1.Three-dimensional finite element analysis of the mechanical effects of different heights of micro-implant anchorage on maxil-lary anterior teeth retraction in clear aligner treatment
Chi ZHANG ; Leheng ZHANG ; Youran XU ; Fengyang ZHAI ; Peiyu ZHANG ; Liying PIAO ; Minxuan HAN ; Shu LOU
STOMATOLOGY 2025;45(10):742-748,800
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.
2.Three-dimensional finite element analysis of the mechanical effects of different heights of micro-implant anchorage on maxil-lary anterior teeth retraction in clear aligner treatment
Chi ZHANG ; Leheng ZHANG ; Youran XU ; Fengyang ZHAI ; Peiyu ZHANG ; Liying PIAO ; Minxuan HAN ; Shu LOU
STOMATOLOGY 2025;45(10):742-748,800
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.
3.Comparing the effects of clear aligners and fixed braces on the quality of life of adolescent patients
Shu LOU ; Xiaoyan CAI ; Chi ZHANG ; Yuan ZHANG ; Minxuan HAN ; Zhaolan GUAN
STOMATOLOGY 2024;44(11):841-846
Objective To investigate the differences in treatment experience and quality of life between adolescent orthodontic pa-tients using clear aligners and fixed braces.Methods A total of 104 adolescent patients were selected who underwent orthodontic treat-ment with either clear aligners or fixed braces at Nanjing Medical University Affiliated Stomatological Hospital from January 2022 to June 2022.The patients were divided into two treatment groups based on the type of orthodontic appliance,with 52 patients in each group.Within a 6-month period of using clear aligners or fixed braces,adolescent orthodontic patients were surveyed using the child oral health impact profile-short form 19(COHIP-SF19)and other individual items.The differences in mean satisfaction,quality of life,and statistical scores were compared using independent samples t-tests,while the differences in subjective responses were compared using the Wilcoxon rank-sum test.Results There were no significant differences in mean quality of life and statistical scores between the two groups,but patients in the clear aligner group reported higher satisfaction.The clear aligner group reported greater difficulty with eating,while patients with fixed braces were more likely to experience negative emotions.Additionally,there were no significant differences between the two groups in terms of adaptation time to the appliance,maintaining dental hygiene,and feeling attractive.Conclusion Patients in both groups were generally satisfied with their treatment.Adolescent orthodontic patients treated with clear a-ligners or fixed braces for at least 6 months exhibit similar overall quality of life.
4.Predictive Value of Serum Creatinine, Blood Urea Nitrogen, Uric Acid, and β-Microglobulin in the Evaluation of Acute Kidney Injury after Orthotopic Liver Transplantation.
Hai-Yang LU ; Xin-Yu NING ; Ying-Qi CHEN ; Shu-Jun HAN ; Ping CHI ; Sai-Nan ZHU ; Yun YUE
Chinese Medical Journal 2018;131(9):1059-1066
BackgroundAs a major complication after orthotopic liver transplantation (OLT), the occurrence of acute kidney injury (AKI) is frequently defined by serum creatinine (Cr); however, the accuracy of commonly used blood urea nitrogen (BUN), uric acid (UA), and β-microglobulin (β-MG) remains to be explored. This retrospective study compared the accuracy of these parameters for post-OLT AKI evaluation.
MethodsPatients who underwent OLT in three centers between July 2003 and December 2013 were enrolled. The postoperative AKI group was diagnosed by the Kidney Disease Improving Global Outcomes (KDIGO) criteria and classified by stage. Measurement data were analyzed using the t-test or Wilcoxon rank-sum test; enumerated data were analyzed using the Chi-square test or Fisher's exact test. Diagnostic reliability and predictive accuracy were evaluated using receiver operating characteristic (ROC) curve analysis.
ResultsThis study excluded 976 cases and analyzed 697 patients (578 men and 119 women); the post-OLT AKI incidence was 0.409. Compared with the no-AKI group, the AKI group showed very significant differences in Model for End-stage Liver Disease score (14.74 ± 9.91 vs. 11.07 ± 9.54, Z = 5.404; P < 0.001), hepatic encephalopathy (45 [15.8%] vs. 30 [7.3%], χ = 12.699; P < 0.001), hemofiltration (28 [9.8%] vs. 0 [0.0%], χ = 42.171; P < 0.001), and 28-day mortality (23 [8.1%] vs. 9 [2.2%], χ = 13.323; P <0.001). Moreover, mean values of Cr, BUN, UA, and β-MG in the AKI group differed significantly at postoperative days 1, 3, and 7 (all P < 0.001). ROC curve area was 0.847 of Cr for the detection of AKI Stage 1 (sensitivity 80.1%, specificity 75.7%, cutoff value 88.23 μmol/L), 0.916 for Stage 2 (sensitivity 87.6%, specificity 82.6%, cutoff value 99.9 μmol/L), and 0.972 for Stage 3 (sensitivity 94.1%, specificity 88.2%, cutoff value 122.90 μmol/L).
