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 risk factors of acute Kemmochi type V anterior talofibular ligament (ATFL) injury in X-ray negative children and their predictive efficacy .Methods:A retrospective cohort study was conducted to analyze the clinical data of 92 children with X-ray negative ATFL injury, who were treated at the outpatient department of Jinan Children′s Hospital from June 2023 to March 2025, including 55 boys and 37 girls, aged 5-14 years [8.8(7.0, 11.0)years]. The cause of injury was low-energy ankle sprain and X-ray examination showed no fracture, ie, X-ray negative. According to the Kemmochi classification for ATFL injury, the injury was classified as type V (Kemmochi type V group) in 42 patients and type I-IV (non-Kemmochi type V group) in 50. Gender, age, side of injury, time from injury to first visit, physical examination at the first visit [positive result of ankle inversion test, weight-bearing ability assessment, visual analogue score (VAS)], X-ray examination at the first visit (presence of os subfibulare), and musculoskeletal ultrasound examination at the first visit (swelling degree of ATFL, ankle joint effusion, enhanced blood flow signal of ATFL) were recorded in both groups. Univariate analysis and binary Logistic regression analysis were used to evaluate and determine the independent risk factors for X-ray negative Kemmochi type V ATFL injury in children. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the predictive efficacy of each independent risk factor for Kemmochi type V ATFL injury. Results:Univariate analysis showed significant differences between the two groups in age, VAS, ATFL swelling degree, and ankle joint effusion ( P<0.05) but no significant differences in gender, side of injury, time from injury to the first visit, positive result of ankle inversion test, weight-bearing ability assessment, presence of os subfibulare or enhanced blood flow of ATFL ( P>0.05). Binary Logistic regression analysis indicated that age ( OR=0.79, 95% CI 0.65, 0.97, P<0.05) and ATFL swelling degree ( OR=6.97, 95% CI 1.38, 35.32, P<0.05) were significantly correlated with Kemmochi type V ATFL injury in X-ray negative children. ROC curve analysis showed that the AUC for age and ATFL swelling degree were 0.65(95% CI 0.54, 0.75) and 0.78(95% CI 0.68, 0.86) and the AUC for age combined with ATFL swelling degree was 0.83(95% CI 0.74, 0.90). The optimal threshold values of age and ATFL swelling degree were 9.3 years and 1.0 mm. Conclusions:Age and ATFL swelling degree are independent risk factors for Kemmochi type V ATFL injury in X-ray negative children. Both age and ATFL swelling degree have relatively high independent predictive efficacy, and the combined predictive efficacy of the two is even higher.

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 risk factors of acute Kemmochi type V anterior talofibular ligament (ATFL) injury in X-ray negative children and their predictive efficacy .Methods:A retrospective cohort study was conducted to analyze the clinical data of 92 children with X-ray negative ATFL injury, who were treated at the outpatient department of Jinan Children′s Hospital from June 2023 to March 2025, including 55 boys and 37 girls, aged 5-14 years [8.8(7.0, 11.0)years]. The cause of injury was low-energy ankle sprain and X-ray examination showed no fracture, ie, X-ray negative. According to the Kemmochi classification for ATFL injury, the injury was classified as type V (Kemmochi type V group) in 42 patients and type I-IV (non-Kemmochi type V group) in 50. Gender, age, side of injury, time from injury to first visit, physical examination at the first visit [positive result of ankle inversion test, weight-bearing ability assessment, visual analogue score (VAS)], X-ray examination at the first visit (presence of os subfibulare), and musculoskeletal ultrasound examination at the first visit (swelling degree of ATFL, ankle joint effusion, enhanced blood flow signal of ATFL) were recorded in both groups. Univariate analysis and binary Logistic regression analysis were used to evaluate and determine the independent risk factors for X-ray negative Kemmochi type V ATFL injury in children. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the predictive efficacy of each independent risk factor for Kemmochi type V ATFL injury. Results:Univariate analysis showed significant differences between the two groups in age, VAS, ATFL swelling degree, and ankle joint effusion ( P<0.05) but no significant differences in gender, side of injury, time from injury to the first visit, positive result of ankle inversion test, weight-bearing ability assessment, presence of os subfibulare or enhanced blood flow of ATFL ( P>0.05). Binary Logistic regression analysis indicated that age ( OR=0.79, 95% CI 0.65, 0.97, P<0.05) and ATFL swelling degree ( OR=6.97, 95% CI 1.38, 35.32, P<0.05) were significantly correlated with Kemmochi type V ATFL injury in X-ray negative children. ROC curve analysis showed that the AUC for age and ATFL swelling degree were 0.65(95% CI 0.54, 0.75) and 0.78(95% CI 0.68, 0.86) and the AUC for age combined with ATFL swelling degree was 0.83(95% CI 0.74, 0.90). The optimal threshold values of age and ATFL swelling degree were 9.3 years and 1.0 mm. Conclusions:Age and ATFL swelling degree are independent risk factors for Kemmochi type V ATFL injury in X-ray negative children. Both age and ATFL swelling degree have relatively high independent predictive efficacy, and the combined predictive efficacy of the two is even higher.

