1.True vertical intrusion of mandibular incisors with torque control using clear aligners: a finite element analysis
XU Changxi ; YE Panpan ; BI Yilin ; WANG Hongning
Journal of Prevention and Treatment for Stomatological Diseases 2025;33(10):841-851
Objective:
This study investigated the effect of applying different torque values on the sagittal displacement tendency of mandibular incisors during intrusion using clear aligners, with the aim of providing a reference for achieving true vertical intrusion (intrusion without labiolingual movement) of mandibular incisors in clear aligner therapy.
Methods:
This study was approved by the institutional ethics committee. A volunteer with an incisor mandibular plane angle of 94° was selected. Using cone-beam computed tomography and intraoral scan data, a high-precision three-dimensional finite element model was established. An intrusion amount of 0.2 mm was set for the mandibular incisors, and four simulation groups were defined by applying 0°, 1°, 2°, and 3° of root labial torque. The displacement tendency of the incisors and the stress distribution within the periodontal ligament were analyzed.
Results:
When 0° of root labial torque was applied, the mandibular incisors exhibited intrusion accompanied by crown-labial, root-lingual inclination. When 1°-3° of root labial torque was applied, the mandibular incisors exhibited intrusion accompanied by the inclination gradually shifted from crown-labial, root-lingual towards crown-lingual, root-labial. Based on the line graph of sagittal displacement, the central incisors and lateral incisors approximated true vertical intrusion when 1.8° and 2.5° of root labial torque was applied, respectively. The mandibular canines consistently exhibited extrusion accompanied by labial crown inclination. Stress within the periodontal ligament of the incisors and canines was primarily concentrated at the root apex and cervical region. After applying root labial torque, the area of stress concentration in the incisors cervical periodontal ligament shifted from the labial side to the lingual side. The stress in the periodontal ligament at the cervical region of the canines is predominantly concentrated on the labial side.
Conclusion
Applying appropriate torque control during mandibular incisor intrusion with clear aligners facilitates true vertical intrusion, thereby enhancing the efficiency of the intrusion.
2.Finite element analysis on miniscrews and hooks with different locations assisted clear aligners in maxillary molar distalization
Panpan YE ; Changxi XU ; Hui LI ; Yang ZHANG ; Xiaolin XU ; Hongning WANG
Chinese Journal of Tissue Engineering Research 2025;29(28):6012-6019
BACKGROUND:The utilization of miniscrews for assisting in molar distalization with clear aligners is a commonly adopted clinical approach.However,treatment outcomes may be influenced by the implantation position of miniscrew and the hooks in various tooth location.OBJECTIVE:To analyze the biomechanical effects of hooks at different tooth positions and the assistance of buccal and palatal miniscrews in distalizing molars with clear aligners by using the finite element method.METHODS:By integrating volunteer cone beam CT and Itero intraoral scan data,high-precision finite element models were constructed to simulate the combined use of miniscrews and hooks to assist in the distalization of the maxillary first and second molars with clear aligners,aiming for a designed distalization magnitude of 0.2 mm.Four conditions were established based on the placement of buccal or palatal miniscrews,as well as the located of hooks at the canine or first premolar.The buccal anchorage screw was used in combination with hooks on the buccal side of the canine;the buccal anchorage screw was used in combination with hooks on the buccal side of the first premolar;the palatal anchorage screw was used in combination with hooks on the lingual side of the canine,and the palatal anchorage screw was used in combination with hooks on the lingual side of the first premolar.Analysis using ANSYS software was conducted to evaluate the three-dimensional displacement trends of maxillary teeth and the maximum equivalent stress on the periodontal ligament under each condition.RESULTS AND CONCLUSION:(1)Regardless of whether hooks were placed on canines or first premolars,palatal miniscrews had been shown to enhance the distal movement of maxillary molars and reduce the mesial movement of premolars as well as the labial tipping tendency of anterior teeth,compared to buccal miniscrews.The maximum equivalent stress in the periodontal ligament of molars was increased,while that of anterior teeth was decreased.(2)Regardless of whether the miniscrews were located on the buccal or palatal side,compared with hooks at the first premolar,when hooks were done at the canine,the labial inclination trend of the anterior teeth was reduced,the distal movement of the molars was reduced,the mesial movement of the premolars was increased,and the maximum equivalent stress of the molar and the periodontal membrane of the anterior teeth was reduced.(3)Regardless of whether miniscrews were located on the buccal or palatal side,and the hooks were located on the canine or the first premolar,the molar could not achieve overall movement.(4)The results show that clear aligner combined with palatal miniscrews and hooks at the first premolar are more conducive to improving the efficiency of maxillary molar distalization,but attention should be paid to protecting the anterior tooth miniscrews and molar torque control;clear aligner combined with palatal miniscrews and hooks at the canine is more conducive to reducing the labial tipping tendency of anterior teeth,but the efficiency of molar distalization will be relatively reduced.
