1.Neuroprotective Effects of Transcranial Magneto-acoustic Stimulation on Parkinson’s Disease Model Mice by Regulating Mitophagy and Mitochondrial Homeostasis
Shuai ZHANG ; Yan-Bin WANG ; Yi-Hao XU ; Jin-Rui MI ; Xiao-Chao LU ; Yu-Chen AN ; Ji-Zhou LIU ; Jia-Qi SUN
Progress in Biochemistry and Biophysics 2026;53(5):1457-1470
ObjectiveTranscranial magneto-acoustic stimulation (TMAS) is an emerging non-invasive neuromodulation technique that may provide a novel non-pharmacological intervention strategy for Parkinson's disease (PD). PD is characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc), leading to motor impairments such as bradykinesia, tremor, and rigidity. Increasing evidence indicates that mitochondrial dysfunction and impaired mitochondrial quality control are central mechanisms underlying dopaminergic neuronal loss. In particular, abnormalities in mitophagy and mitochondrial fission-fusion balance contribute substantially to oxidative stress, energy metabolic failure, and neuronal injury. At present, most clinical treatments for PD mainly alleviate symptoms but do not effectively halt disease progression. Therefore, exploring new interventions targeting the core pathological mechanisms is of considerable significance. This study aims to investigate whether TMAS can improve neural damage and motor dysfunction in PD mice by regulating mitophagy and the fission/fusion dynamic balance, thereby providing theoretical and experimental support for its application in PD treatment. MethodsMale C57BL/6 mice were used in this study. A PD model was established by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 7 consecutive days. After model induction, mice in the intervention group received TMAS once daily for 14 consecutive days, whereas the corresponding control group received sham stimulation. The stimulation target was positioned over the primary motor cortex (M1). Motor performance was evaluated using the pole test and the open-field test. To verify the activation effect of TMAS on the target cortical region, c-Fos immunohistochemistry was performed in the M1. To assess nigral dopaminergic neuronal injury, tyrosine hydroxylase (TH) immunohistochemistry was used to quantify TH-positive neurons in the SNc. Mitochondrial function was evaluated by measuring reactive oxygen species (ROS) levels and adenosine triphosphate (ATP) content in the SNc. Western blot was further performed to determine the expression of mitophagy-related proteins, including PINK1, Parkin, LC3-II, and p62, as well as mitochondrial dynamics-related proteins, including Drp1 and Opa1. ResultsTMAS significantly increased the number of c-Fos-positive cells in M1 (P<0.000 1), indicating effective activation of neurons in the targeted cortical region. Compared with the control group, MPTP-treated mice exhibited marked motor dysfunction, including a significant reduction in total distance traveled in the open-field test (P<0.000 1) and mean speed (P=0.000 1), as well as significant prolongation of turn time and total climbing time in the pole test (P<0.000 1). These behavioral impairments were accompanied by a substantial loss of TH-positive dopaminergic neurons in the SNc, whereas TMAS significantly increased TH-positive neuron survival (P<0.000 1). In parallel, MPTP induced a pronounced increase in ROS levels and a significant reduction in ATP content, indicating severe mitochondrial dysfunction and energy metabolism impairment (P<0.01). TMAS treatment significantly improved motor performance, as reflected by the reversal of MPTP-induced impairment in the open-field and pole tests, and significantly reduced ROS accumulation (P<0.01) while restoring ATP production (P<0.001). At the molecular level, MPTP markedly downregulated PINK1 and Parkin, decreased p62 expression, increased LC3-II accumulation, elevated Drp1 expression, and reduced Opa1 expression, whereas TMAS significantly reversed these abnormalities, suggesting restoration of mitophagy-related mitochondrial quality control and re-establishment of mitochondrial fission-fusion balance. Collectively, these findings indicate that TMAS ameliorates MPTP-induced neurotoxicity and restores mitochondrial homeostasis and energy metabolism. ConclusionTMAS effectively attenuates neural damage and improves motor dysfunction in MPTP-induced PD mice. Its neuroprotective effects are closely associated with multidimensional regulation of the mitochondrial quality control system, including restoration of PINK1/Parkin-mediated mitophagy and rebalancing of Drp1/Opa1-related mitochondrial dynamics. Rather than acting only as a symptomatic neuromodulatory intervention, TMAS may influence a key pathological axis of PD by improving mitochondrial homeostasis in SNc and protecting nigral dopaminergic neurons. These findings provide experimental evidence supporting TMAS as a promising non-invasive physical intervention for PD.
