Malocclusion,identified by the World Health Organization(WHO)as one of three major oral diseases,profoundly impacts the dental-maxillofacial functions,facial esthetics,and long-term development of～260 million children in China.Beyond its physical manifestations,malocclusion also significantly influences the psycho-social well-being of these children.Timely intervention in malocclusion can foster an environment conducive to dental-maxillofacial development and substantially decrease the incidence of malocclusion or reduce the severity and complexity of malocclusion in the permanent dentition,by mitigating the negative impact of abnormal environmental influences on the growth.Early orthodontic treatment encompasses accurate identification and treatment of dental and maxillofacial morphological and functional abnormalities during various stages of dental-maxillofacial development,ranging from fetal stages to the early permanent dentition phase.From an economic and societal standpoint,the urgency for effective early orthodontic treatments for malocclusions in childhood cannot be overstated,underlining its profound practical and social importance.This consensus paper discusses the characteristics and the detrimental effects of malocclusion in children,emphasizing critical need for early treatment.It elaborates on corresponding core principles and fundamental approaches in early orthodontics,proposing comprehensive guidance for preventive and interceptive orthodontic treatment,serving as a reference for clinicians engaged in early orthodontic treatment.

Objective To investigate the effect of salidroside(SAL)on the proliferation and migration of human vascular endothelial cell line EA.hy926.Methods The cells were divided into control group and test groups of 1,10 and 100 nmol/L SAL,10 nmol/L SAL+2 μg/mL avastin(vascular endothelial growth factor(VEGF)blocker)group,10 nmol/L SAL+2 μg/mL IgG(blocker negative control)group,10 nmol/L SAL+8 μg/mL avastin group,10 nmol/L SAL+8 μg/mL IgG group,10 μmol/L YC-1[hypoxia inducible factor-1α(HIF-1α)blocker]group and 10 μmol/L YC-1+10 nmol/L SAL group.The proliferation and migration of EA.hy926 cells were detected by MTS assay and Transwell cell migration experiments.RT-qPCR and Western blot were used to measure the gene and protein level of HIF-1α and VEGF.The luciferase report gene experiment was used to find the effect of SAL on HIF-1α transcription activity of EA.hy926 cells.The guanylate cyclase activator(YC-1)was used as a HIF-1α blocker to verify potential effect of SAL on the expression of VEGF through HIF-1α.Results SAL significantly promoted proliferation of EA.hy926 cells(P＜0.05)and the proliferation promoting effect of SAL(10 nmol/L)was significantly reduced by the VEGF blocker bevacizumab avastin(2 μg/mL)(P＜0.05).SAL significantly promoted migration of EA.hy926 cells(P＜0.05),and this effect was significantly inhibited by avastin(8 μg/mL)(P＜0.05).SAL increased the expression of HIF-1α and VEGF gene and protein,and promoted the transcription of HIF-1α(P＜0.05).The level of HIF-1α and VEGF protein decreased by YC-1,a HIF-1α bloc-ker(P＜0.05).Conclusions HIF-1α/VEGF pathway is potentially involved in SAL promoted proliferation and migration of EA.hy926 cells.