3.A practice guideline for therapeutic drug monitoring of mycophenolic acid for solid organ transplants.
Shuang LIU ; Hongsheng CHEN ; Zaiwei SONG ; Qi GUO ; Xianglin ZHANG ; Bingyi SHI ; Suodi ZHAI ; Lingli ZHANG ; Liyan MIAO ; Liyan CUI ; Xiao CHEN ; Yalin DONG ; Weihong GE ; Xiaofei HOU ; Ling JIANG ; Long LIU ; Lihong LIU ; Maobai LIU ; Tao LIN ; Xiaoyang LU ; Lulin MA ; Changxi WANG ; Jianyong WU ; Wei WANG ; Zhuo WANG ; Ting XU ; Wujun XUE ; Bikui ZHANG ; Guanren ZHAO ; Jun ZHANG ; Limei ZHAO ; Qingchun ZHAO ; Xiaojian ZHANG ; Yi ZHANG ; Yu ZHANG ; Rongsheng ZHAO
Journal of Zhejiang University. Science. B 2025;26(9):897-914
Mycophenolic acid (MPA), the active moiety of both mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS), serves as a primary immunosuppressant for maintaining solid organ transplants. Therapeutic drug monitoring (TDM) enhances treatment outcomes through tailored approaches. This study aimed to develop an evidence-based guideline for MPA TDM, facilitating its rational application in clinical settings. The guideline plan was drawn from the Institute of Medicine and World Health Organization (WHO) guidelines. Using the Delphi method, clinical questions and outcome indicators were generated. Systematic reviews, Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence quality evaluations, expert opinions, and patient values guided evidence-based suggestions for the guideline. External reviews further refined the recommendations. The guideline for the TDM of MPA (IPGRP-2020CN099) consists of four sections and 16 recommendations encompassing target populations, monitoring strategies, dosage regimens, and influencing factors. High-risk populations, timing of TDM, area under the curve (AUC) versus trough concentration (C0), target concentration ranges, monitoring frequency, and analytical methods are addressed. Formulation-specific recommendations, initial dosage regimens, populations with unique considerations, pharmacokinetic-informed dosing, body weight factors, pharmacogenetics, and drug-drug interactions are covered. The evidence-based guideline offers a comprehensive recommendation for solid organ transplant recipients undergoing MPA therapy, promoting standardization of MPA TDM, and enhancing treatment efficacy and safety.
Mycophenolic Acid/administration & dosage*
;
Drug Monitoring/methods*
;
Humans
;
Organ Transplantation
;
Immunosuppressive Agents/administration & dosage*
;
Delphi Technique
4.Finite element analysis on miniscrews and hooks with different locations assisted clear aligners in maxillary molar distalization
Panpan YE ; Changxi XU ; Hui LI ; Yang ZHANG ; Xiaolin XU ; Hongning WANG
Chinese Journal of Tissue Engineering Research 2025;29(28):6012-6019
BACKGROUND:The utilization of miniscrews for assisting in molar distalization with clear aligners is a commonly adopted clinical approach.However,treatment outcomes may be influenced by the implantation position of miniscrew and the hooks in various tooth location.OBJECTIVE:To analyze the biomechanical effects of hooks at different tooth positions and the assistance of buccal and palatal miniscrews in distalizing molars with clear aligners by using the finite element method.METHODS:By integrating volunteer cone beam CT and Itero intraoral scan data,high-precision finite element models were constructed to simulate the combined use of miniscrews and hooks to assist in the distalization of the maxillary first and second molars with clear aligners,aiming for a designed distalization magnitude of 0.2 mm.Four conditions were established based on the placement of buccal or palatal miniscrews,as well as the located of hooks at the canine or first premolar.The buccal anchorage screw was used in combination with hooks on the buccal side of the canine;the buccal anchorage screw was used in combination with hooks on the buccal side of the first premolar;the palatal anchorage screw was used in combination with hooks on the lingual side of the canine,and the palatal anchorage screw was used in combination with hooks on the lingual side of the first premolar.Analysis using ANSYS software was conducted to evaluate the three-dimensional displacement trends of maxillary teeth and the maximum equivalent stress on the periodontal ligament under each condition.RESULTS AND CONCLUSION:(1)Regardless of whether hooks were placed on canines or first premolars,palatal miniscrews had been shown to enhance the distal movement of maxillary molars and reduce the mesial movement of premolars as well as the labial tipping tendency of anterior teeth,compared to buccal miniscrews.The maximum equivalent stress in the periodontal ligament of molars was increased,while that of anterior teeth was decreased.(2)Regardless of whether the miniscrews were located on the buccal or palatal side,compared with hooks at the first premolar,when hooks were done at the canine,the labial inclination trend of the anterior teeth was reduced,the distal movement of the molars was reduced,the mesial movement of the premolars was increased,and the maximum equivalent stress of the molar and the periodontal membrane of the anterior teeth was reduced.(3)Regardless of whether miniscrews were located on the buccal or palatal side,and the hooks were located on the canine or the first premolar,the molar could not achieve overall movement.(4)The results show that clear aligner combined with palatal miniscrews and hooks at the first premolar are more conducive to improving the efficiency of maxillary molar distalization,but attention should be paid to protecting the anterior tooth miniscrews and molar torque control;clear aligner combined with palatal miniscrews and hooks at the canine is more conducive to reducing the labial tipping tendency of anterior teeth,but the efficiency of molar distalization will be relatively reduced.
