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 analyze the genetic characteristics of the prevalent strains of Varicella-Zoster virus (VZV) in the population of Dali, Yunnan, and to understand its evolutionary status in the population of Dali.Methods:Herpes fluid and 163 sera were collected from 249 patients clinically suspected to have varicella or herpes zoster in the Department of Dermatology of the Second People′s Hospital of Dali city, Yunnan province, China, from 2023 to 2024. The levels of VZV-specific IgG and IgM antibodies in serum were detected using enzyme-linked immunoassay. Viral DNA was extracted from the herpes fluid, and the cycle threshold ( Ct) of the samples was detected using quantitative real-time polymerase chain reaction (qPCR), and some samples with Ct ≦ 22 were selected for sequencing by next-generation sequencing technology (next-generation sequencing). Next-generation sequencing (NGS) was used to obtain 90 whole genome sequences of VZV, and the sequencing result were compared with the sequences of reference strains for multiple sequence comparison and evolutionary analysis. Snapgene was used to translate the nucleotides into amino acids, and the result were compared with the amino acid sequences of the reference strain. Results:Of the 90 VZV whole-genome sequences, one whole-genome sequence was from an adult varicella patient, and the remaining 89 whole-genome sequences were from herpes zoster patients. The serum-specific IgG antibody positivity rate was 99.4%, and the IgM antibody positivity rate was 52.8%. The result of both single nucleotide polymorphism (SNPs) site typing and genome-wide phylogenetic tree analysis showed that 83 of the 90 VZV whole-genome sequences in this study were on the same branch as Clade 2, and 7 VZV whole-genome sequences were on the branch of Clade 9.Conclusions:The main endemic branch in Dali region in 2023-2024 was Clade 2, with the emergence of Clade 9 branch; there were amino acid mutations in the proteins encoded by ORF22 and ORF68 in 83 VZV whole genome sequences of Clade 2 branch, and the mutations did not cause significant changes to the protein structure.

Objective:This study aims to provide insights into the clinical features of anti-melanoma differentiation-associated protein-5(MDA5)-positive dermatomyositis (MDA5-DM) patients with fatal outcomes, leveraging pathogenic microbiota metagenomic analysis, to guide the clinical assessment and treatment choices.Methods:From January 2020 to August 2023, deceased patients diagnosed with MDA5-DM were identified at the Department of Rheumatology and Immunology, the Second Affiliated Hospital of Xi ′an Jiaotong University. Clinical data were retrospectively collected and analyzed using Mann Whitney U test and Fisher ′s exact test to summarize risk factors and treatment assessment for MDA5-DM patients with fatal outcomes. Results:①The proportion of male patients was higher than females among MDA5-DM patients with fatal outcomes, which differed from the incidence pattern, possibly associated with smoking and gender proportions (6/11 vs. 0/7, P=0.037). ②94%(17/18) patients presented initially with elevated ferritin levels [(1 350±942)ng/ml] and CRP [(47±36)mg/L]. ③All patients (18/18) exhibited early involvement of the upper lung lobes, including multiple nodules in 9/18, ground-glass opacities in 5/18, and solitary nodules in 4/18. ④Metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid was negative in 4/16 cases, with cytomegalovirus and pneumocystis jirovecii being the most commonly detected pathogens in 5/16 cases each. ⑤89%(16/18) of patients continued to have lymphocyte counts persistently <0.5×10 9/L irrespective of treatment. Conclusion:Smoking may have adverse effects on male MDA5 patients. Early involvement of the upper lobe of the lungs is more common in MDA5 antibody positive deaths, and persistent lymphocyte depletion is an important factor in poor response. Enhancing mNGS analysis of bronchoalveolar lavage fluid and vigilance towards cytomegalovirusand Pneumocystis jirovecii could provide valuable clinical guidance.

Objective:To investigate the incidence, risk factors, and outcomes of falls among the elderly community population in Beijing.Methods:A cross-sectional survey was conducted using stratified multistage random sampling to select urban and rural residents aged 65 years and older in Beijing. Mortality data was collected after the baseline survey for 5 years. The incidence of falls was weighted based on the composition ratios of age and gender from the 2010 Nation-wide Population Census of Beijing. A logistic regression model was used to analyze the impacts of demographic sociology of common chronic diseases on fall occurrence. The Cox proportional hazards regression model was used to analyze the fall and 5-year survival association.Results:A total of 2 968 participants completed the questionnaire, at cross-sectional survey, with an average age of (73.2±6.0) years, and 1 581 (53.8%) participants were female. Three hundred and sixty-one individuals experienced a fall within the past year. Among those who fell, 64 (17.7%) fell twice, and 95 (26.6%) fell three or more times. Of them, 14.4% (52) had post-fall fractures, with the wrist, knee, and hip being the most common fracture sites, accounting for 25.0%, 17.3%, and 15.4%, respectively. The weighted fall incidence was 12.4% (95% CI: 11.2%-13.5%). Aging, being female, and living in rural areas were more likely to fall. Logistic regression analysis showed that after adjusting for age, gender, and urban-rural status, the risk of falls for those living alone ( OR=1.48, 95% CI: 1.08-2.04) or living with children/grandchildren ( OR=1.51, 95% CI: 1.15-1.97) were significantly higher than those living with their spouse. In addition, the risk of falls was elevated significantly among the elderly with hypertension, diabetes, stroke, dementia, depression status, urinary incontinence, arthritis, insomnia, vision, and hearing loss, dependence on activities of daily living (ADL), general and poor self-rated health (SRH). The Cox proportional hazard regression model revealed that the 5-year risk of death increased by 65% ( HR=1.65, 95% CI: 1.29-2.11) for those who experienced a fall, which increased with fall frequency. This elevated risk persisted after adjusting for chronic conditions, ADL, and SRH. Conclusions:Ageing, female, living in rural regions, having common chronic diseases, dependence on ADL, general and poor SRH, living alone or living with children/grandchildren were associated with the elevated fall risk. The occurrence of fall was seasonal. The most common short-term adverse consequence after a fall was fractures, while the long-term effect was an increased risk of death.

