1.Perioperative immune dynamics and clinical outcomes in patients undergoing on-pump cardiac surgery
Zhiyuan CHENG ; Xinyi LIAO ; Juan WU ; Ping YANG ; Tingting WANG ; Qinjuan WU ; Wentong MENG ; Zongcheng TANG ; Jiayi SUN ; Jia TAN ; Jing LIN ; Dan LUO ; Hao WANG ; Chaonan LIU ; Jiyue XIONG ; Liqin LING ; Jing ZHOU ; Lei DU
Chinese Journal of Blood Transfusion 2026;39(1):31-43
Objective: To characterize perioperative dynamic changes in immune-cell phenotypes and inflammatory cytokines in patients undergoing CPB (cardiopulmonary bypass) cardiac surgery, and to explore their associations with postoperative outcomes. Methods: In this prospective cohort study, 120 adult patients who underwent elective cardiac surgery under CPB at West China Hospital from May 2022 to March 2023 were enrolled. Perioperative immune-cell phenotypes and concentrations of 40 inflammation-related cytokines were measured. The primary outcomes were the sequential organ failure assessment (SOFA) score at 24 h after surgery and ΔSOFA (the peak SOFA score within 48 h after surgery minus the preoperative SOFA score). Secondary outcomes included major adverse cardiovascular events (MACE), acute kidney injury (AKI), respiratory failure, severe liver injury, and infection. Results: The mean age of enrolled patients was 57±10 years. Of these, 52% (62/120) were male and 90% (108/120) underwent valve surgery. During the rewarming to the end of CPB, neutrophil counts rapidly increased (7.39×10
/L vs preoperative 3.07×10
/L, P<0.001), with significant upregulation of CD11b (7.30×10
/L vs preoperative 3.05×10
/L, P<0.001) and CD54 (7.15×10
/L vs preoperative 2.99×10
/L, P<0.001). Lymphocyte counts increased at the end of CPB (1.75×10
/L vs preoperative 1.12×10
/L, P<0.001) but decreased significantly at 24 h after surgery (0.59×10
/L vs preoperative 1.12×10
/L, P<0.001). Plasma analysis showed that multiple pro-inflammatory cytokines increased during CPB and remained elevated up to 24 h after surgery; five chemokines and the anti-inflammatory cytokine IL-10 peaked at the end of CPB. The SOFA score increased from 1 (1, 2) preoperatively to 7 (5, 10) at 24 h after surgery, with a ΔSOFA of 6 (4, 8). Within 30 days after surgery, 48 patients (40.0%) developed AKI, 17 (14.2%) developed infection, 4 (3.3%) developed severe liver injury, 3 (2.5%) developed respiratory failure, and 3 (2.5%) experienced MACE. During the 2-year follow-up, 8 patients (6.7%) experienced MACE and 5 (4.2%) died. Conclusion: Multi-organ dysfunction is common after cardiac surgery under CPB (median ΔSOFA, 6), accompanied by perioperative activation of multiple immune-cell subsets and upregulation of pro-inflammatory, anti-inflammatory, and chemotactic mediators. This study provides data-driven evidence and research clues for further investigation of the associations between CPB-related immune perturbations and postoperative organ dysfunction and clinical outcomes.
2.Active monitoring of ceftazidime-avibactam sodium-related adverse reactions of blood system and influencing factors
Ru WANG ; Mengqian QIAO ; Wanyue CHENG ; Man ZHU ; Hong YIN
Chinese Journal of Nosocomiology 2025;35(10):1557-1562
OBJECTIVE To acquire the real-world incidence of ceftazidime-avibactam sodium(CAZ)-related ad-verse reactions of blood system among a large sample of drug medication patients based on the active monitoring system so as to provide reference for safe clinical use of drugs.METHOD With the help of'Adverse Drug Event Active Surveillance and Assessment System-Ⅱ'(ADE-ASAS-Ⅱ),the use of CAZ of the patients who were hospi-talized in Chinese PLA General Hospital from Jan.1,2020 to Dec.31,2023 were retrospectively and automatical-ly monitored,the patients who were alarmed by system were evaluated by two persons,the incidence rates of CAZ-related thrombocytopenia,hemoglobin decreased and leucopenia were calculated,and the related influencing factors were analyzed.RESULTS Among the 278 case-times(191 cases)of patients who were treated with drugs and were enrolled in the study,there were 3(1.08%)case-times of thrombocytopenia,8(2.88%)case-times of hemoglobin decreased and 19(6.83%)case-times of leucopenia;the total incidence of adverse reactions of blood system was 10.79%.Logistic regression analysis showed that age and duration of drug administration were the in-fluencing factors for the CAZ-related adverse reactions of blood system.CONCLUSIONS It is common for the CAZ-related adverse reactions of blood system.The middle-aged and elderly patients who take drug therapy for a long time period are more likely to have the blood system-related adverse reactions.It is necessary to focus on the monitoring of renal function of the patients and adjust the dosage of administration in a timely manner so as to re-duce the incidence of adverse reactions of the blood system.