2.Influencing Factors of Depression in Patients with Postoperative Ovarian Cancer
Jialiang YAO ; Long ZHANG ; Jianhui TIAN ; Ze LIU ; Yun YANG ; Yiyang ZHOU ; Minghua LI ; Wang YAO ; Wenfei SHI ; Xinyi LU ; Pan YU ; Enchao CONG
Cancer Research on Prevention and Treatment 2026;53(5):349-359
Objective To explore the prevalence of depressive symptoms in postoperative patients with ovarian cancer and to analyze its influencing factors from multiple dimensions, including clinical characteristics, psychological factors, and laboratory indicators. Methods A cross-sectional study was conducted, which enrolled 235 postoperative patients with ovarian cancer. Depressive status was assessed using the patient health questionnaire, and the demographic, pathological, and medical record data of the patients were collected using the generalized anxiety disorder scale, Pittsburgh sleep quality index, European organization for research and treatment of cancer quality of life questionnaire core 30, and ECOG performance status score. Peripheral blood tumor marker (CA125), routine blood test, lymphocyte subsets, and serum cytokine levels were measured. Univariate and multivariate binary logistic regression analysis were used for statistical analysis. Results The prevalence of depression in postoperative patients with ovarian cancer was 39.15% (92/235). Univariate analysis showed that ECOG score ≥ 2 points, pain, anxiety, poor sleep quality, low quality of life, low life satisfaction, tumor recurrence, six or more cycles of chemotherapy, as well as higher levels of CA125, NLR, and NAR, and lower hemoglobin levels were significantly associated with depression (all P<0.05). Multivariate binary Logistic regression analysis showed that anxiety (OR=1.975, 95%CI: 1.231-3.170), sleep efficiency (OR=4.181, 95%CI: 1.211-14.43), sleep latency (OR=34.806, 95%CI: 4.258-284.542), ECOG performance status score, cognitive function (OR=0.918, 95%CI: 0.868-0.97), and life satisfaction were independent risk factors for depression (all P<0.05). Laboratory indicators were not independent influencing factors in the multivariate Logistic regression model. Conclusion Depression in postoperative patients with ovarian cancer is influenced by physiological, psychological, and social factors. Clinical management should focus on patients with anxiety, sleep disorders, poor physical condition, and low life satisfaction, and a comprehensive prevention and treatment strategy centered on psychological intervention and taking into account symptom management and social support should be implemented.