Objective:To evaluate the clinical efficacy of a novel reduction device in the treatment of A3N0/1 thoracolumbar fracture using navigation-assisted techniques.Methods:A retrospective analysis was conducted on 45 patients (29 males, 16 females; mean age 40.67±16.11 years, range 24-57) with thoracolumbar fractures who underwent fracture reduction and pedicle screw fixation via the Wiltse approach at Zhengzhou Orthopaedic Hospital between January 2022 and January 2023. Injury levels included: T 10 in 2 cases, T 11 in 5 cases, T 12 in 13 cases, L 1 in 20 cases, L 2 in 3 cases, L 3 in 2 cases. All patients underwent fracture reduction via the Wiltse approach using the spinal fracture reduction instrument for vertebral body reduction. Among them, 20 patients received O-arm navigation-assisted internal fixation and vertebral reduction (O-arm group), while 25 received C-arm fluoroscopy-guided internal fixation and vertebral reduction (C-arm group). Operative time, intraoperative blood loss, vertebral reduction time using the instrument, first-time screw placement success rate, screw placement accuracy, and complications were compared. Mid-vertebral body height ratio (MVBHr), local Cobb angle of the fractured vertebra, visual analogue scale (VAS) score, and Oswestry disability index (ODI) were compared preoperatively, at 1 week postoperatively, 3 months postoperatively, and final follow-up. Results:All surgeries were successfully completed in both groups. Operative time was significantly shorter in the O-arm group (106.8±14.4 min) than in the C-arm group (119.1±16.4 min, P<0.05). All patients were followed up for a mean duration of 15.9±3.9 months (range 12-20 months). Vertebral reduction time was significantly shorter in the O-arm group (11.0±2.2 min) than in the C-arm group (20.4±5.7 min, P<0.05). The first-time screw placement success rate was significantly higher in the O-arm group (100%) than in the C-arm group (95.3%, P<0.05). Screw placement accuracy (Grade I) was significantly higher in the O-arm group (117 screws, 97.5%) than in the C-arm group (136 screws, 90.7%, P<0.05). No cases of wrong-level surgery, infection, or spinal cord/nerve injury occurred. Both groups showed significant improvements in MVBHr, Cobb angle, VAS, and ODI at all postoperative time points compared to preoperative values ( P<0.05). At final follow-up, the O-arm group demonstrated significantly better outcomes than the C-arm group in MVBHr (90.6%±4.5% vs. 86.4%±6.9%, P<0.05), Cobb angle (7.6°±1.8° vs. 10.1°±3.2°, P<0.05), VAS (1.3±0.4 vs. 1.7±0.6, P<0.05), and ODI (4.6%±1.9% vs. 7.7%±2.0%, P<0.01). Conclusion:O-arm navigation-assisted intrasegmental push reduction for A3N0/1 type thoracolumbar fractures demonstrates advantages including faster and more accurate screw placement, precise reduction with improved outcomes, and significant postoperative pain relief.

Liver cancer is one of the leading causes of cancer-related mortality worldwide.The treatment paradigm of HCC is shifting from traditional"single-modality resection"toward an integrated model featuring"multi-strategy synergy".In recent years,neoadjuvant therapies,particularly those combining interventional approaches with immunotherapy before surgery had attracted much attention.The current evidences and emerging trends of interventional and immune-driven strategies in neoadjuvant therapy for liver cancer were reviewed in this article.

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.

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 evaluate the feasibility and outcomes of transnasal endoscopic clipping of the paraclival internal carotid artery (ICA) in skull base surgery.Methods:The paraclival ICA was anatomically dissected in cadaveric head specimens. The clinical data of 15 patients with skull base lesions involving the ICA who admitted to the Department of Otorhinolaryngology Head and Neck Surgery at Tianjin Huanhu Hospital from January 2021 to December 2023 were retrospectively analyzed. Among them, 4 patients underwent transnasal endoscopic clipping of the paraclival ICA and concurrent lesion resection. The surgical methods were summarized, and the key points and indications of this technique were analyzed.Results:Intraoperative clipping of the ICA was successful and hemostatic in all 4 patients. Postoperatively, 3 patients had no complications, while 1 patient developed delayed ischemic cerebral infarction. Two patients were cured, 1 patient was maintained on immunotherapy, and 1 patient died. During follow-up, the clip was in situ in 1 patient, had detached in another, and was obscured by temporal muscle coverage in the remaining 2 patients.Conclusions:Transnasal endoscopic clipping of the paraclival ICA represents a potential option for managing the ICA in skull base surgery. However, it carries significant risks and limitations, mandating careful patient selection based on specific circumstances.