3.Analysis of Clinical Features and Multi-Slice Spiral CT Image Features of Acute Appendicitis in Soldiers Who Have Been Living in Plateau for A Long Time
Li-na YUE ; Juan-qin NIU ; Gang CHEN ; Man-ping CHENG ; Ning-xia MU ; Jia FAN ; Kang LIU ; Yu-lan NIU ; Ya-ping HE ; Zhong-hua LI
Progress in Modern Biomedicine 2025;25(11):1869-1878
Objective:To investigate the clinical features and multi-slice spiral computed tomography(CT)imaging features of acute appendicitis in soldiers who have been living in plateau for a long time.Methods:The clinical features and imaging data of 56 cases of acute appendicitis in soldiers who have been living in plateau for a long time confirmed by surgery from February 2022 to August 2024 were retrospectively analyzed.Results:In 56 cases with acute appendicitis in soldiers who have been living in plateau for a long time,the appendectomy position results showed:anterior ileum 4 cases(7.14%),lower ileum 10 cases(17.86%),posterior cecum 16 cases(28.57%),lower cecum 9 cases(16.07%),lateral cecum 2 cases(3.58%),posterior ileum 6 cases(10.71%),high(subhepatic)9 cases(16.07%),and left lower abdominal 0 cases,retroperitoneal appendicitis 0 cases,which was suggested that the anatomical position variation of appendicitis in soldiers with acute appendicitis who have been living at high altitude for a long time was relatively large.The direct manifestations of multi-slice spiral CT showed:appendectomy enlarged diameter>6 mm in 49 cases(87.50%),appendicular wall thickening>2 mm in 42 cases(75.00%),ppendiceal dilation lumen and effusion in 29 cases(51.79%),appendix indistinctness in 3 cases(5.36%),lppendix fecalith:27 cases(48.21%),gas in the appendix in 16 cases(28.57%).Indirect findings of multi-slice spiral CT showed that,periappendiceal exudation with shadow in 32 cases(57.14%),appendiceal cellulitis with peripheral abscess in 9 cases(16.07%),peritonitis and ascites in 13 cases(23.21%),ileocecal intestinal wall thickening in 22 cases(39.29%),mesenteric lymph node enlargement in 16 cases(28.57%),reflexive intestinal stasis in ileocecal region was observed in 19 cases(33.93%).Conclusion:In the officers and soldiers with acute appendicitis who lived at high altitude for a long time,multi-slice spiral CT showed the direct manifestations of appendiceal thickening,tube wall thickening,lumen dilatation,fluid accumulation,etc.,and the indirect manifestations were periappendiceal exudation with shadow,appendiceal cellulitis with peripheral abscess,ileocecal intestinal wall thickening,reflexes of small intestine and mesenteric lymph node enlargement.Multi-slice spiral CT has the advantages of clear and intuitive,high safety,high resolution and simple operation in the diagnosis of acute appendicitis.