3.Molecular characterization analyses of a human metapneumovirus outbreak in Gongshu District of Hangzhou City
Jianyi LIU ; Chenye ZHANG ; Lei ZHAO ; Huiqun SHUAI ; Huanhuan YU ; Qingyu SUN ; Fei LU ; Shengjun XI
Shanghai Journal of Preventive Medicine 2026;38(3):216-220
ObjectiveTo analyze the epidemiological and etiological characteristics of a cluster of human metapneumovirus (HMPV) infection in a kindergarten in Gongshu District of Hangzhou City in May 2024, and to provide reference for the prevention and control of similar outbreaks. MethodsAn on-site investigation was conducted using an epidemiological case investigation form. Throat swab specimens collected from cases were screened for 13 respiratory pathogens using real-time fluorescent polymerase chain reaction (PCR). For HMPV nucleic acid positive specimens, the F gene of HMPV was used as the target gene for amplification and sequencing. The sequencing results were then compared with sequences in GenBank database to determine the virus subtypes and perform phylogenetic analyses. ResultsThe outbreak occurred in a kindergarter junior class with a total of 28 preschoolers and 3 teachers and childcare workers. A total of 11 cases (10 preschoolers and 1 teacher) were identified, including 8 male cases and 3 female cases. Clinical manifestations included fever in all 11 cases (100.00%), cough in 8 cases (72.72%), catarrhal symptoms in 4 cases (36.36%), and headache in 3 cases (27.27%). All symptoms were mild, and no severe cases were observed. A total of 11 throat swab samples were collected. Real-time fluorescent PCR test results showed that 3 samples were positive for HMPV nucleic acid, 2 samples were positive for both HMPV and Streptococcus pneumoniae, and 1 sample was positive for both HMPV and rhinovirus. The sequences of the 6 HMPV nucleic acid positive specimens were amplified and analyzed using specific primers, and all were determined to be HMPV subtype A2b. The F gene fragment sequence showed the highest similarity to PV081665.1/Brazil/2024 (99.65%), and also exhibited high similarity to PP683455.1/Indonesia/2021 (99.48%), PV016275.1/Beijing/2024 (99.31%), and PV052230.1/USA/2024 (99.13%). ConclusionThis cluster of acute respiratory tract infection was caused by HMPV subtype A2b, with co-infection of rhinovirus and Streptococcus pneumoniae. The F gene fragment sequences of the HMPV in this outbreak were highly homologous to those of the A2b strains isolated from Brazil, Beijing, Indonesia, and the the United States.
4.Neuroprotective Effects of Transcranial Magneto-acoustic Stimulation on Parkinson’s Disease Model Mice by Regulating Mitophagy and Mitochondrial Homeostasis
Shuai ZHANG ; Yan-Bin WANG ; Yi-Hao XU ; Jin-Rui MI ; Xiao-Chao LU ; Yu-Chen AN ; Ji-Zhou LIU ; Jia-Qi SUN
Progress in Biochemistry and Biophysics 2026;53(5):1457-1470
ObjectiveTranscranial magneto-acoustic stimulation (TMAS) is an emerging non-invasive neuromodulation technique that may provide a novel non-pharmacological intervention strategy for Parkinson's disease (PD). PD is characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc), leading to motor impairments such as bradykinesia, tremor, and rigidity. Increasing evidence indicates that mitochondrial dysfunction and impaired mitochondrial quality control are central mechanisms underlying dopaminergic neuronal loss. In particular, abnormalities in mitophagy and mitochondrial fission-fusion balance contribute substantially to oxidative stress, energy metabolic failure, and neuronal injury. At present, most clinical treatments for PD mainly alleviate symptoms but do not effectively halt disease progression. Therefore, exploring new interventions targeting the core pathological mechanisms is of considerable significance. This study aims to investigate whether TMAS can improve neural damage and motor dysfunction in PD mice by regulating mitophagy and the fission/fusion dynamic balance, thereby providing theoretical and experimental support for its application in PD treatment. MethodsMale C57BL/6 mice were used in this study. A PD model was established by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 7 consecutive days. After model induction, mice in the intervention group received TMAS once daily for 14 consecutive days, whereas the corresponding control group received sham stimulation. The stimulation target was positioned over the primary motor cortex (M1). Motor performance was evaluated using the pole test and the open-field test. To verify the activation effect of TMAS on the target cortical region, c-Fos immunohistochemistry was performed in the M1. To assess nigral dopaminergic neuronal injury, tyrosine hydroxylase (TH) immunohistochemistry was used to quantify TH-positive neurons in the SNc. Mitochondrial function was evaluated by measuring reactive oxygen species (ROS) levels