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.

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.

Objective:To explore the feasibility and safety of the combined liver and kidney procurement technique with preservation of the donor diaphragm.Methods:A retrospective study was conducted on the clinical data of 135 donors with pulmonary infection who underwent combined liver and kidney procurement and their corresponding 370 recipients in the Department of Transplantation, Guangxi Zhuang Autonomous Region People's Hospital from January 2021 to August 2023. According to whether the donor diaphragm was resected during procurement, the donors were divided into diaphragm preservation group (67 cases) and diaphragm resection group (68 cases). The t-test and chi-square test were used to compare the baseline characteristics of the donors, donor procurement time, surgical injury to organs, donor-derived infection (DDI), delayed graft function (DGF), primary non-function (PNF), and perioperative death between the two groups.Results:There were no statistically significant differences in age, sex, body mass index, number of organs procured, number of organs transplanted, number of organs discarded, or positive rate of sputum cultures for different strains between the two groups (all P>0.05). The donor procurement time was (46.70±12.61) min in the diaphragm preservation group and (45.79±12.78) min in the diaphragm resection group, with no statistically significant difference ( P=0.679). No surgical injuries to other abdominal organs (such as intestines or, in the diaphragm resection group, the lungs) occurred during procurement. After transplantation, the incidence of delayed graft function in kidney recipients was 7.32% (9/123) in the diaphragm preservation group and 11.67% (14/120) in the diaphragm resection group, with no statistically significant difference between the two groups ( P=0.279). The incidence of DDI was 0 in the diaphragm preservation group and 7.07% (13/184) in the diaphragm resection group, showing a statistically significant difference ( P<0.001). No cases of primary non-function or perioperative death occurred in either group. Conclusion:Compared with the conventional method, the combined liver and kidney procurement technique that preserves the donor diaphragm does not significantly increase operative time, organ injury, delayed graft function, primary non-function, or perioperative mortality. It significantly reduces the incidence of donor-derived infections and is worthy of clinical promotion and application.

To summarize and analyze the clinical data of one case of kidney transplantation in an HIV-positive child with end-stage renal disease (ESRD) in the Department of Transplantation, the People's Hospital of Guangxi Zhuang Autonomous Region, and to explore the safety and efficacy of kidney transplantation in HIV-positive children with ESRD. This pediatric recipient was found to be HIV-positive at birth and underwent kidney transplantation due to ESRD, with good postoperative recovery. During the 2.5-year follow-up, no rejection or rebound in HIV RNA levels was observed. The function of the transplanted kidney was good, and the quality of life was comparable to that of healthy individuals. It suggests that kidney transplantation in HIV-positive children with ESRD is safe and effective under adequate preoperative preparation and close postoperative follow-up.

Objective:To investigate the efficacy of using a single Kocher-Langenbeck approach to improve anterior column screw fixation for the treatment of transverse + posterior wall acetabular fractures.Method:A retrospective analysis was conducted of the data of 21 patients who had been treated with a single Kocher-Langenbeck approach to improve anterior column screw fixation for transverse + posterior wall acetabular fractures at Department of Orthopaedics, Weifang People's Hospital from May 2021 to May 2023. There were 11 males and 10 females with an age of (51.3±15.5) years. The time from injury to surgery was (10.4±3.6) days. The anterior column screw fixation was improved as follows: screws were implanted 1 to 2 cm in front of the apex of the great notch of the external iliac plate of the pelvis to penetrate out at the upper branch root of the pubic ramus, with the whole screw fully located within the bony channel. Such indexes were recorded as surgical time, intraoperative blood loss, intraoperative fluoroscopy frequency for improved placement of anterior column screws, fracture healing time, incidence of complications, and fracture reduction and hip joint function at the last follow-up.Results:For this cohort, surgical time was (120.9±40.7) minutes, intraoperative blood loss (330.2±65.9) mL, and intraoperative fluoroscopy frequency for improved placement of anterior column screws (6.2±2.3) times. The 21 patients were followed up for (21.5±5.9) months. All fractures achieved bony union after (3.2±1.1) months. Incision fat liquefaction occurred in 1 patient after surgery and symptoms of sciatic nerve injury were observed in 2 patients. Follow-ups observed no such complications as loosening or breakage of internal fixators. According to the Matta scoring criteria, the quality of fracture reduction at the last follow-up was evaluated as anatomical reduction in 15 cases, as satisfactory reduction in 4 cases, as acceptable reduction in 2 cases, giving a satisfaction rate of 90.5% (19/21). According to the improved Merle d'Aubigné & Poster scoring criteria, hip function was evaluated as excellent in 16 cases, as good in 2 cases, and as fair in 3 cases, giving an excellent and good rate of 85.7% (18/21).Conclusion:It is effective to use a single Kocher-Langenbeck approach to improve anterior column screw fixation for the treatment of transverse + posterior wall acetabular fractures, showing advantages of reduced surgical time and intraoperative bleeding.