Background and objective Small cell lung cancer(SCLC)is known as recalcitrant cancer with high malignancy and heterogeneity.Immunotherapy has changed the treatment pattern of extensive-disease SCLC(ED-SCLC),but the beneficiary population is limited.Therefore,exploring new therapeutic strategies is an urgent clinical problem to be solved for SCLC.SCLC is characterized by highly active glycolytic metabolism and pyruvate kinase Ml(PKM1)is one of the isozymes of PK,an important rate-limiting enzyme in glycolysis pathway.Previous studies have shown that PKM1 is related to autophagy and drug sensitivity,however,how PKM1 regulates drug sensitivity in SCLC and its mechanism remain unclear.The aim of this study was to investigate the biological functions of PKM1 in SCLC,including its effects on proliferation,migra-tion,autophagy,drug sensitivity,and expression of neuroendocrine(NE)-related markers in SCLC.Methods Western blot was used to detect the expression level of PKM1 in SCLC cells.PKM1 gene-overexpressed SCLC cell lines were constructed by stable lentivirus transfection.Proliferation of cells and drug sensitivity were detected by MTT,and migration ability of cells was determined by Transwell.The level of autophagy was detected by flow cytometry.Western blot was used to determine the expression levels of NE-related proteins.Results PKM1 was differentially expressed among various SCLC cell lines,and was lower in H1092 cells(P＜0.01).Compared with the control group,there was no significant difference in proliferation level of PKM1 overexpressing H1092 cell,but the migration ability was significantly increased(P＜0.001),the drug sensitivity was re-duced,and the level of autophagy was inhibited(P＜0.001).Additionally,overexpression of PKM1 could upregulate the expres-sion of non-neuroendocrine(non-NE)-related proteins(P＜0.01)and decrease the expression of NE-related proteins(P＜0.01).Conclusion PKM1 was differentially expressed in SCLC cell lines,and high expression of PKM1 did not affect the prolifera-tion,but affected the migration of SCLC cells.PKM1 might affect drug sensitivity by inhibiting autophagy and regulating the expression of NE markers.These results provide a theoretical basis for exploring the role of PKM1 in SCLC.

Chronic refractory wound (CRW) is one of the most challengeable issues in clinic due to complex pathogenesis, long course of disease and poor prognosis. Experts need to conduct systematic summary for the diagnosis and treatment of CRW due to complex pathogenesis and poor prognosis, and standard guidelines for the diagnosis and treatment of CRW should be created. The Guideline forthe diagnosis and treatment of chronic refractory wounds in orthopedic trauma patients ( version 2023) was created by the expert group organized by the Chinese Association of Orthopedic Surgeons, Chinese Orthopedic Association, Chinese Society of Traumatology, and Trauma Orthopedics and Multiple Traumatology Group of Emergency Resuscitation Committee of Chinese Medical Doctor Association after the clinical problems were chosen based on demand-driven principles and principles of evidence-based medicine. The guideline systematically elaborated CRW from aspects of the epidemiology, diagnosis, treatment, postoperative management, complication prevention and comorbidity management, and rehabilitation and health education, and 9 recommendations were finally proposed to provide a reliable clinical reference for the diagnosis and treatment of CRW.

Objective:To explore the clinical application of a new high dielectric constant (HDC) to improve image quality in 3.0 T fetal head MR scans.Methods:Forty pregnant women who underwent 3.0 T fetal head MR examinations at the Drum Tower Hospital of Nanjing University School of Medicine from May to July 2021 were prospectively included and divided into a test group and a control group according to the placement and non-placement of HDC pads. After the scans were completed, qualitative and quantitative analysis were performed on the image quality of the two groups acquired in each case. Qualitative analysis: A 5-point scale was used to score the images of both groups by two diagnosticians and their scores were recorded. Quantitative analysis: Firstly, the overall radiofrequency specific absorption ratio (SAR) values of the two sets of fetal cranial cross-sectional scans of each pregnant woman were recorded separately, and the average rate of change of the overall SAR values was calculated; secondly, four regions of interest (ROIs) were placed on the standard level of the cross-sectional section of each fetal cranium (including the level of the basal ganglia region of the dorsal thalamus), and the minimum and maximum of the four ROIs of each of the two data sets were calculated separately. The ratio of minimum to maximum signal intensity (RSI), signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated for each of the four ROIs in the two sets of data. Wilcoxon test was used to analyze the differences between the two groups of image quality score results; paired sample t-test or paired rank sum test was used to analyze the differences in SAR, RSI, SNR and CNR values between the two groups. Results:The fetal head image quality score was 4 (3, 4) in the test group and 3 (1, 4) in the control group, and the test group was significantly higher than the control group, with statistically significant difference ( Z=-3.62, P<0.01), and the images in the test group had a uniform signal compared with the control group, and none of them had significant artifacts. The results of quantitative analysis showed that the overall SAR value of the test group was significantly reduced, with a mean reduction rate of 32.1%, and the difference between the SAR values of the two groups was statistically significant ( Z=-2.78, P<0.01). The RSI, SNR and CNR in the frontal, temporal, thalamic and occipital lobes of the test group were all higher than those of the control group, and the differences were all statistically significant ( P<0.01). Conclusion:The HDC pads can significantly improve the image quality of 3.0 T fetal head imaging by reducing or eliminating the inhomogeneous artifacts in the RF field, which makes a good technical foundation for fetal head MR imaging.