and adenosine triphosphate (ATP) content in the SNc. Western blot was further performed to determine the expression of mitophagy-related proteins, including PINK1, Parkin, LC3-II, and p62, as well as mitochondrial dynamics-related proteins, including Drp1 and Opa1. ResultsTMAS significantly increased the number of c-Fos-positive cells in M1 (P<0.000 1), indicating effective activation of neurons in the targeted cortical region. Compared with the control group, MPTP-treated mice exhibited marked motor dysfunction, including a significant reduction in total distance traveled in the open-field test (P<0.000 1) and mean speed (P=0.000 1), as well as significant prolongation of turn time and total climbing time in the pole test (P<0.000 1). These behavioral impairments were accompanied by a substantial loss of TH-positive dopaminergic neurons in the SNc, whereas TMAS significantly increased TH-positive neuron survival (P<0.000 1). In parallel, MPTP induced a pronounced increase in ROS levels and a significant reduction in ATP content, indicating severe mitochondrial dysfunction and energy metabolism impairment (P<0.01). TMAS treatment significantly improved motor performance, as reflected by the reversal of MPTP-induced impairment in the open-field and pole tests, and significantly reduced ROS accumulation (P<0.01) while restoring ATP production (P<0.001). At the molecular level, MPTP markedly downregulated PINK1 and Parkin, decreased p62 expression, increased LC3-II accumulation, elevated Drp1 expression, and reduced Opa1 expression, whereas TMAS significantly reversed these abnormalities, suggesting restoration of mitophagy-related mitochondrial quality control and re-establishment of mitochondrial fission-fusion balance. Collectively, these findings indicate that TMAS ameliorates MPTP-induced neurotoxicity and restores mitochondrial homeostasis and energy metabolism. ConclusionTMAS effectively attenuates neural damage and improves motor dysfunction in MPTP-induced PD mice. Its neuroprotective effects are closely associated with multidimensional regulation of the mitochondrial quality control system, including restoration of PINK1/Parkin-mediated mitophagy and rebalancing of Drp1/Opa1-related mitochondrial dynamics. Rather than acting only as a symptomatic neuromodulatory intervention, TMAS may influence a key pathological axis of PD by improving mitochondrial homeostasis in SNc and protecting nigral dopaminergic neurons. These findings provide experimental evidence supporting TMAS as a promising non-invasive physical intervention for PD.
5.Integrated network pharmacology analysis and cellular evidence reveal the mechanisms of Myristica fragrans against atherosclerosis
Shuxian LU ; Zhiling ZHOU ; Yifeng ZHANG ; Jun YU
Acta Universitatis Medicinalis Anhui 2026;61(4):618-627
ObjectiveTo explore the potential mechanisms by which Myristica fragrans prevents and treats atherosclerosis (AS). MethodsThe major active components of Myristica fragrans and their shared targets with AS were obtained from databases. The shared targets were subjected to pathway enrichment analysis and PPI network construction using the ClusterProfile package and the STRING database. Molecular docking between key targets and major active components was performed using AutoDock. Gene expression data from early and late, as well as stable and unstable AS plaques, were used to validate changes of key targets and major pathways during AS progression. Western blot, flow cytometry, YO-PRO-1/PI staining, and TUNEL staining were applied to verify the main mechanisms. ResultsNine active components of Myristica fragrans interacted with 293 AS-related targets, among which eight components acted on an average of 57.0% of the shared targets. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses indicated that the anti-AS effects mainly involved oxidative stress, inflammation, lipid metabolism, fluid shear stress, and apoptosis pathways. PPI network revealed JUN, CASP3, MAPK3, and AKT1 as key targets mainly involved in regulating apoptosis. Molecular docking showed stable binding conformations and high affinities between major components and these targets. Integrated analysis of gene expression in early and late, as well as stable and unstable AS plaques, showed significant enrichment of leukocyte apoptosis pathways in late and unstable plaques. Cell experiments further confirmed that Myristica fragrans significantly reduced Cleaved-CASP3(P=0.04)and p-MAPK3(P=0.000 3)levels, increased p-AKT1(P=0.004)levels, and inhibited macrophage apoptosis. ConclusionMyristica fragrans potentially interferes with AS development by modulating pathways related to oxidative stress, inflammation, lipid metabolism, fluid shear stress, and apoptosis, with CASP3, MAPK3, and AKT1 serving as key targets mediating its anti-apoptotic and anti-AS effects.
