1.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.
2.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.
3.Three-dimensional binding treatment for avulsion fractures of inferior pole of patella utilizing suture anchor.
Hongqing HE ; Ningkai LI ; Meng LIU ; Jiating LIN ; Qiang WANG ; Yinchang ZHANG
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(1):26-31
OBJECTIVE:
To explore the feasibility and effectiveness of suture anchor double-pulley technique combined with suture three-dimensional binding via bone tunnel technique for avulsion fractures of the inferior pole of the patella.
METHODS:
A clinical data of 38 patients with avulsion fractures of the inferior pole of the patella, who met the selective criteria and were admitted between September 2021 and April 2023, was retrospectively analyzed. The fractures were treated with suture anchor double-pulley technique combined with suture three-dimensional binding via bone tunnel technique in 18 cases (group A) and steel wire tension-band fixation in 20 cases (group B). There was no significant difference in terms of age, gender, cause of fracture, side of fracture, and disease duration between the two groups ( P>0.05). The length of incision, operation time, occurrence of complications, the range of motion of knee joint, and Böstman score of knee joint at last follow-up were recorded. The fracture healing was evaluated through X-ray films and the time of fracture healing was recorded.
RESULTS:
All incisions healed by first intention. The length of incision was significantly shorter in group A than in group B ( P<0.05). There was no significant difference in the operation time between the two groups ( P>0.05). All patients were followed up 12-24 months (mean, 16.1 months). X-ray films showed that all fractures healed and there was no significant difference in the healing time between the two groups ( P>0.05). At last follow-up, the range of motion and Böstman score of the knee joint in group A were significantly better than those in group B ( P<0.05). During follow-up, 1 patient (5.6%) in group A had one anchor mild prolapse and 3 patients (15.0%) occured internal fixation irritation in group B. But there was no significant difference in the incidence of complications between the two groups ( P>0.05).
CONCLUSION
For the avulsion fractures of the inferior pole of the patella, the suture anchor double-pulley technique combined with suture three-dimensional binding via bone tunnel technique has advantages of reliable fixation, small incision, avoidance of secondary operation to remove internal fixator, and fewer complications, with definite effectiveness.
Humans
;
Male
;
Female
;
Patella/surgery*
;
Suture Anchors
;
Fracture Fixation, Internal/instrumentation*
;
Adult
;
Retrospective Studies
;
Middle Aged
;
Fractures, Avulsion/surgery*
;
Treatment Outcome
;
Young Adult
;
Range of Motion, Articular
;
Fracture Healing
;
Adolescent
;
Suture Techniques
;
Knee Joint/physiopathology*
4.Effectiveness of composite loop plate around coracoid process for reconstructing coracoclavicular ligament in treatment of Rockwood type Ⅲ acute acromioclavicular joint dislocations.
Hongqing HE ; Ningkai LI ; Meng LIU ; Hua WANG ; Qiang WANG ; Yinchang ZHANG
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(11):1402-1408
OBJECTIVE:
To compare the effectiveness of using a composite loop plate to reconstruct the coracoclavicular ligament around the coracoid process and using a clavicular hook plate for fixation in treatment of Rockwood type Ⅲ acute acromioclavicular joint dislocation.
METHODS:
A retrospective analysis was conducted on the clinical data of 60 patients with Rockwood type Ⅲ acute acromioclavicular joint dislocation who were admitted between June 2022 and September 2023 and met the selection criteria. Among them, 30 patients were treated with the composite loop plate to reconstruct the coracoclavicular ligament around the coracoid process (loop plate group) and 30 with clavicular hook plate fixation (hook plate group). There was no significant difference in baseline data between the two groups ( P>0.05), including gender, age, injured side, cause of injury, disease duration, preoperative visual analogue scale (VAS) score for pain, and Constant-Murley score. The incision length, operation time, length of hospital stay, and the occurrence of complications during follow-up were recorded. The Constant-Murley score and VAS score were used to evaluate shoulder joint function and pain, and the differences (change values) of the indicators between before operation and at 6 months after operation were calculated for inter-group comparison. In the loop plate group, the coracoclavicular distance (CCD) on the anteroposterior X-ray films of the acromioclavicular joint was measured at 1 day and 6 months after operation to assess the loss of acromioclavicular joint reduction.
RESULTS:
The incision length of the loop plate group was significantly shorter than that of the hook plate group ( P<0.05). There was no significant difference in the operation time and the length of hospital stay between the two groups ( P>0.05). All incisions healed by first intention after operation. All patients were followed up 12-18 months (mean, 16.3 months). There was no significant difference in the follow-up time between groups ( P>0.05). The Constant-Murley scores and VAS scores of both groups significantly improved at 6 months after operation when compared with those before operation ( P<0.05); the differences in the change values of the two indicators between groups were significant ( P<0.05). The CCD of the loop plate group were (10.40±0.83) mm at 1 day and (10.70±0.68) mm at 6 months and no repositioning loss was observed. Three cases in the hook plate group had residual shoulder joint pain after operation. The difference in the accidence of complications between groups was not significant ( P>0.05).