ConclusionThe sensitivity and specificity of serum Cr might be a high-value indicator for the diagnosis and grading of post-OLT AKI.
Acute Kidney Injury ; blood ; Adult ; Blood Urea Nitrogen ; Creatinine ; blood ; Female ; Humans ; Liver Transplantation ; Male ; Middle Aged ; Retrospective Studies ; Uric Acid ; blood ; beta 2-Microglobulin ; blood
5.Acute and Chronic Changes and Predictive Value of Tpeak-Tend for Ventricular Arrhythmia Risk in Cardiac Resynchronization Therapy Patients.
Cong XUE ; Wei HUA ; Chi CAI ; Li-Gang DING ; Zhi-Min LIU ; Xiao-Han FAN ; Yun-Zi ZHAO ; Shu ZHANG
Chinese Medical Journal 2016;129(18):2204-2211
BACKGROUNDProlongation of the Tpeak-Tend (TpTe) interval as a measurement of transmural dispersion of repolarization (TDR) is an independent risk factor for chronic heart failure mortality. However, the cardiac resynchronization therapy's (CRT) effect on TDR is controversial. Therefore, this study aimed to evaluate CRTs acute and chronic effects on repolarization dispersion. Furthermore, we aimed to investigate the relationship between TpTe changes and ventricular arrhythmia.
METHODSThe study group consisted of 101 patients treated with CRT-defibrillator (CRT-D). According to whether TpTe was shortened, patients were grouped at immediate and 1-year follow-up after CRT, respectively. The echocardiogram index and ventricular arrhythmia were observed and compared in these subgroups.
RESULTSFor all patients, TpTe slightly increased immediately after CRT-D implantation, and then decreased at the 1-year follow-up (from 107 ± 23 to 110 ± 21 ms within 24 h, to 94 ± 24 ms at 1-year follow-up, F = 19.366,P< 0.001). No significant difference in the left ventricular reverse remodeling and ventricular tachycardia/ventricular fibrillation (VT/VF) episodes between the TpTe immediately shortened and TpTe immediately nonshortened groups. However, patients in the TpTe at 1-year shorten had a higher rate of the left ventricular (LV) reverse remodeling (65% vs. 44%, χ2 = 4.495, P = 0.038) and less VT/VF episodes (log-rank test, χ2 = 10.207, P = 0.001) compared with TpTe 1-year nonshortened group. TpTe immediately after CRT-D independently predicted VT/VF episodes at 1-year follow-up (hazard ratio [HR], 1.030; P = 0.001).
CONCLUSIONSPatients with TpTe shortened at 1-year after CRT had a higher rate of LV reverse remodeling and less VT/VF episodes. The acute changes of TpTe after CRT have minimal value on mechanical reverse remodeling and ventricular arrhythmia.
Aged ; Arrhythmias, Cardiac ; etiology ; Cardiac Resynchronization Therapy ; adverse effects ; Female ; Heart Ventricles ; pathology ; physiopathology ; Humans ; Male ; Middle Aged ; Retrospective Studies
6.Sequence Analysis of A Novel HLA-B*13:68 Allele.
Bin HAN ; Li HAN ; Zhi-Hui FENG ; Xiao-Yun CHI ; Shu-Xian JIAO
Journal of Experimental Hematology 2015;23(4):1144-1146
OBJECTIVEThe purpose of this research was to identify a novel HLA-B allele in Chinese population.
METHODSThe HLA typing of bone marrow donors was performed by PCR-SBT. The ambiguous novel HLA allele was confirmed with GSSP method.
RESULTSThe sequence of a sample was different from all alleles in the HLA-B databases. The sequence analysis showed that it differed from the closet matching allele HLA-B*13:01:01 at one nucleotide substitution, 137 T > C in Exon2, which resulted in an amino acid change from Phenylalanine (Phe) to Serine (Ser) at codon 22.
CONCLUSIONA novel allele was identified and named as HLA-B*13:68 by the WHO Nomenclature Committee.
Alleles ; Asian Continental Ancestry Group ; Base Sequence ; HLA-B Antigens ; Histocompatibility Testing ; Humans ; Polymerase Chain Reaction ; Sequence Analysis, DNA
7.Effect of early high -volume hemofiltration in the treatment and prognosis of post-resuscitation syndrome
Qian-Long XUE ; Hui WANG ; Ying HE ; Shu-Chi HAN ; Li-Peng YANG ; Yan-Mei CHEN ; Xiu-Qian ZHANG ; Fan LIU
The Chinese Journal of Clinical Pharmacology 2015;31(22):2196-2198
Objective To evaluate the effect of early high -volume hemofiltration in the treatment and prognosis of post -resuscitation syndrome( PRS).Methods A total of 44 patients wiht PRS were ran-domly divided into the trial group and the control group, and all patients were treated by conventional treatment.The patients in the trial group were treated by early high-volume hemofiltration within 6 h, while the patients in the control group were treated by high-volume hemofiltration after 6 h.Acute physiology and chronic health evaluation ( APACHEII) , multiple organ dysfunction syndrome evaluation ( MODS ) , C -reactive protein(CRP), procalcitonin(PCT), dopamine dosage, mean arterial pressure(MAP), and oxygenation index were recorded.Results The APACHE Ⅱ score, MODS score, serum CRP and PCT level improved and dopamine dosage decreased after treatment in two groups compared with those before treatment (P<0.05), but the parameters in trial group were significantly lower than those in control group ( P<0.05) , and MAP and oxygenation index in the trial group were significantly higher than those in the control group ( P <0.05 ) . Conclusion Early high-volume hemofiltration is effective in the treatment and prognosis of PRS with positive significance.