6.Efficacy of Zishen Huoxue Formula in treatment of molecular-targeted therapy-associated proteinuria in patients with primary liver cancer
Jing JING ; Aozhe ZHANG ; Simiao YU ; Xin WANG ; Yongqiang SUN ; Yiling WANG ; Ruixin GAO ; Yinying LU ; Xiaohe XIAO ; Ruilin WANG
Journal of Clinical Hepatology 2026;42(4):874-881
ObjectiveTo investigate the effect of Zishen Huoxue Formula (ZSXHF) on molecular-targeted therapy-associated proteinuria in patients with primary liver cancer (PLC), to assess the efficacy of ZSXHF in the treatment of molecular-targeted therapy-associated proteinuria, and to provide a basis for clinical medication. MethodsA retrospective cohort study was conducted among the PLC patients with molecular-targeted therapy-associated proteinuria who were diagnosed and treated in The Department of Hepatology of Chinese PLA General Hospital, from January 1, 2022 to July 1, 2025. With ZSXHF treatment as the exposure factor, the patients with a cumulative treatment duration of ≥9 weeks were enrolled as traditional Chinese medicine (TCM) group, while those without TCM treatment were enrolled as control group. Propensity score matching was performed for the two groups at a ratio of 1∶1 based on sex, age, 24-hour urinary protein, blood urea nitrogen, and serum creatinine. The independent-samples t test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between groups. Univariate and multivariate Logistic regression analyses were used to investigate the influencing factors for promoting the improvement of targeted-therapy-associated proteinuria. ResultsA total of 137 PLC patients with targeted-therapy-associated proteinuria were enrolled, with 34 patients in the TCM group and 103 in the control group. After follow-up for 6 months, the TCM group had a significant improvement in urinary protein grade compared with the control group (χ2=9.261, P=0.016). There were 25 patients in each group after propensity score matching, and after follow-up for 6 months, there were significant differences between the two groups in urinary protein grade (χ2=15.689, P<0.001) and 24-hour urinary protein (Z=-3.075, P=0.002). After cumulative treatment with ZSXHF for ≥9 weeks, the TCM group had a significantly greater change in 24-hour urinary protein from baseline compared with the control group (t=-2.514, P=0.016), while there were no significant differences in the changes in liver and renal function after ZSXHF intervention between the two groups (all P>0.05). The multivariate Logistic regression analysis showed that ZSXHF treatment (odds ratio=2.901, 95% confidence interval: 1.135 — 7.417, P=0.026) was an independent influencing factor for improvement in molecular-targeted therapy-associated proteinuria. ConclusionZSHXF can effectively alleviate molecular-targeted therapy-associated proteinuria in PLC patients with a favorable safety profile, which provides a new reference for TCM prevention and treatment of molecular-targeted therapy-associated adverse reactions in PLC patients.
7.Research progress on relationship and mechanism between shift work and vascular aging
Zeyu YANG ; Yu ZHANG ; Xiaohui LU
Journal of Environmental and Occupational Medicine 2026;43(1):116-125
Shift work, as a form of non-conventional work schedule, significantly increases the risk of vascular aging and related diseases due to circadian rhythm disruption, sleep disturbances, and unhealthy lifestyle behaviors. This review systematically summarized the mechanisms and epidemiological evidence linking shift work to vascular aging. Available studies indicated that shift work disrupts the rhythmic expression of core circadian clock genes (e.g., BMAL1, CLOCK, PER, CRY), leading to dysregulated glucose and lipid metabolism, enhanced oxidative stress, chronic inflammation, and altered diurnal blood pressure patterns, thereby directly impairing endothelial function and accelerating arterial stiffness. Sleep deprivation and fragmentation further reduce nitric oxide bioavailability and promote endothelin-1 secretion, exacerbating vascular constriction and inflammatory responses. Existing epidemiological data show that shift workers exhibit higher prevalence of hypertension, metabolic syndrome, and atherosclerosis compared with non-shift workers, accompanied by abnormal vascular function indicators such as pulse wave velocity and carotid intima-media thickness. Additionally, unhealthy dietary habits, psychological stress, and sedentary behavior in shift workers synergistically contribute to vascular aging. This review aims to provide a theoretical basis for the pathological link between shift work and vascular aging and to inform public health policy formulation and occupational health management.
