronizer were used to define the wound model in the maxillofacial region of 18 dogs. The whole system was triggered when shooting. Wounding parameters and the changes of targets after explosion were observed and recorded. Results: The overpressure of blast wave decreased exponentially according to the distance from explosive. After injury, the local damage of dogs was serious and extensive compounded with the damages in heart, lung and brain. The injury was aggravated with the increasing of over pressure and energy absorption. Conclusion: The new wound model can be used for the study of explosive injury in maxillofacial region that is characterized by serious tissue damage and multi-etiology.

The effect of BMP-2 on the rabbit's facial nerve wound healing:Histological quantitive analysis and ultrastructural observation / 实用口腔医学杂志

Objective: To evaluate the effects of BMP 2 on wound healing of facial nerve. Methods: Facial nerve was crushed in 6 rabbits.1 ng of BMP 2 in 20 ?l of saline was injected around the injured nerve on one side, 20 ?l of saline was injected on the other side as the control.Each two animals were sacrificed 1d,2 and 4 weeks after injury.The nerve samples were studied by histological observation,electron microscopic observation and image pattern analysis.Results:Better healing was observed in BMP 2 treated nerves in 2 and 4 weeks.4 weeks after injury,the axon number on each 100 ?m2 in BMP 2 treated nerves and control ones was 0.946?0.572 and 0.614?0.430(P

Comparative study between the characteristics of facial nerve jnjury resulted from gun-shot and that from blast / 实用口腔医学杂志

Objective: To study the difference between the facial nerve injury by gun-shot and that by blast. Methods: 40 adult dogs were divided into 2 groups, with 20 dogs in each. In the blast group, the impact wave was simulated by detonator blast in the distance of 10 cm over the dog's masseter. At the same time,a steel ball was projected to the dog's face by a rifle to imitate segments in blast. In the gun-shot group, only the steel ball was used. Then the facial nerve was taken at the time of immediateness, 6 hours, 1 day, 3 days and 7 days following the injury for HE or immunocytochemical staining. And the facial nerve conduction velocity was examined 6 hours, 3 days and 7 days after injury.Results: The facial nerve edema was found in both groups just after injury. There was scattering hemorrhage and little hematoma below the spineurium in the gun-shot wound, as well as the diffusing bleeding and larger hematoma in blast wound. In the blast group, the severe edema could be found by light microscope in the whole extracranial facial nerve. Axonal fragments, infiltrating imflammatory cells and few neurofilament protein NF positive axons were observed. In the gun-shot group, only scattering damage was found within 2 cm from the wound track.Conclusion: The facial nerve injury by gun-shot bacomes less severe with the increase of distance from the wound track, but the blast injury is wider and more severe.

Tissue-engineered bone fabricated with scaffold of demineralized tubular bone matrix / 实用口腔医学杂志

Objective: To investigate the method of using tubular demineralized tubular bone matrix scaffold composited with marrow stromal osteoblasts to fabricate tissue-engineered bone in vivo. Methods: Marrow stromal cells were harvested from illiac bone of 5 New Zealand rabbits respectively. After being cultured and multiplied in vitro, marrow stromal cells were induced to differentiate to osteoblasts with dexamethasone. The induced cells were harvested and mixed with 1.5% alginate sodium solution to generate a cell suspension. The suspension was dropped into tubular demineralized bone (1～1.5 cm in length, 0.2～0.5 cm in diameter) and then gelled with 2.5% CaCl 2. The demineralized tubular bone matrix/osteoblasts composites were placed in the dorsum of the rabbit subcutaneously as autogenous cells transplantation. Samples were investigated 6 and 12 weeks after implantation with histological and roentgenographic examination. Results: Osteoid tissue and new bone were observed in 4 weeks. In 8 weeks, more new bone formation, cells lied in the lacunae and arranged in order were found.Conclusion: Demineralized tubular bone matrix can be used as scaffold for the marrow stromal osteoblasts and alginate which was employed as three dimension carrier for cell growing and producing extral cell matrix.

A preliminary study of injectable tissue-engineered bone / 实用口腔医学杂志

Objective: To develop injectable tissue-engineered bone. Methods: Bone marrow cells isolated from lilac bone of New Zealand rabbits were cultured and induced to differentiate Into osteoblasts. The osteoblasts were mixed with 20 g/L alginate sodium solution to generate osteoblasts/alginate composite with final cellular density of 5 ? 10 6/ml. Calcium chloride was used as cross-linking agent. The osteoblasts/alginate composite was injected into the dorsal subcutaneous tissue of nude mice. The injected material with surounding tissue were examined with X-ray and histopathologic technique. Results: Four and eight weeks after injection, the hard knobbles were easily palpated under the dorsal skin of the animals. On X-ray photograph the knobbles showed calcified tissue image. In histological analysis, new bone formation was observed in the osteoblasts/alginate composite. The osteogenesis was in association with regenerated hematopoietic bone marrow. Conclusion: New bone tissue can be created through the injection of alginate sodium mixed with marrow stromal osteoblasts.

Maxillofacial injuries in 470 children under 14 years of age / 实用口腔医学杂志

Objective:To investigate the causes, characteristics and treatment of maxillofacial trauma in children. Methods: A retrospective analysis of 470 consecutive maxillofacial records of the patients not older than 14 years was conducted. Data regarding age, gender, cause, anatomic site and treatment were reviewed. Results:Most of the patients were mals(335 cases, 71.3% ), with a male and female ratio of approximately 2. 5;1 of the injuries, 28. 5% were due to accidental falls, 17.0% traffic accidents and 10.0% sharp implementt cutting. Injuries of soft tissue often occurred on gingiva, cheek, lip and chin. Mandibuir fratures were the most common (55.1% ) of all bone fractures. Conservative therapy, such as closed reduction surgery, maxillomandibular fixation, was usually performed. Conclusion: ①Boys are more tendent to be victims of maxillofacial trauma than girls. ②Falls are the first cause of child victims. ③Gingiva, chin, lip, check and mandible are the most commonly injuried sites.

Experimental Study of Indirect Facial Nerve Injury Due to High Velocity Missile Wound / 中华创伤杂志

In the study, X—ray, patholoSy and electron neuro—physiology were used for obsering the injury of facial nerve. The result revealed that the microstructure of the facial nerve was damaged while the macrostructure unchansed. The microstructure changes included: fibre broken—up, bleeding in perineurium, deformation of axon, mitochondria swelling. Nerve evoking potential examination indicated that the latency was prolonsed, amplitude decreased and nerve conduction velocity was delayed. This results showed that there existed indired nerve injury. It is important to relieve the intraneural pressure, recover microcirculation and remove heamatoma in muscle and fascia in early stage

RESEARCH OF BONE REGENERATION WITH CULTURED OSTEOBLASTS SEEDED IN POROUS CORAL-HYDROXYLAPATITE / 解放军医学杂志

Rabbit osteoblasts were isolated, expanded in vitro, and then seeded into coral-hydroxylapatite. The osteoblasts/coral-hydroxylapatite composite was were implanted into the muscles of rabbits′ back. Bone regeneration was observed 4, 8 weeks after implantation by histological and scanning electron microscopic examinations.The results showed that osteoblasts could adhere and proliferate well on the surface of coral-hydroxylapatite. 4 weeks after implantation osteoid tissue was observed, 8 weeks after implantation large amount of new bone was found. It suggested that osteoblasts/coral-hydroxylapatite composite may be used for bone tissue engineering.