5.Clinical analysis of rejection after pediatric kidney transplantation
Jinghong TAN ; Wenrui WU ; Huanxi ZHANG ; Bowen XU ; Yongcheng WEI ; Jun LI ; Qian FU ; Chenglin WU ; Longshan LIU ; Changxi WANG
Chinese Journal of Organ Transplantation 2023;44(2):75-80
Objective:To explore the morbidity features and therapeutic outcomes of rejections in pediatric kidney transplantation (KT) recipients.Methods:Between January 2013 and June 2022, 360 children undergoing KT were recruited.The relevant clinical data were collected for examining the morbidity features and therapeutic outcomes of rejections.The serum levels of creatinine were compared among groups by non-parametric rank test.And Kaplan-Meier and Log-rank methods were employed for examining the incidence of rejection and comparing mortality-censored graft survival rates among patients with different times of rejection.Results:A total of 58 recipients had 82 incidents of rejection with a cumulative incidence of 6.3%, 9.2% and 11.3% at 3/6/12 months respectively.Among 50 incidents of biopsy-proved rejections, the types were T cell-mediated rejection [TCMR, 42.0%(21/50)], antibody-mediated rejection [20.0%(10/50), ABMR] and mixed rejection [38.0%(19/50)].Among 58 incidents of initial rejection, 69% had maintained graft function (MGF) and 31% impaired graft function (IGF) after anti-rejection regimens.Among 80.8%, 85.7% and 75% of recipients with clinical rejection, ABMR or borderline rejection while 36.4% in TCMR patients had MGF.Fifteen kidney allografts lost function in 58 recipients with rejection.Five-year death-censored graft survival was significantly lower in patients with two or more incidents of rejection (30.5%, 95% CI: 12.3%-75.4%) than in those without rejection (92.9%, 95% CI: 89.3%-96.6%) ( P<0.000 1) or with only one rejection (82.9%, 95% CI: 65.9%-100%)( P<0.001). Conclusions:The rejection rate remains high in KT children and it affects graft survival.And TCMR is more likely to cause impaired graft function.Recurrent rejections have a more pronounced impact upon graft survival.
6.Phenytoin sodium in the treatment of tacrolimus poisoning caused by paxlovid after kidney transplantation: a report of 2 cases
Xueyin XU ; Qian FU ; Chenglin WU ; Huanxi ZHANG ; Jun LI ; Pan CHEN ; Changxi WANG
Chinese Journal of Organ Transplantation 2023;44(8):496-498
This report describs 2 domestic cases of tacrolimus poisoning in kidney transplant recipients due to overexposure of tacrolimus caused by nirmatrelvir/ritonavir for SARS-CoV-2 infection.Phenytoin sodium is prescribed for inducing CYP3A enzyme.It is intended for providing references for formulating and adjusting treatment protocols for tacrolimus overexposure and related toxicity in kidney transplant recipients caused by nirmatrelvir/ritonavir.