8.Standardized management of acupuncture-moxibustion clinic in Singapore General Hospital.
Shu-Li CUI ; Kian Hian TAN ; Biauw Chi ONG ; Shih hui LIM ; Yang YONG ; Cheng Ngee SEAH ; Youyi HUANG ; Seong Ng HAN
Chinese Acupuncture & Moxibustion 2014;34(2):179-182
The standardized management of acupuncture-moxibustion in Singapore General Hospital is introduced. With gradual improvement of outpatient infrastructure, re-training of medical staff, strict disinfection of manipulation, periodical inspection of medical instruments, unified management of writing, saving and processing in medical records and public education of TCM knowledge, a standardized management system in accordance with modernized hospital is gradually established. As a result, efficiency and quality of clinical treatment is continuously increasing. From April of 1998 to December of 2012, a total of 74 654 times of treatment were performed, and treatment amount per day is gradually increased. The unusual condition of acupuncture is avoided. Periodical strict inspection of joint committee authenticated by domestic and overseas medical health organization is repeatedly passed and accepted. Additionally, three clinical researches funded by Singapore Health-care Company are still in progress in acupuncture-moxibustion department.
Acupuncture Therapy
;
standards
;
Hospitals, General
;
manpower
;
organization & administration
;
standards
;
Humans
;
Moxibustion
;
standards
;
Practice Management, Medical
;
organization & administration
;
standards
;
Reference Standards
;
Singapore
9.Finite Element analysis on space closure of central incisors using invisible appliance with different material hardness
Shu-chi XIA ; Yan-qin LU ; Jing-yun HAN ; Lin XU ; Zi-yi XIAO
Journal of Medical Biomechanics 2013;28(6):E654-E658
Objective To analyze the mechanical effect of invisible appliances with different material hardness and provide theoretical basis for selecting the suitable material for invisible appliance and its clinical application. Methods Three different three-dimensional (3D) finite element models of invisible appliance were established, of which the elastic modulus was chosen as 415.6, 816.308 and 2 400 MPa, respectively. In these models, the upper central incisors were all designed to move 0.3 mm mesially. Then 3D nonlinear finite element method was used to analyze the stress-distribution in invisible appliance, teeth and periodontal ligament and the instant displacement of every tooth. The comparative study was made among three invisible appliances with different hardness. Results Under experimental condition, the most instant stress and displacement of teeth was the upper central incisor, with initial displacement greater in crown section than that in apical section and the greatest displacement was 0.17 mm. The tendency of central incisor movement was tipping in all situations. The movement of lateral incisor had the second greatest distance (the greatest displacement was 0.10 mm) and the tendency of its movement was in the opposite directions of aimed teeth. When elastic modulus of material decreased, the stress on the invisible appliance increased. The stress in periodontal ligament and the displacement of aimed teeth were also increased. Conclusions If the hardness of invisible appliance increases, the displacement of the designed tooth and treatment efficacy increases, but the appliance with more hardness couldn’t provide better ability in controlling of orthodontic tooth movement. The study suggested clinicians should use attachments or cooperate with fixed appliance to help move teeth bodily.
10.Numerical and experimental study on steady flow in the model of internal carotid artery siphon
Chi ZHANG ; Jing-yun HAN ; Fang PU ; Shu-yu LI ; Yu-bo FAN ; De-yu LI
Journal of Medical Biomechanics 2013;28(1):E056-E062
Objective To investigate the hemodynamic factors in internal carotid arteries (ICA) with different shapes, and analyze the relationship between the arterial geometry and atherosclerotic stenosis to provide the hemodyanmic basis for the risk prediction and early diagnosis of ICA stenosis. Methods The flow field in the most two common types of ICAs, U and V-shaped ICA, were investigated by numerical simulation and particle image velocimetry (PIV) experiment under the condition of steady flow. Results At the upstream bend of ICA, the hemodynamic factors were monotonically associated with the curvature of the bend. As a result, the risk for stenosis here was smaller in the V-shaped ICA, as compared to U-shaped ICA. But at the downstream bend, such monotonic relationship didn’t exist due to the synergistic effect of the two bends. ConclusionsThe curvature of the artery is positively related to the risk for stenosis, but the synergistic effect of bends needs to be considered for studying arteries with the serial bends. The research on the synergistic effect may explain why the stenosis is frequently observed in arteries with multiple bends.

Result Analysis
Print
Save
E-mail