1.Study on mechanical stability of maxillary LeFort Ⅰ type osteotomy after fixation with mortise and tenon and absorbable plate
Yankun ZHANG ; Zixuan SHEN ; Ran ZHANG ; Lijia DONG ; Yu TIAN ; Li LU ; Mingliang YANG ; Guangqi YAN
Chinese Journal of Stomatology 2025;60(6):635-643
Objective:To evaluate the mechanical stability of the bone block after LeFort Ⅰ osteotomy with maxillary advancement using absorbable plates fixed with tenon-and-mortise structures.Methods:This study developed three finite element models: one for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with absorbable plates (Model 1); another for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with absorbable plates assisted by tenon-and-mortise structures (Model 2); and the last one for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with titanium plates and screws (Model 3). Simulated occlusal forces were applied on the anterior and posterior teeth in each model. The displacement changes of the nasal-palatine point (NP) and posterior nasal spine point (PNS) in the finite element coordinate system were compared and analyzed. The Mises equivalent stress distributions of the metal and absorbable plates were also examined to assess the mechanical stability of the three finite element models. Clinical data from 45 patients with dentofacial deformities treated from January 2017 to January 2023 at the Stomatology Hospital of China Medical University were collected. The age of the patients was 21±3 years. Among these, 15 patients had absorbable plates for fixation, 15 had absorbable plates assisted by tenon-and-mortise structures, and 15 had titanium plates and screws fixation after maxillary advancement. All patients underwent preoperative (T0), postoperative 3 days (T1), and 6 months (T2) spiral CT scans. The CT data in DICOM format were input into digital software, which was used to calculate the distances from the NP and PNS points to the horizontal plane (HP), right sagittal plane (FZSR), and coronal plane (CP) at T1 and T2. The distances at T1 and T2 were statistically analyzed using the Wilcoxon signed-rank test with SPSS 20.0, and a P value of<0.05 was considered statistically significant.Results:The finite element analysis showed that in the absorbable plate-only fixation group, the maximum displacement of the NP point (mm) under anterior and posterior tooth force conditions were 0.6 and 0.12, respectively, and for the PNS point, the maximum displacements were 0.5 and 0.11. In the tenon-and-mortise-assisted absorbable plate fixation group, the displacement of the NP point was 0.40 and 0.02 mm, and the displacement of the PNS point was 0.5 and 0.015 mm. In the titanium plate-screw fixation group, the NP point displacement was 0.33 and 0.055 mm, and the PNS point displacement was 0.16 and 0.1 mm. The Mises equivalent stress on the absorbable plates with tenon-and-mortise structure was significantly lower than that in the absorbable plate-only fixation group, while the titanium plate experienced the highest Mises equivalent stress. The clinical data analysis showed that in the horizontal direction, the postoperative stability of the three fixation methods was similar. However, in the vertical and anterior-posterior directions, the absorbable plate-only fixation group showed significant differences in the distances of PNS-HP, PNS-CP, and NP-CP between T1 and T2 ( P=0.018, P=0.009, P=0.017), suggesting significant postoperative bone displacement. In contrast, the tenon-and-mortise-assisted absorbable plate fixation group and the titanium plate-screw fixation group showed no significant differences in displacement during surgery and postoperatively(all P>0.05), demonstrating higher stability. Conclusions:The tenon-and-mortise-assisted absorbable plate fixation provides comparable stability to titanium plate fixation in clinical results, and it is more stable than absorbable plate-only fixation. In the mechanical study, when force was applied on the anterior teeth, the stability of the tenon-and-mortise-assisted absorbable plate fixation was slightly less than that of titanium plate fixation, but when posterior teeth were used, its stability exceeded both titanium plate fixation and absorbable plate-only fixation. The tenon-and-mortise-assisted absorbable plate fixation serves as an effective alternative to titanium plate fixation after LeFort Ⅰ osteotomy.
2.Microwave ablation for pediatric reninoma: a case report
Zhechen YU ; Guangqi ZENG ; Xiaoyu YUAN ; Tianyi WANG ; Yu ZHANG ; Ting FENG ; Guohui LI ; Ting ZHANG ; Mingcui FU ; Xiangming YAN ; Shu DAI
Chinese Journal of Urology 2025;46(5):395-396
Reninoma is a rare renal secretory tumor,prevalent in the young population. This disease is mostly surgically resected,and the use of microwave ablation to treat reninoma in children is scarce. A case of reninoma in a child was reported in this paper. The patient presented with refractory hypertension,hypokalemia,hyperreninemia and hyperaldosteronemia. Enhanced CT and contrast-enhanced ultrasound showed mass in the lower pole of the right kidney,which was considered as reninoma and microwave ablation was performed. The renin concentration decreased to 68.42 pg/ml at 4 hours after surgery. After 1 year of postoperative follow-up,there was no recurrence of hypertension and hypokalemia,and no signs of tumor recurrence were seen on repeated ultrasound examinations.