4.Modified Chevron osteotomy for moderate and severe hallux valgus deformity with enlarged distal metatarsal articular angle
Zizhang LIU ; Yiheng CHENG ; Tong LIU ; Yu YUAN ; Yu SONG ; Ruidong ZHANG ; Yuanpeng MAN ; Wenqing QU
Chinese Journal of Plastic Surgery 2025;41(7):682-691
Objective:To evaluate the radiological and functional outcomes of moderate to severe hallux valgus patients with enlarged distal metatarsal articular angle (DMAA) underwent modified Chevron osteotomy.Methods:The clinical data of patients with moderate and severe hallux valgus with increased distal metatarsal joint angle who accepted surgery operation in the Department of Foot and Ankle Surgery of Yantaishan Hospital from October 2020 to December 2022 were retrospectively analyzed. All patients underwent modified Chevron osteotomy. Taking the proximal end of the metatarsal head centre as the osteotomy apex, the vertical arm osteotomy line in the sagittal plane made an angle of ≤80° with the metatarsal stem, the horizontal plane was inclined to the lateral distal end of the metatarsal head by about 10°, and the sagittal plane metatarsal arm osteotomy line made an angle of ≥90° with the vertical arm osteotomy line; at the proximal osteotomy surface, another cuneiform bone with its base on the medial and its apex on the lateral was resected. The deformity correction was insufficient and Akin osteotomy was performed in combination. Weil osteotomy was performed in combination with metatarsalgia. Radiological assessment including the hallux valgus angle (HVA), intermetatarsal angle (IMA), DMAA, the joint congruity angle (JCA), forefoot bone width and soft tissue width was performed preoperatively and at last follow-up postoperatively. American Orthopedic Foot and Ankle Society/hallux metatarsophalangeal-interphalangeal scale (AOFAS/HMIS) was used for clinical and functional evaluation, total score from 0 to 100, with higher scores indicating better function.Visual analogue scale (VAS) was used for pain valuation, total score from 0 to 10, with higher scores indicating more pain. A questionnaire survey on patient satisfaction was conducted at the last follow-up. Shapiro-Wilk test was used for normal distribution test, and measurement data following normal distribution were represented as Mean±SD. Paired t-test was used for comparison before and after operation. Other indicators conformed to non-normal distribution were denoted by M( Q1, Q3) and were tested by Wilcoxon signed-rank test. P<0.05 was considered statistically significant. Results:Fifty-two feet of 48 patients (5 males, 43 females; mean age (52.4±14.9) years; range, 24 to 78 years) were enrolled. Before the operation, 8 feet combined with metatarsalgia, among them, 7 feet underwent modified Chevron+ Akin+ Weil osteotomy, and 1 foot underwent modified Chevron+ Weil osteotomy. Among the 44 feet without metatarsalgia, 11 feet underwent modified Chevron osteotomy and 33 feet underwent modified Chevron+ Akin osteotomy. The mean follow-up time was 17.8 months (12-24 months). The HVA angle decreased from 38.30°±7.59° before surgery to 10.00°±5.73° at the last follow-up; the IMA angle decreased from 16.08°(12.89°, 18.24°) to 4.81°(3.62°, 7.57°); the DMAA angle decreased from 18.35°(13.03°, 27.47°) to 4.52°(2.68°, 7.09°); JCA decreased significantly from 15.93°(10.25°, 23.06°) to 3.56°(1.71°, 6.98°); forefoot bone width decreased from (90.05±6.12) mm to (82.75±5.01) mm; forefoot soft tissue width decrease from 102.25(96.77, 107.15) mm to 98.08(91.01, 100.60) mm; the VAS decreased from 6(5.5, 7) points to 0(0, 0) points; the score according to the AOFAS/HMIS forefoot was increased from 49(42, 52.5) points to 90(83.5, 95) points; which were statistically significant compared with that before the operation (all P<0.01). There was no statistically significant difference in the first metatarsal length before the operation and at the last follow-up [54.60(52.86, 56.42) mm vs. 54.29(51.85, 56.35) mm, P>0.05]. In the post-operative period, there were 8 feet had limited metatarsophalangeal joint movement, 3 feet had limited interphalangeal joint movement, 5 feet had limited movement in both joints, which did not affect walking and function; 3 feet of partial recurrence of hallux valgus, 2 feet of screw irritation pain, 1 foot of cystic degeneration of the first metatarsal head, and no complications such as metastatic metatarsalgia. The satisfaction survey showed that the satisfaction rate of patients with the orthopedic effect was 90.4% (47/52). Conclusion:The modified Chevron osteotomy is effective in the treatment of moderate to severe hallux valgus with enlarged DMAA. Careful intraoperative operation and standardized postoperative rehabilitation training can reduce complications.