8.The Growing Burden of Fall-Related Injuries among Older Adults: A Seven-Year Study from a Tertiary Medical Center in Taiwan
Yu-Chieh TSAI ; Shey-Ying CHEN ; Ya-Mei CHEN ; Edward Pei-Chuan HUANG ; Feng-Ping LU
Annals of Geriatric Medicine and Research 2026;30(1):70-76
Background:
As Taiwan’s population ages, falls among older adults have become a critical public health concern. However, limited data exist regarding temporal trends and injury patterns in fall-related emergency department (ED) visits. This study aimed to examine trends in fall-related ED visits and hospitalizations among older adults in Taiwan and to explore injury distributions by age group.
Methods:
We conducted a retrospective cohort study using data from the National Taiwan University Hospital between 2011 and 2017. Patients aged ≥65 years were compared with those aged 20–64 years. Fall-related visits were identified using chief complaints and the International Classification of Diseases 9th/10th revision (ICD-9/ICD-10) codes. Outcomes included hospitalization rates, length of stay, and 30-day mortality.
Results:
A total of 22,471 fall-related ED visits were analyzed. While visits among younger adults declined (annual growth rate, -1.34%), visits among older adults increased (2.37% annually), with the steepest rise in those aged ≥85 years. Hospitalization occurred in 27.1% of older adults, nearly double that of younger adults (14.4%). Older adults also had longer hospital stays and higher 30-day mortality rates, findings consistent even when restricted to lower limb fractures.
Conclusion
Fall-related ED visits and hospitalizations are rising disproportionately among Taiwan’s older population. Targeted prevention strategies and transitional care interventions are urgently needed to address the growing clinical and economic burden of falls in aging societies.
9.Predictive Factors Associated With Dysphagia in Patients With Traumatic Brain Injury
Shu-Mei YANG ; Ting-Ju LAI ; Ya-Chu HSU ; Yu-Lin LU ; Hsing-Yu CHEN ; Hsiao-Ting TSAI ; Sheng-Hao CHENG ; Ming-Yen HSIAO ; Meng-Ting LIN
Annals of Rehabilitation Medicine 2026;50(2):117-128
Objective:
To identify early clinical predictors associated with dysphagia and delayed swallowing recovery in patients with traumatic brain injury (TBI).
Methods:
In this retrospective study, we enrolled adult TBI patients admitted to the rehabilitation unit of a tertiary medical center between June 2019 and June 2023. Data on baseline characteristics, neurological status, imaging findings, and rehabilitation-related variables were collected. Swallowing function was assessed using two indicators: (1) nasogastric (NG) tube retention and (2) the Functional Oral Intake Scale (FOIS) scores at 1, 4, and 12 weeks post-injury. Regression analyses were conducted to identify predictors associated with dysphagia and swallowing recovery.
Results:
A total of 160 patients were included. At 1 week post-injury, longer intensive care unit (ICU) stay, poor initial sitting balance and use of sedative medication in ICU were associated with NG tube retention. At 4 weeks, lower initial Rancho Los Amigos Scale (RLAS) scores, immobility-related complications, longer hospitalization, and temporal lobe hematomas were associated with persistent NG tube dependence. By 12 weeks, older age, delayed ability to follow commands, and poor initial sitting balance remained associated with NG tube retention. FOIS outcomes were also associated with older age, delayed time to follow commands, impaired initial sitting balance, prolonged ICU stay, temporal lobe hematomas, lower initial RLAS scores, immobility-related complications, prolonged endotracheal tube placement and extended hospital stays.
Conclusion
Impaired cognitive status, poor physical function, immobility-related complications, and temporal lobe hematomas were key factors associated with dysphagia and delayed oral intake in individuals with TBI.
10.Three-dimensional finite element analysis of molar distalization with clear aligners with different thicknesses and edges
Yanan CHENG ; Jiazhi YU ; Yinchang LIU ; Jie WU ; Tong YU ; Lu WANG ; Xiaoguang LI
Chinese Journal of Tissue Engineering Research 2026;30(2):310-318
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.

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