BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

Objective To introduce the method and results of modeling validation of the treatment planning system used in the first Mevion proton therapy system in China.Methods The SOBP(Spread-Out Bragg Peak)beams in water were designed according to the TG-185 report.The treatment plans in water were designed according to the TG-350 report.The treatment plans of patients were designed on the CT images.The plane dose of each beam was measured by using the MatriXX ONE ioni-zation chambers at different depths in the water,and the measurment results were compared with the TPS calculated results to verify the accuracy of the output doses,the error requirements were 2％/2 mm.Results Except for the distal fall-off position,the doses deviation at the SOBP beams center were less than 3％,and the γ analysis pass rates of plane doses were more than 90％.The measured results of the treatment plan beams were within the tolerance of deviation,and the output doses of the beams without or with static adaptive aperture were more accurate in general.With the decrease of beam energy,the error of dose calculation will increase.Conclusion According to the accuracy requirements of the planning system calculation and treat-ment system implementation,the proton therapy system supporting the treatment planning system has been modeled.Some basic performance such as IDD and beam spot is consistent with the actual measurement,and the TPS modeling conforms to the actual performance of the machine executing when calculating the same proton radiotherapy plan.

Objective To analyze the expression levels of miR-27a-3p mRNA and Yes-associated protein 1(YAP1)mRNA in breast cancer,and to explore their relationships with clinicopathological features and the survival prognosis of patients.Methods A total of 130 breast cancer patients who underwent mastectomy in our hospital between January 2019 and January 2021 were enrolled.The expression levels of miR-27a-3p and YAP1 mRNA in breast tumor tissues and adjacent normal breast tissues were assessed by qRT-PCR.Furthermore,the relationships between their expression and clinicopathological features,as well as the survival prognosis of patients,were investigated.Results Compared with adjacent normal breast tissues,the expression of miR-27a-3p mRNA in breast tumor tissues was lower(P＜0.05),while that of YAP1 mRNA was higher(P＜0.05).A negative correlation was observed between the expression of miR-27a-3p mRNA and YAP1 mRNA in breast tumor tissues(r=-0.456,P＜0.05).The expression of miR-27a-3p mRNA was correlated with tumor diameter,histological grade,tumor staging by the TNM system,lymph node metastasis,and vascular invasion in patients with breast cancer(P＜0.05).The YAP1 mRNA expression was correlated with histological grade,tumor staging by the TNM system,lymph node metastasis,and vascular invasion(P＜0.05).Kaplan-Meier survival analysis revealed that the 3-year overall survival rate of the miR-27a-3p low-expression group was 71.60％(48/67),which was lower than the 91.50％(54/59)of the miR-27a-3p high-expression group(log-rank x2=8.211,P=0.004).The 3-year overall survival rate of the YAP1 high-expression group was 73.80％(45/61),lower than that of the YAP1 low-expression group(87.70％,57/65)(log-rank x2=4.429,P=0.035).Multivariate regression analysis indicated that lymph node metastasis(hazard ratio[HR]=1.409;95％CI,1.057-1.644;P=0.046),vascular invasion(HR=1.541;95％CI,1.076-1.869;P=0.045),low miR-27a-3p mRNA expression(HR=0.593;95％CI,0.388-0.925;P=0.018),and high YAP1 mRNA expression(HR=0.628;95％CI,0.405-0.912;P=0.022)were relevant factors affecting the 3-year overall survival of patients with breast cancer.Conclusion A significant downregulation of miR-27a-3p mRNA and upregulation of YAP1 mRNA are observed in breast tumor tissues.The low expression of miR-27a-3p mRNA and the high expression of YAP1 mRNA are associated with adverse clinicopathological features and poor survival prognosis,and are risk factors affecting the 3-year overall survival of patients with breast cancer.They show promise as new potential therapeutic targets for breast cancer.

Objective To evaluate the influencing factors of aspiration in neurological critically ill patients by Meta-analysis.Methods PubMed,Embase,Web of Science,CNKI,and Wanfang Data were searched from inception to 1 October,2023,to obtain relevant studies on influencing fac-tors of aspiration in neurological critically ill patients.The literature screening,data extraction and quality evaluation were completed by two researchers.RevMan 5.4 and Stata 13.0 software were ap-plied for pooled Meta-analysisand assessed publication bias,respectively.Results A total of 8 arti-cles,including 1,315 neurocritical care patients,were included in this study.Nine influencing factors related to aspiration were extracted for Meta-analysis.The Meta-analysis results showed that the three influencing factors that caused aspiration in neurocritical care patients were stroke history(OR=5.03,95％CI,2.71 to 9.32,P＜0.000 01),National Institutes of Health Stroke Scale(NIHSS)score＞10(OR=3.35,95％CI,1.75 to 6.42,P=0.000 3),and gastric residual volume＞150mL(OR=7.13,95％CI,2.55 to 9.96,P=0.001).Conclusion This study provides a scientific basis for clinical healthcare professionals to early identify high-risk patients for aspiration,take targeted inter-vention measures,and prevent the occurrence of aspiration.

