Objective To investigate the mechanical effects of various height combinations of canine long-arm hooks and micro-im-plant anchorage on the retraction of maxillary anterior teeth in clear aligner treatment.It focuses on analyzing the stress distribution within the periodontal ligament and the movement tendencies of the anterior teeth,providing scientific evidence for optimizing orthodon-tic treatment strategies.Methods Three-dimensional finite element models were developed using CBCT scan data of patients and soft-ware including Mimics,Geomagic Studio,and Hypermesh.The models incorporated 16 different configurations of canine long-arm hooks(4,6,8,10 mm)and micro-implant anchorage(6,8,10,12 mm).Elastic traction forces of 3/16,3.5 oz were applied to these models.Simulations assessed how these variables influenced periodontal ligament stress distribution and the movement patterns of the maxillary anterior teeth.Results Stress during anterior teeth retraction was predominantly concentrated in the cervical and apex re-gions of the periodontal ligament,where it interfaced with the alveolar bone,indicating significant local concentration.Increasing the height of micro-implant anchorage and traction hooks markedly reduced positional changes in both the crown and apex.Specifically,when hooks exceeded 8 mm and anchorage heights surpassed 10 mm,canine movement became more uniform,preventing extrusion and minimizing the deepening of the overbite.Additionally,combinations of high traction hooks and high micro-implant anchorage promoted more uniform tooth movement,reducing unnecessary tipping and rotation.Conclusion In the retraction of maxillary anterior teeth with clear aligners,using high-position micro-implant anchorage and high-position traction hooks significantly enhances torque control of anterior teeth and effectively prevents deepening of the overbite.

Objective To investigate the mechanical effects of various height combinations of canine long-arm hooks and micro-im-plant anchorage on the retraction of maxillary anterior teeth in clear aligner treatment.It focuses on analyzing the stress distribution within the periodontal ligament and the movement tendencies of the anterior teeth,providing scientific evidence for optimizing orthodon-tic treatment strategies.Methods Three-dimensional finite element models were developed using CBCT scan data of patients and soft-ware including Mimics,Geomagic Studio,and Hypermesh.The models incorporated 16 different configurations of canine long-arm hooks(4,6,8,10 mm)and micro-implant anchorage(6,8,10,12 mm).Elastic traction forces of 3/16,3.5 oz were applied to these models.Simulations assessed how these variables influenced periodontal ligament stress distribution and the movement patterns of the maxillary anterior teeth.Results Stress during anterior teeth retraction was predominantly concentrated in the cervical and apex re-gions of the periodontal ligament,where it interfaced with the alveolar bone,indicating significant local concentration.Increasing the height of micro-implant anchorage and traction hooks markedly reduced positional changes in both the crown and apex.Specifically,when hooks exceeded 8 mm and anchorage heights surpassed 10 mm,canine movement became more uniform,preventing extrusion and minimizing the deepening of the overbite.Additionally,combinations of high traction hooks and high micro-implant anchorage promoted more uniform tooth movement,reducing unnecessary tipping and rotation.Conclusion In the retraction of maxillary anterior teeth with clear aligners,using high-position micro-implant anchorage and high-position traction hooks significantly enhances torque control of anterior teeth and effectively prevents deepening of the overbite.