5.Exploring the protective effects of subnormothermic normoxic mechanical perfusion of genetically modified porcine erythrocyte perfusate on ischemic and hypoxic brain injury in cynomolgus monkeys
Shen LI ; Yanghui DONG ; Xiangyu SONG ; Pengkai LI ; Zhaodi MI ; Yixuan ZHU ; Mengyi CUI ; Xiwei PENG ; Long CHENG ; Man YUAN ; Wenjing XU ; Jiang PENG ; Yaqun ZHAO
Organ Transplantation 2025;16(5):728-737
Objective To explore the protective effects of genetically modified porcine erythrocyte suspension as a subnormothermic normoxic mechanical perfusate on hypoxic-ischemic brain injury in cynomolgus monkeys caused by traumatic hemorrhage.Methods Cynomolgus monkeys were randomly divided into positive and negative control groups(a total of 3 monkeys,with 3 left cerebral hemispheres as the positive control group and 3 right cerebral hemispheres as the negative control group)and the subnormothermic perfusion group(n=3).The positive control group was directly sampled 1 hour after circulatory arrest,while the negative control group was placed at subnormothermic conditions for 6 hours after circulatory arrest.The subnormothermic perfusion group underwent 6 hours of subnormothermic normoxic mechanical perfusion of the bilateral common carotid arteries of the cynomolgus monkey hypoxic-ischemic brain injury model using genetically modified porcine erythrocyte suspension 1 hour after circulatory arrest.Before perfusion,cross-matching experiments were conducted between the six genetically modified pig and the cynomolgus monkeys.After the start of perfusion,the levels of routine blood indicators in the perfusate were detected at 0,1,2,3,4,5 and 6 hours.Blood oxygen saturation was recorded,and the levels of Na+,K+,Ca2+,glucose and blood pH in the perfusate were measured,as well as the levels of IgG and IgM in the perfusate.After 6 hours of perfusion,the water content of the brain tissue was measured.Nissl staining was performed on the frontal cortex and hippocampal regions,and immunofluorescence staining was used to detect the expression of glial fibrillary acidic protein(GFAP),ionized calcium-binding adapter molecule 1(Iba1)and neuronal nuclear antigen(NEUN).Results The cross-matching results between the six genetically modified pig and the cynomolgus monkeys were negative.The number of red blood cells in the perfusate decreased significantly at 3 hours of perfusion,and the hemoglobin level showed a downward trend at 1,3,5 and 6 hours.The number of white blood cells and platelets decreased at all time points.The blood oxygen saturation in the subnormothermic perfusion group remained stable at 95%-98%,and the levels of blood oxygen saturation,Na+,Ca2+,glucose and pH were stable,while the K+level first increased and then decreased.There was no significant difference in the levels of IgG and IgM before and after perfusion.The water content of brain tissue at the end of perfusion in the subnormothermic perfusion group was significantly higher than that in the positive control group(P<0.001).Nissl staining results showed that compared with the positive control group,the pyramidal neurons in the prefrontal cortex of the subnormothermic perfusion group maintained better morphological integrity,with no significant increase in enlarged and deformed cells.In the hippocampal CA1 region,there was a slight increase in enlarged and deformed cells,and a few cells with undamaged structures showed reduced cell size.In the hippocampal dentate gyrus,fewer granule neurons had compromised structural integrity,with increased cell edema.NEUN immunofluorescence staining showed that compared with the positive control group,the pyramidal neurons in the prefrontal cortex and hippocampal CA1 region of the subnormothermic perfusion group had better morphological states,with clear axons.The granule cells in the hippocampal dentate gyrus were well preserved,but the nuclei were less well protected.GFAP immunofluorescence staining showed that compared with the positive control group,the subnormothermic perfusion group had sparser protrusions that were more tightly associated with neurons.Iba1 immunofluorescence staining showed that compared with the positive control group,the subnormothermic perfusion group had thicker and fewer protrusions.Conclusions Compared with the positive control group,subnormothermic normoxic mechanical perfusion with genetically modified porcine erythrocyte perfusate increases brain tissue edema in cynomolgus monkeys,but better preserves the morphological integrity of neurons and glial cells.The protective effects may be related to the continuous oxygen and energy supply,maintenance of ion homeostasis and perfusate pH,reduced rejection,and low metabolic state of the whole brain.
6.Advances and future research prospects in regulatory policies for clin-ical trials of artificial intelligence medical devices
Hao LIANG ; Shun WANG ; Cheng CUI ; Ling SONG ; Ailin SUN ; Man LI ; Jie QIAO ; Chun-li SONG ; Haiyan LI ; Yangguang ZHAO ; Haiyan LI ; Chenguang ZHANG ; Dongyang LIU
Chinese Journal of Clinical Pharmacology and Therapeutics 2025;30(3):427-431
Artificial intelligence(AI)has emerged as a cutting-edge technology leading the future and is a key engine for China's development.In the innovation and research of medical devices,AI has provided critical support in the areas of intelligent diagnostic assistance,intelligent therapeutic assis-tance,intelligent monitoring,life support,et al.Ma-chine learning-enabled device software functions(ML-DSFs)have become an essential component of many medical devices.Recently,the United States Food and Drug Administration(FDA)released a draft guidance titled"Marketing Submission Rec-ommendations for a Predetermined Change Con-trol Plan for Artificial Intelligence/Machine Learn-ing(AI/ML)-Enabled Device Software Functions(Draft)."that aimed to provide a forward-looking approach to foster the development of ML medical devices.By supporting iterative updates through modifications,this approach ensures the continu-ous safety and effectiveness of the devices.This guidance represents the latest in regulatory direc-tion and is especially beneficial for enhancing the quality and efficiency of clinical trials for AI prod-ucts.Therefore,we plan to provide a detailed intro-duction and interpretation of the guidance,with the aim of learning from international advanced regulatory concepts and experiences to promote the development of ML-DSFs with more profound international influence.