Objective:To analyze the incidence and epidemiological characteristics of traumatic spinal cord injury in China in 2018.Methods:Multi-stage stratified cluster sampling was used to randomly select hospitals capable of treating patients with spinal cord injury from 3 regions，9 provinces and 27 cities in China to retrospectively investigate eligible patients with traumatic spinal cord injury admitted in 2018. National and regional incidence rates were calculated. The data of cause of injury，injury level，severity of injury，segment and type of fracture，complications，death and other data were collected by medical record questionnaire，and analyzed according to geographical region，age and gender.Results:Medical records of 4，134 patients were included in this study，with a male-to-female ratio of 2.99∶1. The incidence of traumatic spinal cord injury in China in 2018 was 50.484 / 1 million （95% CI 50.122-50.846）. The highest incidence in the Eastern region was 53.791 / 1 million （95% CI 53.217-54.365）. In the whole country，the main causes of injury were high falls （29.58%），as well as in the Western region （40.68%），while the main causes of injury in the Eastern and Central regions were traffic injuries （31.22%，30.10%）. The main injury level was cervical spinal cord in the whole country （64.49%），and the proportion of cervical spinal cord injury in the Central region was the highest （74.68%），and the proportion of lumbosacral spinal cord injury in the Western region was the highest （32.30%）. The highest proportion of degree of injury was incomplete quadriplegia （55.20%），and the distribution pattern was the same in each region. A total of 65.87% of the patients were complicated with fracture or dislocation，77.95% in the Western region and only 54.77% in the Central region. In the whole country，the head was the main combined injury （37.87%），as well as in the Eastern and Central regions，while the proportion of chest combined injury in the Western region was the highest （38.57%）. A total of 32.90% of the patients were complicated with respiratory complications. There were 23 patients （0.56%） died in hospital，of which 17（73.91%） died of respiratory dysfunction. Conclusions:The Eastern region of China has a high incidence of traumatic spinal cord injury. Other epidemiological features include high fall as the main cause of injury cervical spinal cord injury as the main injury level，incomplete quadriplegia as the main degree of injury，head as the main combined injury，and respiratory complications as the main complication.

Since December 2019, novel coronavirus pneumonia (NCP) has been reported in Wuhan, Hubei Province, and spreads rapidly to all through Hubei Province and even to the whole country. The virus is 2019 novel coronavirus (2019-nCoV), never been seen previously in human, but all the population is generally susceptible. The virus spreads through many ways and is highly infectious, which brings great difficulties to the prevention and control of NCP. Based on the needs of orthopedic trauma patients for emergency surgery and review of the latest NCP diagnosis and treatment strategy and the latest principles and principles of evidence-based medicine in traumatic orthopedics, the authors put forward this expert consensus to systematically standardize the clinical pathway and protective measures of emergency surgery for orthopedic trauma patients during prevention and control of NCP and provide reference for the emergency surgical treatment of orthopedic trauma patients in hospitals at all levels.