3.Study on mechanical stability of maxillary LeFort Ⅰ type osteotomy after fixation with mortise and tenon and absorbable plate
Yankun ZHANG ; Zixuan SHEN ; Ran ZHANG ; Lijia DONG ; Yu TIAN ; Li LU ; Mingliang YANG ; Guangqi YAN
Chinese Journal of Stomatology 2025;60(6):635-643
Objective:To evaluate the mechanical stability of the bone block after LeFort Ⅰ osteotomy with maxillary advancement using absorbable plates fixed with tenon-and-mortise structures.Methods:This study developed three finite element models: one for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with absorbable plates (Model 1); another for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with absorbable plates assisted by tenon-and-mortise structures (Model 2); and the last one for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with titanium plates and screws (Model 3). Simulated occlusal forces were applied on the anterior and posterior teeth in each model. The displacement changes of the nasal-palatine point (NP) and posterior nasal spine point (PNS) in the finite element coordinate system were compared and analyzed. The Mises equivalent stress distributions of the metal and absorbable plates were also examined to assess the mechanical stability of the three finite element models. Clinical data from 45 patients with dentofacial deformities treated from January 2017 to January 2023 at the Stomatology Hospital of China Medical University were collected. The age of the patients was 21±3 years. Among these, 15 patients had absorbable plates for fixation, 15 had absorbable plates assisted by tenon-and-mortise structures, and 15 had titanium plates and screws fixation after maxillary advancement. All patients underwent preoperative (T0), postoperative 3 days (T1), and 6 months (T2) spiral CT scans. The CT data in DICOM format were input into digital software, which was used to calculate the distances from the NP and PNS points to the horizontal plane (HP), right sagittal plane (FZSR), and coronal plane (CP) at T1 and T2. The distances at T1 and T2 were statistically analyzed using the Wilcoxon signed-rank test with SPSS 20.0, and a P value of<0.05 was considered statistically significant.Results:The finite element analysis showed that in the absorbable plate-only fixation group, the maximum displacement of the NP point (mm) under anterior and posterior tooth force conditions were 0.6 and 0.12, respectively, and for the PNS point, the maximum displacements were 0.5 and 0.11. In the tenon-and-mortise-assisted absorbable plate fixation group, the displacement of the NP point was 0.40 and 0.02 mm, and the displacement of the PNS point was 0.5 and 0.015 mm. In the titanium plate-screw fixation group, the NP point displacement was 0.33 and 0.055 mm, and the PNS point displacement was 0.16 and 0.1 mm. The Mises equivalent stress on the absorbable plates with tenon-and-mortise structure was significantly lower than that in the absorbable plate-only fixation group, while the titanium plate experienced the highest Mises equivalent stress. The clinical data analysis showed that in the horizontal direction, the postoperative stability of the three fixation methods was similar. However, in the vertical and anterior-posterior directions, the absorbable plate-only fixation group showed significant differences in the distances of PNS-HP, PNS-CP, and NP-CP between T1 and T2 ( P=0.018, P=0.009, P=0.017), suggesting significant postoperative bone displacement. In contrast, the tenon-and-mortise-assisted absorbable plate fixation group and the titanium plate-screw fixation group showed no significant differences in displacement during surgery and postoperatively(all P>0.05), demonstrating higher stability. Conclusions:The tenon-and-mortise-assisted absorbable plate fixation provides comparable stability to titanium plate fixation in clinical results, and it is more stable than absorbable plate-only fixation. In the mechanical study, when force was applied on the anterior teeth, the stability of the tenon-and-mortise-assisted absorbable plate fixation was slightly less than that of titanium plate fixation, but when posterior teeth were used, its stability exceeded both titanium plate fixation and absorbable plate-only fixation. The tenon-and-mortise-assisted absorbable plate fixation serves as an effective alternative to titanium plate fixation after LeFort Ⅰ osteotomy.
4.Microwave ablation for pediatric reninoma: a case report
Zhechen YU ; Guangqi ZENG ; Xiaoyu YUAN ; Tianyi WANG ; Yu ZHANG ; Ting FENG ; Guohui LI ; Ting ZHANG ; Mingcui FU ; Xiangming YAN ; Shu DAI
Chinese Journal of Urology 2025;46(5):395-396
Reninoma is a rare renal secretory tumor,prevalent in the young population. This disease is mostly surgically resected,and the use of microwave ablation to treat reninoma in children is scarce. A case of reninoma in a child was reported in this paper. The patient presented with refractory hypertension,hypokalemia,hyperreninemia and hyperaldosteronemia. Enhanced CT and contrast-enhanced ultrasound showed mass in the lower pole of the right kidney,which was considered as reninoma and microwave ablation was performed. The renin concentration decreased to 68.42 pg/ml at 4 hours after surgery. After 1 year of postoperative follow-up,there was no recurrence of hypertension and hypokalemia,and no signs of tumor recurrence were seen on repeated ultrasound examinations.