7.Active monitoring of ceftazidime-avibactam sodium-related adverse reactions of blood system and influencing factors
Ru WANG ; Mengqian QIAO ; Wanyue CHENG ; Man ZHU ; Hong YIN
Chinese Journal of Nosocomiology 2025;35(10):1557-1562
OBJECTIVE To acquire the real-world incidence of ceftazidime-avibactam sodium(CAZ)-related ad-verse reactions of blood system among a large sample of drug medication patients based on the active monitoring system so as to provide reference for safe clinical use of drugs.METHOD With the help of'Adverse Drug Event Active Surveillance and Assessment System-Ⅱ'(ADE-ASAS-Ⅱ),the use of CAZ of the patients who were hospi-talized in Chinese PLA General Hospital from Jan.1,2020 to Dec.31,2023 were retrospectively and automatical-ly monitored,the patients who were alarmed by system were evaluated by two persons,the incidence rates of CAZ-related thrombocytopenia,hemoglobin decreased and leucopenia were calculated,and the related influencing factors were analyzed.RESULTS Among the 278 case-times(191 cases)of patients who were treated with drugs and were enrolled in the study,there were 3(1.08%)case-times of thrombocytopenia,8(2.88%)case-times of hemoglobin decreased and 19(6.83%)case-times of leucopenia;the total incidence of adverse reactions of blood system was 10.79%.Logistic regression analysis showed that age and duration of drug administration were the in-fluencing factors for the CAZ-related adverse reactions of blood system.CONCLUSIONS It is common for the CAZ-related adverse reactions of blood system.The middle-aged and elderly patients who take drug therapy for a long time period are more likely to have the blood system-related adverse reactions.It is necessary to focus on the monitoring of renal function of the patients and adjust the dosage of administration in a timely manner so as to re-duce the incidence of adverse reactions of the blood system.
8.Analysis of Clinical Features and Multi-Slice Spiral CT Image Features of Acute Appendicitis in Soldiers Who Have Been Living in Plateau for A Long Time
Li-na YUE ; Juan-qin NIU ; Gang CHEN ; Man-ping CHENG ; Ning-xia MU ; Jia FAN ; Kang LIU ; Yu-lan NIU ; Ya-ping HE ; Zhong-hua LI
Progress in Modern Biomedicine 2025;25(11):1869-1878
Objective:To investigate the clinical features and multi-slice spiral computed tomography(CT)imaging features of acute appendicitis in soldiers who have been living in plateau for a long time.Methods:The clinical features and imaging data of 56 cases of acute appendicitis in soldiers who have been living in plateau for a long time confirmed by surgery from February 2022 to August 2024 were retrospectively analyzed.Results:In 56 cases with acute appendicitis in soldiers who have been living in plateau for a long time,the appendectomy position results showed:anterior ileum 4 cases(7.14%),lower ileum 10 cases(17.86%),posterior cecum 16 cases(28.57%),lower cecum 9 cases(16.07%),lateral cecum 2 cases(3.58%),posterior ileum 6 cases(10.71%),high(subhepatic)9 cases(16.07%),and left lower abdominal 0 cases,retroperitoneal appendicitis 0 cases,which was suggested that the anatomical position variation of appendicitis in soldiers with acute appendicitis who have been living at high altitude for a long time was relatively large.The direct manifestations of multi-slice spiral CT showed:appendectomy enlarged diameter>6 mm in 49 cases(87.50%),appendicular wall thickening>2 mm in 42 cases(75.00%),ppendiceal dilation lumen and effusion in 29 cases(51.79%),appendix indistinctness in 3 cases(5.36%),lppendix fecalith:27 cases(48.21%),gas in the appendix in 16 cases(28.57%).Indirect findings of multi-slice spiral CT showed that,periappendiceal exudation with shadow in 32 cases(57.14%),appendiceal cellulitis with peripheral abscess in 9 cases(16.07%),peritonitis and ascites in 13 cases(23.21%),ileocecal intestinal wall thickening in 22 cases(39.29%),mesenteric lymph node enlargement in 16 cases(28.57%),reflexive intestinal stasis in ileocecal region was observed in 19 cases(33.93%).Conclusion:In the officers and soldiers with acute appendicitis who lived at high altitude for a long time,multi-slice spiral CT showed the direct manifestations of appendiceal thickening,tube wall thickening,lumen dilatation,fluid accumulation,etc.,and the indirect manifestations were periappendiceal exudation with shadow,appendiceal cellulitis with peripheral abscess,ileocecal intestinal wall thickening,reflexes of small intestine and mesenteric lymph node enlargement.Multi-slice spiral CT has the advantages of clear and intuitive,high safety,high resolution and simple operation in the diagnosis of acute appendicitis.