Objective To assess the efficacy of using reaming and antibiotic cement beads/rod for intramedullary nail associated infection.Methods Data of 12 patients with intramedullary infection of tibia or femur following intramedullary nailing from October 2014 to April 2016 were retrospectively analyzed.There were 10 men and 2 women aged from 19 to 63 years old with an average age of 39.2 years.In 5 cases the disease was localized in the femur with one case of nonunion,and in other 7 cases the disease was localizedin the tibia with two cases of nonunion.The initial injury included closed fracture in 8 patients and open fracture in 4 patients which were all Gustilo-Anderson Ⅱ.According to the Cierny-Mader classification of adult osteomyelitis,6 cases were type Ⅰ (medullary osteomyelitis),4 cases were type Ⅰ combined with type Ⅲ (medullary.and localized osteomyelitis),and 2 cases were type Ⅰ combined with type Ⅳ (medullary and diffuse osteomyelitis).Surgical technique included removal of the intramedullary nailand reaming and irrigation of the medullary canal to remove intramedullary debris.The drainage sinus and soft tissues abscess were excised if existed.An local or enbloc resection for the infected or necrotic bone was performed if there was local or diffuse infection in the fracture sites.Ilizarov technique was performed for segment bone defect.The bone union was observed in nine patients and stable nonunion in one.Antibiotic PMMA beads were inserted into intramedullary canal for these ten cases after debridement,and the antibiotic beads were removed approximately 12-14 days after implantation.The antibiotic cement rod was inserted into the medullary canal to provide stabilization in the other 2 cases.All the patients received intravenous antibiotics systemically for three weeks,and followed by three weeks of oral antibiotics.Results At a mean follow-up period of 23.5 months (range,15-33 months),no recurrence of infection was observed.There were 3 cases of nonunions.One case of tibial nonunion had been achieved union 10 months after insertion of an antibiotic cement rod.One with stable nonunion of tibia was treated with antibiotic PMMA beads,and enbloc resection for the infected bone was performed after the extension of infection had been narrowed at the nonunion.6 cm of bone defect was treated with bone transport and then union was obtained 16 months after operation.The third case was infected nonunion in the femur with 4 cm bone defect after debridement.The femur was shortened and temporarily stabilized with the intramedullary antibiotic cement rod.The rod was removed three months after the operation,and then the femur was lengthened.The docking site and the regeneration area were healed 12 months after the lengthening operation.Conclusion The clinical results shows that reaming and antibiotic cement beads/rod appears an effective and safe alternative for management of intramedullary nail associated infection of the tibia and femur.

Objective To evaluate the effects of betulinic acid preconditioning on oxidative stress response during cerebral ischemia-reperfusion (I/R) in mice.Methods Seventy-two male Kunming mice,aged 3 months,weighing 25-35 g,were randomly divided into 3 groups (n =24 each) using a random number table:sham operation group (group S),I/R group,and betulinic acid preconditioning group (group BP).Cerebral I/R was induced by middle cerebral artery occlusion in mice anesthetized with 10％ chloral hydrate 40 ml/kg.In group BP,betulinic acid 50 mg/kg was administered by intragastric gavage everyday for 7 days before ischemia,while the equal volume of solvent dimethyl sulfoxide was given in S and I/R groups.At 22 h of reperfusion,neurological function was assessed and scored.The mice were then sacrificed and brains were removed for determination of infarct size,expression of NADPH oxidase (Nox1,Nox2 and Nox4) and p22phox mRNA,activity of ROS and apoptosis rate in the infarcted zone.Results Compared with S group,neurological score,cerebral infarct size,activity of ROS and apoptosis rate in the infarcted zone were significantly increased,and the expression of Nox1,Nox2,Nox4 and p22phox mRNA was up-regulated in group I/R.Compared with group I/R,neurological score,cerebral infarct size,activity of ROS and apoptosis rate in the infarcted zone were significantly decreased,and the expression of Nox1,Nox2,Nox4 and p22phox mRNA was down-regulated in group BP.Conclusion Betulinic acid preconditioning mitigates cerebral I/R injury through inhibiting oxidative stress response in mice.