7.Retrospective analysis of pediatric kidney transplantation: a report of 244 cases
Huanxi ZHANG ; Jun LI ; Mingchuan HUANG ; Shenghui WU ; Qian FU ; Longshan LIU ; Ronghai DENG ; Chenglin WU ; Bowen XU ; Lizhong CHEN ; Jiang QIU ; Guodong CHEN ; Gang HUANG ; Jiguang FEI ; Suxiong DENG ; Changxi WANG
Chinese Journal of Organ Transplantation 2020;41(1):9-14
Objective:To explore the clinical characteristics and outcomes of pediatric kidney transplantations at a single center and discuss the related clinical issues.Methods:From January 1990 to October 2019, clinical data were analyzed retrospectively for 244 pediatric renal transplants. The youngest recipient was aged 1.8 years and the median age of pediatric recipients was 12.2 years. The major disease was primary or hereditary glomerulonephritis ( n=160, 69.0%), congenital anomalies of kidney and urinary tract (CAKUT), cystic renopathy and other hereditary nephropathies ( n=55, 23.7%). The donor sources included traditional deceased donor ( n=42, 17.2%), living-related donor ( n=19, 7.8%) and organ donation ( n=183, 75.0%). The median age of donors was 2 years (0-51) and the median weight 12.0(2.7-72.0) kg. From January 2013 to October 2019, 170 cases), the major induction immunosuppression regimen was anti-thymocyte globulin (ATG) ( n=110, 64.7%) or basiliximab ( n=58, 34.1%). The maintenance regimen was tacrolimus + mycophenolic acid (MPA) + glucocorticosteroids. Finally the outcomes and the complications were analyzed. Results:The survival rates of 244 kidney allograft recipients were 98.1%, 94.5% and 93.4% and the graft survival rates 92.6%, 84.2% and 82.0% at 1/3/5 years respectively. Ten recipients died of accident ( n=2, 20.0%), pneumonia after transplantation ( n=2, 20.0%) and intracranial hemorrhage ( n=2, 20.0%). Thirty-three recipients lost their allografts mainly due to intravascular thrombosis in graft ( n=5, 14.3%), acute rejection ( n=5, 14.3%) and death ( n=9, 25.7%). Besides, among 109 deceased donor allograft recipients, the postoperative outcomes were delayed graft function recovery (DGF) ( n=27, 24.8%), arterial thrombosis ( n=6, 5.5%), venous thrombosis ( n=1, 0.9%), graft perirenal hematoma ( n=6, 5.5%), raft artery stenosis ( n=10, 9.2%) and graft ureteral fistula ( n=1, 0.9%). The incidence of acute rejection was 17.5% and 23.2% at 1/3 year respectively. The recurrent rate of primary disease was 6.9%, including primary FSGS ( n=3, 42.9%) and IgA nephropathy ( n=2, 28.6%). At 1/3 year post-operation, the incidence of pulmonary infection was 16.9% and 22.4% and the incidence of urinary tract infection 26.9% and 31.7%. Excluding recipients with graft failure, the estimated glomerular filtration rate (eGFR) at 1/2/3 year postoperatively was (80.3±25.2), (81.4±27.8) and (71.8±27.6) ml/(min·1.73 m 2)respectively. Conclusions:The outcomes of pediatric renal transplantations are excellent at our center. Future efforts shall be devoted to optimizing the strategies of donor kidney selection and strengthening preoperative evaluations, perioperative and postoperative managements for improving the long-term outcomes of pediatric renal transplantations.
8.Preliminary results of multicenter studies on ABO-incompatible kidney transplantation
Hongtao JIANG ; Tao LI ; Kun REN ; Xiaohua YU ; Yi WANG ; Shanbin ZHANG ; Desheng LI ; Huiling GAN ; Houqin LIU ; Liang XU ; Zhigang LUO ; Peigen GUI ; Xiangfang TAN ; Bingyi SHI ; Ming CAI ; Xiang LI ; Junnan XU ; Liang XU ; Tao LIN ; Xianding WANG ; Hongtao LIU ; Lexi ZHANG ; Jianyong WU ; Wenhua LEI ; Jiang QIU ; Guodong CHEN ; Jun LI ; Gang HUANG ; Chenglin WU ; Changxi WANG ; Lizhong CHEN ; Zheng CHEN ; Jiali FANG ; Xiaoming ZHANG ; Tongyi MEN ; Xianduo LI ; Chunbo MO ; Zhen WANG ; Xiaofeng SHI ; Guanghui PEI ; Jinpeng TU ; Xiaopeng HU ; Xiaodong ZHANG ; Ning LI ; Shaohua SHI ; Hua CHEN ; Zhenxing WANG ; Weiguo SUI ; Ying LI ; Qiang YAN ; Huaizhou CHEN ; Liusheng LAI ; Jinfeng LI ; Wenjun SHANG ; Guiwen FENG ; Gang CHEN ; Fanjun ZENG ; Lan ZHU ; Jun FANG ; Ruiming RONG ; Xuanchuan WANG ; Guisheng QI ; Qiang WANG ; Puxun TIAN ; Yang LI ; Xiaohui TIAN ; Heli XIANG ; Xiaoming PAN ; Xiaoming DING ; Wujun XUE ; Jiqiu WEN ; Xiaosong XU
Chinese Journal of Organ Transplantation 2020;41(5):259-264