Objective To explore the application effect of bedside critical ultrasound in volume management of acute kidney injury(AKI)donors.Methods Clinical data of 56 AKI donors and 106 recipients from the Transplantation Center of People's Hospital of Guangxi Zhuang Autonomous Region from October 1,2020 to May 31,2022 were collected.They were divided into the critical ultrasound group(34 donors,66 recipients)and the traditional central venous pressure(CVP)group(22 donors,40 recipients)according to the volume management methods.The AKI stage and recovery time,renal function indicators(serum creatinine(Scr),cystatin C,estimated glomerular filtration rate),donor Remuzzi score,cold ischemia time,biventricular inotrope usage rate and time,delayed graft function(DGF)incidence and recovery time,and renal function indicators at 6 and 12 months after surgery were compared and analyzed between the two groups.Results There were no statistically significant differences in gender,age,body weight,AKI stage,pre-acquisition renal function indicators,biventricular inotrope usage rate,renal function indicators at 6 and 12 months after surgery,DGF recovery time,donor Remuzzi score and cold ischemia time of the donors and recipients between two groups(all P>0.05).The AKI recovery time,continuous renal replacement therapy rate and biventricular inotrope usage time of donors in the critical ultrasound group were shorter or lower than those in the traditional CVP group(all P<0.05).The incidence of DGF in recipients of the critical ultrasound group was lower than that of the traditional CVP group(P<0.05).Subgroup analysis showed that there was no statistically significant difference in Scr at 6 and 12 months after surgery in recipients of the critical ultrasound group(P>0.05),while the Scr at 12 months after surgery was higher than that at 6 months in recipients of the traditional CVP group(P<0.05).Conclusions AKI kidneys may be used for kidney transplantation after active maintenance.Bedside critical ultrasound has unique advantages in volume management of AKI donors and may improve the function of AKI kidneys to a certain extent.

Objective To explore the application effect of bedside critical ultrasound in volume management of acute kidney injury(AKI)donors.Methods Clinical data of 56 AKI donors and 106 recipients from the Transplantation Center of People's Hospital of Guangxi Zhuang Autonomous Region from October 1,2020 to May 31,2022 were collected.They were divided into the critical ultrasound group(34 donors,66 recipients)and the traditional central venous pressure(CVP)group(22 donors,40 recipients)according to the volume management methods.The AKI stage and recovery time,renal function indicators(serum creatinine(Scr),cystatin C,estimated glomerular filtration rate),donor Remuzzi score,cold ischemia time,biventricular inotrope usage rate and time,delayed graft function(DGF)incidence and recovery time,and renal function indicators at 6 and 12 months after surgery were compared and analyzed between the two groups.Results There were no statistically significant differences in gender,age,body weight,AKI stage,pre-acquisition renal function indicators,biventricular inotrope usage rate,renal function indicators at 6 and 12 months after surgery,DGF recovery time,donor Remuzzi score and cold ischemia time of the donors and recipients between two groups(all P>0.05).The AKI recovery time,continuous renal replacement therapy rate and biventricular inotrope usage time of donors in the critical ultrasound group were shorter or lower than those in the traditional CVP group(all P<0.05).The incidence of DGF in recipients of the critical ultrasound group was lower than that of the traditional CVP group(P<0.05).Subgroup analysis showed that there was no statistically significant difference in Scr at 6 and 12 months after surgery in recipients of the critical ultrasound group(P>0.05),while the Scr at 12 months after surgery was higher than that at 6 months in recipients of the traditional CVP group(P<0.05).Conclusions AKI kidneys may be used for kidney transplantation after active maintenance.Bedside critical ultrasound has unique advantages in volume management of AKI donors and may improve the function of AKI kidneys to a certain extent.