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 understand the epidemiological and etiological characteristics of hand-foot-mouth disease (HFMD) in the Nanshan District of Shenzhen City from 2019 to 2022 and to provide a scientific basis for HFMD prevention in the area.Methods:Epidemiological data on HFMD in Shenzhen Nanshan District from 2019 to 2022 in the China Information System for Disease Control and Prevention were analyzed using descriptive research methods.Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to analyze the etiology characteristics of clinical specimens from HFMD patients. The VP1 gene of the dominant pathogen coxsackievirus A6 (CV-A6) was amplified and sequenced. SepMan Pro of DNASTAR software was used for sequence assembly and MegAlign was used for nucleotide homology analysis.Results:A total of 13 195 HFMD cases were reported in Shenzhen Nanshan District from 2019 to 2022, with an average annual incidence rate of 186.18/100, 000. Summer and autumn are the main onset seasons and children under 7 years old were the main population, accounting for 93.1%. The male-to-female ratio is 1.44∶1. A total of 451 clinical HFMD specimens were detected in the laboratory, including 403 positive (87.36%) and 48 negative (10.64%). The main pathogens were CV-A6 (63.03%), coxsackievirus A16 (CV-A16) (27.79%), coxsackievirus A4 (CV-A4) (4.71%), coxsackievirus A10 (CV-A10) (1.99%), Echovirus 11 (Echo-11) (0.25%), and uncertain type accounted for 2.23%, with no detection for enterovirus71 (EV71) type. The nucleotide homology of the 13 CV-A6 strains ranged from 94.0%?99.6%, and the nucleotide homology with the prototype strain Gdula ranged 84.1%?85.8%. The results of phylogenetic tree showed that all 13 CV-A6 strains in Nanshan District were of the D3a genotype.Conclusions:FHFMD in Nanshan District of Shenzhen City in 2019-2022 shows obvious differences in population and time distribution. Therefore, it is necessary to strengthen publicity and education on HFMD prevention and control in the summer and fall seasons and among key populations. CV-A6 and CV-A16 are the dominant strains of HFMD in Nanshan District, Shenzhen in recent years, so the monitoring of the dominant strains should be improved.