Objective:To summarize the patient profiles and therapeutic efficacies of ABO-incompatible living-related kidney transplantations at 19 domestic transplant centers and provide rationales for clinical application of ABOi-KT.Methods:Clinical cases of ABO-incompatible/compatible kidney transplantation (ABOi-KT/ABOc-KT) from December 2006 to December 2009 were collected. Then, statistical analyses were conducted from the aspects of tissue matching, perioperative managements, complications and survival rates of renal allograft or recipients.Results:Clinical data of 342 ABOi-KT and 779 ABOc-KT indicated that (1) no inter-group differences existed in age, body mass index (BMI), donor-recipient relationship or waiting time of pre-operative dialysis; (2) ABO blood type: blood type O recipients had the longest waiting list and transplantations from blood type A to blood type O accounted for the largest proportion; (3) HLA matching: no statistical significance existed in mismatch rate or positive rate of PRA I/II between two types of surgery; (4) CD20 should be properly used on the basis of different phrases; (5) hemorrhage was a common complication during an early postoperative period and microthrombosis appeared later; (6) no difference existed in postoperative incidence of complications or survival rate of renal allograft and recipients at 1/3/5/10 years between ABOi-KT and ABOc-KT. The acute rejection rate and serum creatinine levels of ABOi-KT recipients were comparable to those of ABOc-KT recipients within 1 year.Conclusions:ABOi-KT is both safe and effective so that it may be applied at all transplant centers as needed.
9. Predictive value of serum glycosylated hemoglobin for the onset of nonalcoholic fatty liver disease
Changxi CHEN ; Juan DU ; Yimin XU ; Jixiao HAN ; Zhongwei ZHU ; Yushan MAO ; Chuanyong GUO
Chinese Journal of Hepatology 2018;26(10):765-770
Objective:
To discuss the affect of glycosylated hemoglobin (HbA1c) level for the onset of nonalcoholic fatty liver disease (NAFLD) in cohort population.
Methods:
An epidemiological survey of the relationship between HbA1c and NAFLD conducted in 2012 was based at cohort baseline, and three follow-up sessions conducted in 2013, 2014 and 2015. In total 2 811 subjects were included in the study after exclusion of NAFLD patients at baseline and those who lost their lives due to relocation, and death. The Cox proportional hazard model was used to analyze the relationship between glycosylated hemoglobin and other risk factors of NAFLD. Continuous variables were compared using the
10.Protective effects of shenfu injection on cerebral ischemia reperfusion injury in rats
Changxi LI ; Lifeng WU ; Guirong ZENG ; Zhengang SHI ; Xiangzhong YUAN ; Yongxing XU ; Miaohong ZHANG
Journal of Chinese Physician 2018;20(10):1487-1490
Objective To study the protective effect of shenfu injection on cerebral ischemia reperfusion injury in rats.Methods 120 male Sprague Dawley (SD) rats(320-350 g) were randomly divided into sham operation group,model control group,Nimodipine injection group,low,medium and high dose group of shenfu injection according to gender weight.20 males in each group were given medicine once a day for 7 days before operation.The cerebral ischemia model was established by thread embolization after 5 days of administration.In the sham operation group,the other operations were the same as those in the model group except for carotid artery ligation and thread insertion.After 24 hours of perfusion,the neurological score,abdominal aorta blood flow,malondialdehyde (MDA),superoxide dismutase (SOD) and glutathione (GHS) levels in brain tissues were measured.Triphenyltetrazolium chloride (TTC) staining was used to calculate the area of cerebral infarction and pathological examination of brain tissues.Results Compared with the model control group,the middle and high dosage of shenfu injection could obviously improve the nerve function and increase the percentage of cerebral infarction area (P < 0.05);the high dosage group of shenfu injection could obviously decrease the whole blood viscosity (P < 0.01);the middle and high dosage of shenfu injection could obviously reduce the level of MDA in rat brain tissue (P < 0.01) while increasing the levels of SOD and GSH (P <0.01),finally could significantly improve the pathological changes of brain tissues such as mild swelling of nerve fibers,mild neuronal degeneration,inflammatory interstitial edema and inflammation.Conclusions Shenfu injection has obvious protective effect on cerebral ischemia reperfusion model in rats.


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