9.Biomechanical Study of Different Design Schemes for Mandibular Angle Osteotomy Line
Man CHEN ; Yunzhang CHENG ; Yu QIAN ; Yichi ZHANG ; Li LIN ; Tianyi ZHANG ; Gang CHAI
Journal of Medical Biomechanics 2025;40(4):878-885
Objective To conduct preoperative simulations of three different osteotomy line design schemes under centric occlusion based on two distinct material assignment methods,evaluate biomechanical properties of the models,and explore which osteotomy line design schemes are more suitable for different types of mandibles.Methods Three types of mandibles were selected,and CT images were obtained for three-dimensional(3D)reconstruction.Material assignment was completed using the cortical/cancellous bone assignment method and the gray value assignment method.Osteotomy was simulated according to the three osteotomy line design schemes,followed by finite element analysis.Results In all simulation results of the mandibles,the maximum stress was 81.10 MPa,the maximum strain was 0.035 52,and the maximum displacement was 432.4 μm.The stress distributions obtained by the cortical/cancellous bone assignment method showed a larger stress distribution range than that that by the gray value assignment methods,but the maximum stress,strain,and displacement were generally lower.For the outflare type and common type mandibles,Scheme 1 showed lower maximum stress,strain,and displacement under both material assignment methods,but no clearly suitable scheme was found for the retracted type.Conclusions The outflare type and common type mandibles are more suitable for adopting the osteotomy line design scheme of Scheme 1.For the retracted type,other mandibular angle osteotomy plastic surgery methods may be considered to ensure better biomechanical characteristics.Whether choosing the osteotomy line design scheme or the modeling material assignment method,it is necessary to make the final decision based on the specific analysis objective and resource conditions.
10.Biomechanical Study of Different Design Schemes for Mandibular Angle Osteotomy Line
Man CHEN ; Yunzhang CHENG ; Yu QIAN ; Yichi ZHANG ; Li LIN ; Tianyi ZHANG ; Gang CHAI
Journal of Medical Biomechanics 2025;40(4):878-885
Objective To conduct preoperative simulations of three different osteotomy line design schemes under centric occlusion based on two distinct material assignment methods,evaluate biomechanical properties of the models,and explore which osteotomy line design schemes are more suitable for different types of mandibles.Methods Three types of mandibles were selected,and CT images were obtained for three-dimensional(3D)reconstruction.Material assignment was completed using the cortical/cancellous bone assignment method and the gray value assignment method.Osteotomy was simulated according to the three osteotomy line design schemes,followed by finite element analysis.Results In all simulation results of the mandibles,the maximum stress was 81.10 MPa,the maximum strain was 0.035 52,and the maximum displacement was 432.4 μm.The stress distributions obtained by the cortical/cancellous bone assignment method showed a larger stress distribution range than that that by the gray value assignment methods,but the maximum stress,strain,and displacement were generally lower.For the outflare type and common type mandibles,Scheme 1 showed lower maximum stress,strain,and displacement under both material assignment methods,but no clearly suitable scheme was found for the retracted type.Conclusions The outflare type and common type mandibles are more suitable for adopting the osteotomy line design scheme of Scheme 1.For the retracted type,other mandibular angle osteotomy plastic surgery methods may be considered to ensure better biomechanical characteristics.Whether choosing the osteotomy line design scheme or the modeling material assignment method,it is necessary to make the final decision based on the specific analysis objective and resource conditions.

Result Analysis
Print
Save
E-mail