Objective To introduce the method and results of modeling validation of the treatment planning system used in the first Mevion proton therapy system in China.Methods The SOBP(Spread-Out Bragg Peak)beams in water were designed according to the TG-185 report.The treatment plans in water were designed according to the TG-350 report.The treatment plans of patients were designed on the CT images.The plane dose of each beam was measured by using the MatriXX ONE ioni-zation chambers at different depths in the water,and the measurment results were compared with the TPS calculated results to verify the accuracy of the output doses,the error requirements were 2％/2 mm.Results Except for the distal fall-off position,the doses deviation at the SOBP beams center were less than 3％,and the γ analysis pass rates of plane doses were more than 90％.The measured results of the treatment plan beams were within the tolerance of deviation,and the output doses of the beams without or with static adaptive aperture were more accurate in general.With the decrease of beam energy,the error of dose calculation will increase.Conclusion According to the accuracy requirements of the planning system calculation and treat-ment system implementation,the proton therapy system supporting the treatment planning system has been modeled.Some basic performance such as IDD and beam spot is consistent with the actual measurement,and the TPS modeling conforms to the actual performance of the machine executing when calculating the same proton radiotherapy plan.

OBJECTIVE To investigate the management status of small pressure steam sterilizers in dental institu-tions across seven major regions of China and provide references for establishing standardized monitoring and eval-uation protocols for sterilization efficacy.METHODS From Aug.to Nov.2023,a convenience sampling method was employed to select 885 dental institutions of various levels from seven geographical regions.An online survey using a self-designed questionnaire was conducted to assess the management status of small pressure steam steri-lizers in dental institutions.RESULTS A total of 885 questionnaires were distributed,with 770 valid responses col-lected,covering 770 dental institutions at all levels.The survey involved 2 056 small pressure steam sterilizers,of which 43.14％were pre-vacuum type and 89.40％were benchtop models.Tertiary dental institutions had the high-est proportion of imported small pressure steam sterilizers(60.15％),with most devices in use for 5-10 years(36.88％).Secondary and low er-level institutions predominantly used domestically produced small pressure steam sterilizers(74.60％),which used for 3-5 years accounting for the highest proportion(34.29％).While 85.58％of dental institutions employed dedicated sterilization personnel,only 45.84％performed proper maintenance for small pressure steam sterilizers.Training rates were 80.00％for department of stomatology in ungraded general hospitals and primary medical institutions,76.19％in prejob and 71.43％during the work for department of sto-matology in primary clinics,respectively.CONCLUSIONS Although most dental institutions demonstrate sound policy formulation,challenges persist in equipment maintenance,policy implementation and grassroots training.Future efforts should be made on strengthening maintenance and inspection of equipment,enhancing sys-tem supervisory mechanisms,and optimizing training systems to ensure dental treatment safety.

OBJECTIVE To investigate the management status of small pressure steam sterilizers in dental institu-tions across seven major regions of China and provide references for establishing standardized monitoring and eval-uation protocols for sterilization efficacy.METHODS From Aug.to Nov.2023,a convenience sampling method was employed to select 885 dental institutions of various levels from seven geographical regions.An online survey using a self-designed questionnaire was conducted to assess the management status of small pressure steam steri-lizers in dental institutions.RESULTS A total of 885 questionnaires were distributed,with 770 valid responses col-lected,covering 770 dental institutions at all levels.The survey involved 2 056 small pressure steam sterilizers,of which 43.14％were pre-vacuum type and 89.40％were benchtop models.Tertiary dental institutions had the high-est proportion of imported small pressure steam sterilizers(60.15％),with most devices in use for 5-10 years(36.88％).Secondary and low er-level institutions predominantly used domestically produced small pressure steam sterilizers(74.60％),which used for 3-5 years accounting for the highest proportion(34.29％).While 85.58％of dental institutions employed dedicated sterilization personnel,only 45.84％performed proper maintenance for small pressure steam sterilizers.Training rates were 80.00％for department of stomatology in ungraded general hospitals and primary medical institutions,76.19％in prejob and 71.43％during the work for department of sto-matology in primary clinics,respectively.CONCLUSIONS Although most dental institutions demonstrate sound policy formulation,challenges persist in equipment maintenance,policy implementation and grassroots training.Future efforts should be made on strengthening maintenance and inspection of equipment,enhancing sys-tem supervisory mechanisms,and optimizing training systems to ensure dental treatment safety.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

Cervical spinal cord injury without fracture-dislocation (CSCIWFD) is referred to as a special type of cervical spinal cord injury characterized by traumatic spinal cord dysfunction and no significant bony structural abnormalities on imagines. Duo to the high risk of missed diagnosis during the initial consultation, CSCIWFD may lead to progressive neurological deterioration or even complete paralysis, severely impacting patients′ prognosis. Currently, there are no established consensuses over the diagnosis and treatment of CSCIWFD, such as the lack of evidence-based standards for indications of non-surgical treatment and risk of secondary neurological injury, as well as debates over the optimal timing for surgical intervention and indications for different surgical approaches. To address these issues, the Spine Trauma Group of the Orthopedic Branch of the Chinese Medical Doctor Association organized experts in the relevant fields to formulate Diagnosis and treatment guideline for acute cervical spinal cord injury without fracture- dislocation in adults ( version 2025) . Based on evidence-based medicine and the principles of scientific rigor and clinical applicability, the guidelines proposed 11 recommendations covering terminology, diagnosis, evaluation treatment, and rehabilitation, etc., aiming to standardize the management of CSCIWFD.