5.Efficacy of Autogenous Tooth Bone Graft Material for Patients with Alveolar Bone Deficiency in Orthodontic Treatment
Shuai LIU ; Rui ZHAO ; Junyan WANG ; Ruping TANG ; Guangqi YAN ; Mingliang YANG ; Zhenjin ZHAO
Journal of China Medical University 2019;48(2):105-108,113
Objective To evaluate the clinical effect of alveolar bone augmentation by applying autogenous tooth bone graft material to patients with alveolar bone deficiency in orthodontic treatment. Methods Four patients with a stable periodontal condition managed with fixed orthodontic treatment were included, and the number of graft sites was 17. Cone beam computed tomography (CBCT) showed labial alveolar bone deficiency. The treatment plan included extraction, and the extracted teeth were used to prepare autogenous tooth bone material. The alveolar bone width was measured at the same site at multiple heights prior to operation and at 3 and 6 months post-operation.Results The alveolar bone width was higher at both 3 and 6 months post-operatively (P < 0.05) than that pre-operatively. The alveolar bone width at 6 months post-operation was lower than that at 3 months post-operation (P < 0.05). Conclusion Applying autogenous tooth bone graft material to patients with alveolar bone deficiency in orthodontic treatment can expand the range of tooth movement and result in good clinical outcomes.
6. Distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015: results from a multicenter, retrospective study
Yike WAN ; Wei SANG ; Bing CHEN ; Yonggong YANG ; Luqin ZHANG ; Aining SUN ; Yuejun LIU ; Yang XU ; Yipeng CAI ; Chunbin WANG ; Yunfeng SHEN ; Yangwen JIANG ; Xiaoyan ZHANG ; Wei XU ; Ming HONG ; Tao CHEN ; Ruirong XU ; Feng LI ; Yanli XU ; Yan XUE ; Yilong LU ; Zhengmei HE ; Weimin DONG ; Ze CHEN ; Meihua JI ; Yueyan YANG ; Lijia ZHAI ; Yu ZHAO ; Guangqi WU ; Jiahua DING ; Jian CHENG ; Weibo CAI ; Yumei SUN ; Jian OUYANG
Chinese Journal of Hematology 2017;38(7):602-606
Objective:
To describe the distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015 to provide reference for empirical anti-infection treatment.
Methods:
Pathogens were from hematology department of 26 tertiary hospitals in Jiangsu Province from 2014 to 2015. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or agar dilution method. Collection of drug susceptibility results and corresponding patient data were analyzed.
Results:
The separated pathogens amounted to 4 306. Gram-negative bacteria accounted for 64.26%, while the proportions of gram-positive bacteria and funguses were 26.99% and 8.75% respectively. Common gram-negative bacteria were Escherichia coli (20.48%) , Klebsiella pneumonia (15.40%) , Pseudomonas aeruginosa (8.50%) , Acinetobacter baumannii (5.04%) and Stenotropho-monas maltophilia (3.41%) respectively. CRE amounted to 123 (6.68%) . Common gram-positive bacteria were Staphylococcus aureus (4.92%) , Staphylococcus hominis (4.88%) and Staphylococcus epidermidis (4.71%) respectively. Candida albicans were the main fungus which accounted for 5.43%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were 3.5%-6.1% and 5.0%-6.3% respectively. The rates of Pseudomonas aeruginosa resistant to tobramycin and amikacin were 3.2% and 3.3% respectively. The resistant rates of Acinetobacter baumannii towards tobramycin and cefoperazone/sulbactam were both 19.2%. The rates of Stenotrophomonas maltophilia resistant to minocycline and sulfamethoxazole were 3.5% and 9.3% respectively. The rates of Staphylococcus aureus, Enterococcus faecium and Enterococcus faecalis resistant wards vancomycin were 0, 6.4% and 1.4% respectively; also, the rates of them resistant to linezolid were 1.2%, 0 and 1.6% respectively; in addition, the rates of them resistant to teicoplanin were 2.8%, 14.3% and 8.0% respectively. Furthermore, MRSA accounted for 39.15% (83/212) .
Conclusions
Pathogens were mainly gram-negative bacteria. CRE accounted for 6.68%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were lower compared with other antibacterial agents. The rates of gram-positive bacteria resistant to vancomycin, linezolid and teicoplanin were still low. MRSA accounted for 39.15%.

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