Objective:To investigate the clinical features of the initial phase of acute osteomyelitis in children with skin and soft tissue infection as the main sign.Methods:The clinical data of 154 children with skin and soft tissue infections as the main sign from July 2017 to February 2023 were retrospectively analyzed. According to MRI, 48 children with no signs of osteomyelitis and only simple skin and soft tissue infection were included in the non-osteomyelitis group, including 28 boys and 20 girls, aged 38.50 (12.00, 93.00) months; 106 children with acute osteomyelitis with skin and soft tissue infection as the main sign were included in the osteomyelitis group, including 65 boys and 41 girls, aged 49.50 (17.50, 87.00) months. The disease course, maximum body temperature at onset, inflammatory indicators (including white blood cell count, neutrophil count, C-reactive protein, erythrocyte sedimentation rate) examined within 24 h after admission were compared between the two groups, and receiver operating characteristic (ROC) curve was used to evaluate the efficacy of each index in diagnosing osteomyelitis.Results:The white blood cell counts in the non-osteomyelitis group and osteomyelitis group were 13.72 (10.19, 19.19) ×10 9 /L and 14.74 (10.63, 18.67) ×10 9 /L, and the neutrophil counts were 7.79 (5.62, 11.91) ×10 9 /L and 9.58 (5.77, 13.67) ×10 9 /L, the difference was not statistically significant ( Z=-0.68, P=0.495; Z=-1.24, P=0.216). The course of disease in the non-osteomyelitis group and osteomyelitis group was 5.00 (3.00, 7.00) d and 5.50 (4.00, 9.00) d ( Z=-2.03, P=0.042), and the maximum body temperature at the onset of the disease was 38.50 (36.65, 39.00) ℃ and 39.00 (38.50, 40.00) ℃ ( Z=-3.72, P<0.001), C-reactive protein was 23.26 (8.16, 47.67) mg/L and 69.27 (26.28, 111.03) mg/L ( Z=-4.52, P<0.001), erythrocyte sedimentation rate was 35.00 (24.25, 53.00) mm/1 h and 61.00 (43.00, 78.00) mm/1 h ( Z=-5.06, P<0.001), the differences were statistically significant. The proportion of patients with increased C-reactive protein was 70.8% (34/48) and 92.5% (98/106) in non-osteomyelitis group and osteomyelitis group, the proportion of patients with increased erythrocyte precipitation rate was 81.3% (39/48) and 100% (106/106), and the proportion of patients with fever was 66.7% (32/48) and 100% (106/106), respectively, the difference was statistically significant (χ 2=12.61, P<0.001; χ 2=21.11, P<0.001; χ 2=39.43, P<0.001). The sensitivity, specificity and area under the curve of osteomyelitis were 84.0%, 33.3% and 0.602, respectively. The maximum body temperature at onset was 99.1%, 35.4% and 0.687, and the C-reactive protein was 57.6%, 85.4% and 0.728, respectively. Erythrocyte sedimentation rates were 84.0%, 56.3% and 0.755, respectively. Multivariate logistic regression analysis indicated that the maximum body temperature was >37.6 ℃ [ OR=22.54, 95% CI (2.66, 190.81)] and C-reactive protein was >54.59 mg /L [ OR=4.23, 95% CI (1.63, 11.01)] was an independent risk factor for predicting osteomyelitis with skin and soft tissue infection as the main sign. Conclusion:Compared to simple skin and soft tissue infections, children with osteomyelitis had a higher proportion of fever, elevated C-reactive protein, and elevated erythrocyte sedimentation rate, a longer duration of illness, and higher elevations in temperature, C-reactive protein, and erythrocyte sedimentation rate. Length of onset, maximum body temperature at onset, C-reactive protein and erythrocyte sedimentation rate had certain diagnostic efficacy in determining the tendency of skin soft tissue infection to osteomyelitis. Maximum body temperature >37.6 ℃ and C-reactive protein >54.59 mg/L may independently predict the possibility of skin soft tissue infection as osteomyelitis, and prompt Magnetic Resonance Imaging is recommended for early diagnosis and treatment in such children.

Scientific research is important for the improvement of the health-care techniques,and is certainly important for the health of women and children of the whole society.With the development of medical science,research ability of maternal and child healthcare professionals is deemed essential.And the evaluation of their research ability,stimulation,and creativity have been important topics to address.Here we introduce an evaluation system for research capacity of maternal and child healthcare professionals established in our hospital,which is the fruit of constant exploration and practice for several years.It is proved to be practical,simple and feasible.The establishment methods,practices and experiences of the evaluation system are presented in this paper.

ObjectiveTo investigate genetic polymorphism of 3 STR loci in Bouyei ethnic group in Guizhou.Methods The DNAs of 101 healthy unrelated Bouyei individuals in Guizhou were extracted using chelex-100 method and were multiplex amplificated by PCR technique and the denatured PAGE was used, the PCR product was typied using silver stain method. The data was statistically analysed by modified-powerstat software package. Results A total of 21 alleles and 50 genotypes were observed in the 3 loci and the distributions of these genotypes were consistent with the law of Hardy-Weinberg equilibrium. The heterozygosity(H) of CSF1PO, TPOX and TH01 loci were 0.7287,0.5423 and 0.6904; the polymorphism information content(PIC) were 0.6805,0.4479 and 0.6426; the discrimination power(DP) were 0.8782,0.7361 and 0.8563 and the probabilities of paternity exclusion (PPE)were 0.6148、0.3643 and 0.5737 respectively. Conclution CSF1PO and THOX are highly genetic polymolphism, which is valuable for population genetic research and forensic individual identification. The distrbution of gene frequencies and their area of ethnic groups have parallel relation.