CONCLUSION
For Rockwood type Ⅲ acute acromioclavicular joint dislocation, compared with the clavicular hook plate fixation, the composite loop plate for reconstructing the coracoclavicular ligament around the coracoid process has the advantages of simple operation, safety, minimally invasive, good functional recovery, and fewer complications. Moreover, it avoids the need for a second surgery to remove the internal fixation device, and the patient acceptance and satisfaction are higher.
Humans
;
Acromioclavicular Joint/surgery*
;
Bone Plates
;
Male
;
Retrospective Studies
;
Female
;
Adult
;
Ligaments, Articular/injuries*
;
Joint Dislocations/surgery*
;
Coracoid Process/injuries*
;
Treatment Outcome
;
Middle Aged
;
Plastic Surgery Procedures/instrumentation*
;
Fracture Fixation, Internal/instrumentation*
;
Young Adult
;
Clavicle/surgery*
5.A STUDY ON EVALUATION OF EFFICACY OF CHEMOTHERAPY FOR SCHISTOSOMIASIS WITH FRACTION ANTIGEN OF SOLUBLE EGG ANTIGEN OF SCHISTOSOMA JAPONICUM
Yinchang ZHU ; Wanquan HUA ; Yunjuan LIU ; Wei HE ; Yongliang XU ;
Chinese Journal of Schistosomiasis Control 1992;0(06):-
This study reported the primary application of FA-ELISA from 107-121kDa fration antibody of Schistosoma Japonicum for detection of the short-term antibody in patients with schistosomiasis. The result showed that this method provided high sensitivity (with positive rate of 93. 33% with 30 cases of schistosomiasis) and good specificity (no false postive in 60 health objects). When one group of schistosome patients were examined with FA -ELISA and with the routine SEA-ELISA before chemotherapy and at 8 months,1 year and 1. 5 year after treatment,it showed good property for evaluation of chemotherapy efficacy with FA -ELISA,which was much better than the routine method.
6.Preparation of niclosamide ethanolamine nano-suspension and its molluscicidal effect
Liu JIANG ; Shufeng LI ; Xinsong LI ; Jianrong DAI ; Yinchang ZHU
Chinese Journal of Schistosomiasis Control 1989;0(02):-
Objective To prepare a novel nano-suspension of niclosamide ethanolamine and evaluate its molluscicidal effect. Methods Niclosamide ethanolamine and stabilizing agent—polyvinylpyrrolidone (PVP) were dissolved in dimethyl sulfoxide. After the solution was added into water under fast stirring, niclosamide ethanolamine was quickly precipitated to form nanoparticles and nano-suspension was obtained. The weight ratio of PVP to niclosamide ethanolamine, concentration, temperature, stirring speed on the size and distribution of the nanoparticles were investigated. The molluscicidal effect of niclosamide ethanolamine nano-suspension was measured by immersion and spray methods in the laboratory and field. Results When the weight ratio of PVP to niclosamide ethanolamine was from 1∶2 to 1∶3, the nanoparticles of the niclosamide ethanolamine had diameters about 100 nm and the nano-suspension was stable without agglomerating for more than 1 month; as the speed of the stirring increased, the nanoparticles prepared became smaller and more stable. LC50 of the nano-suspension was 0.0544 mg/L but the LC50 of wettable powder of niclosamide ethanolamine salt (WPN) was 0.1250 mg/L. In the field immersion and spray tests, the concentration of nano-suspension as only 1/5 of active content of WPN achieved the same molluscicidal effect with WPN. Conclusions The nano-suspension has higher molluscicidal effect than WPN and the novel formulation of niclosamide has more advantages than WPN, it is useful for snail control in the field.
7.Fusion Expression and Antigenicity Analysis of MiracidialAntigen from Eggs of Schistosoma japonicum
Jianfa LIU ; Chuanxin YU ; Yinchang ZHU ; Xuren YIN ; Yongliang XU
Chinese Journal of Parasitology and Parasitic Diseases 1987;0(03):-
Objectives To express the miracidial antigen from eggs of Schistosoma japonicum (Chinese mainland strain) (SjMP10), and investigate the role of the miracidial antigen during the hepatic granuloma formation of schistosomiasis. Methods A pair of specific primers was designed and synthesized according to the nucleotide sequence of the open reading frame of the miracidial antigen gene. The open reading frame of the miracidial antigen gene was amplified, digested by restrictive enzyme(BamHI, SalI), and cloned directly into the expression plasmid pGEX-4T-3 to construct the recombinant plasmid. The recombinant plasmids were transformed into E. coli BL21(DE3), and induced by IPTG to express the fusion protein of GST-SjMP10. The expressed fusion protein was purified by electric elution method, and its antigenicity was examined by Western blotting and lymphocyte proliferation test. Results The gene of miracidial antigen was cloned into the expression plasmid pGEX-4T-3. After induced by IPTG, the recombinant expressed a fusion protein of GST-SjMP10, with a molecular weight of 39 000 approximately. The purified fusion protein showed proper antigenicity that could be recognized by the sera of rabbits heavily infected by Schistosoma japonicum and could stimulate the proliferation of splenic lymphocytes of infected BALB/c mice. Conclusion The miracidial antigen from eggs of Schistosoma japonicum was expressed successfully.

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