Objective:To investigate the efficacy of using a single Kocher-Langenbeck approach to improve anterior column screw fixation for the treatment of transverse + posterior wall acetabular fractures.Method:A retrospective analysis was conducted of the data of 21 patients who had been treated with a single Kocher-Langenbeck approach to improve anterior column screw fixation for transverse + posterior wall acetabular fractures at Department of Orthopaedics, Weifang People's Hospital from May 2021 to May 2023. There were 11 males and 10 females with an age of (51.3±15.5) years. The time from injury to surgery was (10.4±3.6) days. The anterior column screw fixation was improved as follows: screws were implanted 1 to 2 cm in front of the apex of the great notch of the external iliac plate of the pelvis to penetrate out at the upper branch root of the pubic ramus, with the whole screw fully located within the bony channel. Such indexes were recorded as surgical time, intraoperative blood loss, intraoperative fluoroscopy frequency for improved placement of anterior column screws, fracture healing time, incidence of complications, and fracture reduction and hip joint function at the last follow-up.Results:For this cohort, surgical time was (120.9±40.7) minutes, intraoperative blood loss (330.2±65.9) mL, and intraoperative fluoroscopy frequency for improved placement of anterior column screws (6.2±2.3) times. The 21 patients were followed up for (21.5±5.9) months. All fractures achieved bony union after (3.2±1.1) months. Incision fat liquefaction occurred in 1 patient after surgery and symptoms of sciatic nerve injury were observed in 2 patients. Follow-ups observed no such complications as loosening or breakage of internal fixators. According to the Matta scoring criteria, the quality of fracture reduction at the last follow-up was evaluated as anatomical reduction in 15 cases, as satisfactory reduction in 4 cases, as acceptable reduction in 2 cases, giving a satisfaction rate of 90.5% (19/21). According to the improved Merle d'Aubigné & Poster scoring criteria, hip function was evaluated as excellent in 16 cases, as good in 2 cases, and as fair in 3 cases, giving an excellent and good rate of 85.7% (18/21).Conclusion:It is effective to use a single Kocher-Langenbeck approach to improve anterior column screw fixation for the treatment of transverse + posterior wall acetabular fractures, showing advantages of reduced surgical time and intraoperative bleeding.

Objective:To explore the feasibility and safety of the combined liver and kidney procurement technique with preservation of the donor diaphragm.Methods:A retrospective study was conducted on the clinical data of 135 donors with pulmonary infection who underwent combined liver and kidney procurement and their corresponding 370 recipients in the Department of Transplantation, Guangxi Zhuang Autonomous Region People's Hospital from January 2021 to August 2023. According to whether the donor diaphragm was resected during procurement, the donors were divided into diaphragm preservation group (67 cases) and diaphragm resection group (68 cases). The t-test and chi-square test were used to compare the baseline characteristics of the donors, donor procurement time, surgical injury to organs, donor-derived infection (DDI), delayed graft function (DGF), primary non-function (PNF), and perioperative death between the two groups.Results:There were no statistically significant differences in age, sex, body mass index, number of organs procured, number of organs transplanted, number of organs discarded, or positive rate of sputum cultures for different strains between the two groups (all P>0.05). The donor procurement time was (46.70±12.61) min in the diaphragm preservation group and (45.79±12.78) min in the diaphragm resection group, with no statistically significant difference ( P=0.679). No surgical injuries to other abdominal organs (such as intestines or, in the diaphragm resection group, the lungs) occurred during procurement. After transplantation, the incidence of delayed graft function in kidney recipients was 7.32% (9/123) in the diaphragm preservation group and 11.67% (14/120) in the diaphragm resection group, with no statistically significant difference between the two groups ( P=0.279). The incidence of DDI was 0 in the diaphragm preservation group and 7.07% (13/184) in the diaphragm resection group, showing a statistically significant difference ( P<0.001). No cases of primary non-function or perioperative death occurred in either group. Conclusion:Compared with the conventional method, the combined liver and kidney procurement technique that preserves the donor diaphragm does not significantly increase operative time, organ injury, delayed graft function, primary non-function, or perioperative mortality. It significantly reduces the incidence of donor-derived infections and is worthy of clinical promotion and application.

To summarize and analyze the clinical data of one case of kidney transplantation in an HIV-positive child with end-stage renal disease (ESRD) in the Department of Transplantation, the People's Hospital of Guangxi Zhuang Autonomous Region, and to explore the safety and efficacy of kidney transplantation in HIV-positive children with ESRD. This pediatric recipient was found to be HIV-positive at birth and underwent kidney transplantation due to ESRD, with good postoperative recovery. During the 2.5-year follow-up, no rejection or rebound in HIV RNA levels was observed. The function of the transplanted kidney was good, and the quality of life was comparable to that of healthy individuals. It suggests that kidney transplantation in HIV-positive children with ESRD is safe and effective under adequate preoperative preparation and close postoperative follow-up.