Objective:To evaluate protective effects of isorhamnetin on mitochondrial structure and function in HaCaT cells under oxidative stress.Methods:HaCaT cells served as the research object, and were divided into 4 groups: control group receiving conventional culture, isorhamnetin group treated with 60 μmol/L isorhamnetin, H 2O 2 group treated with 600 μmol/L H 2O 2, and isorhamnetin + H 2O 2 group pretreated with 60 μmol/L isorhamnetin for 12 hours followed by medium replacement and 12-hour treatment with 600 μmol/L H 2O 2. Flow cytometry was performed to detect cellular reactive oxygen species (ROS) levels, transmission electron microscopy to observe mitochondrial ultrastructure, confocal fluorescence microscopy to evaluate mitochondrial membrane potential, real-time fluorescence-based quantitative PCR (qRT-PCR) to determine the mitochondrial DNA copy number, and adenosine triphosphate (ATP) assay kit was used to determine the mitochondrial ATP content. One-way analysis of variance was used for comparisons among multiple groups, and least significant difference- t test for multiple comparisons. Results:Oxidative stress was provoked in HaCaT cells after the treatment with H 2O 2. Compared with the control group, the H 2O 2 group showed significantly increased ROS levels (10 725.0 ± 845.8 vs. 1 708.0 ± 69.4, t = 18.40, P < 0.001), but significantly decreased fluorescence intensity of mitochondrial membrane potential, mitochondrial ATP content, and expression of ND-1 (a characteristic gene of mitochondrial DNA) ( t = 4.58, 4.48, 6.11, P = 0.010, 0.010, 0.003, respectively). After the pretreatment with isorhamnetin followed by H 2O 2 treatment, the isorhamnetin+ H 2O 2 group showed significantly decreased ROS levels (7 640.0 ± 922.7) compared with the H 2O 2 group ( t = 4.27, P = 0.013), but significantly increased fluorescence intensity of mitochondrial membrane potential, mitochondrial ATP content, and expression of ND-1 compared with the H 2O 2 group ( t = 4.59, 4.58, 5.61, P = 0.010, 0.010, 0.005, respectively). Under the electron microscope, the mitochondrial structure was clearer and more complete in the isorhamnetin+ H 2O 2 group than in the H 2O 2 group; there was slight or no swelling of mitochondrial cristae, and no vacuolization of mitochondria in the isorhamnetin+ H 2O 2 group; in addition, autophagosomes engulfing damaged mitochondria were observed in the isorhamnetin+ H 2O 2 group. Conclusion:Isorhamnetin may reduce ROS levels by inducing autophagy, and has a protective effect against the H 2O 2-induced mitochondrial structural and functional damage in HaCaT cells.

Objective To investigate the effect of improving immunity in the treatment of chronic brucellosis,and to analyze and evaluate its clinical curative effect.Methods A patient with chronic brucellosis was treated with Mongolian medicine combined with chemical drugs to enhance immunity.The clinical symptoms,serological antibodies,Brucella DNA and immune function were compared before and after treatment.The specific antibody against Brucella in serum was detected by tube agglutination test (SAT) and tiger red plate agglutination test (RBPT).Brucella DNA in serum and blood cells was detected by PCR,and the peripheral blood lymphocyte subsets were detected by flow cytometry.Immuno-luminescence technique was used to detect serum immunoglobulin and complement components.Results After treatment,the clinical symptoms such as cold back,fatigue,and joint pain disappeared completely,and the results of serum specific antibodies against Brucella were SAT 1 ∶ 50 (++)and RBPT (+) with no changes before and after treatment,and the results of cells and serum were both negative after treatment though the results of DNA detection of Brucella were cell positive and seronegative before treatment.The results of immunological function test showed that γδT cells decreased to 9.50％ after treatment compared to 14.00％ before treatment,and the percentage of monocytes and Treg cells were 5.59％ and 7.33％ after treatment,which were higher than 3.35％ and 4.72％ of before treatment,and the level of complement C3 was 0.79 g/L before treatment and 0.91 g/L after treatment that was returned to normal reference range (0.88 ～ 2.01 g/L).Conclusion The patients with chronic brucellosis can improve their clinical treatment by improving immunity.

Objective To investigate the effect of MMP-9 on severe acute pancreatitis(SAP) associated with lung injury,and the preventive function of MMP-9 inhibitor (BB-94) in SAP associated with lung injury in rats. Methods SD rats were randomly divided into three groups: Shamed-operated groups (control groups,n=10);SAP groups (n=14);SAP with MMP-9 inhibitor preconditioning groups (BB-94 group,n=15). The samples for test of the wet weigh index of lung,serum amylase level,white cell count,the number of cells and protein in bronchoalveolus lavage fluid,histologic scoring of lung injury and MMP-9 in lung were detected 24 hours after SAP models were set up.Results The parameters mentioned above in SAP group were significant higher than those in controll group and BB-94 group (P