Transalveolar technique for sinus floor elevation(TSFE)offers the advantages of minimal invasiveness,reduced postoperative reaction,and shorter operative time for vertical bone augmentation in the maxillary posterior region.The clinical data of one patient with severe deficiency of residual bone height(RBH)in the maxillary posterior region,a blood vessel visible in the lateral wall of the maxillary sinus and a visible septum at the floor of the maxillary sinus were reported,and two-stage flexible TSFE was used to improve the vertical bone height of the operated area while reducing trauma,the risk of Schneiderian membrane rupture and maxillary sinus infection,etc.,and the relevant literatures were reviewed.The patient,male,26 years old,complained of missing left maxillary posterior teeth for more than 1 year and requested restoration.The patient had 27 missing teeth,normal keratinized gingiva,full alveolar ridge,no elongation of the opposing teeth,fair width of the proximal and normal occlusal distance.The results of cone beam CT(CBCT)showed that the distance between the sinus crests at the site of the 27 teeth was about 3 mm,the width of the alveolar bone was about 12.8 mm,the bone density was normal,and there were no residual roots or other abnormalities;no cyst-like lesions were seen in the walls of the maxillary sinuses bilaterally,and separation was seen at the floor of the maxillary sinus on the left side and a blood vessel was seen in the lateral wall of the maxillary sinus.A diagnosis of Kennedy class Ⅱ maxillary tooth defects was made.After two stages of TSFE,the Schneiderian membrane was intact and the bone height of the implant area was elevated to 9.6 mm from 3 mm preoperatively after the completion of the restoration,with stable bone augmentation,good osseointegration,and restoration of normal occlusal function.For the patients with severe bone height deficiency in the maxillary posterior region,flexible two-stage TSFE should be considered,which can help to reduce the risk of maxillary sinus infection and Schneiderian membrane rupture while minimizing the damage and obtaining the ideal bone augmentation results.

Objective:To explore the spatial support capacity and its influence in osteogenic effect of composite biofilm based on poly(propylene carbonate)(PPC)/poly(butylene succinate)(PBS)in rabbit tibial bone defect models,and to clarify its barrier functional reliability and osteogenetic effect in vivo.Methods:The composite biofilms of PPC/PBS and PPC/PBS/collegen type Ⅰ(Col-Ⅰ)(PPC/PBS/Co)were prepared.Eighteen Japanese big-ear rabbits were selected and two bone defects were prepared on each side of the tibia of the rabbits.Six rabbits were randomly selected to place PPC/PBS composite biofilm on the bone defects,2 rabbits were executed at 2,4,8 and 12 weeks after operation,and the surface microstructures of PPC/PBS composite biofilm in the rabhit bone defect area were observed by scanning electron microscope(SEM).The experiment was divided into blank control group,PPC/PBS composite biofilm group,BME-10X collagen membrane group,and PPC/PBS/Co composite biofilm group.The above biofilms were placed on the corresponding bone defects of rabbits by operation,while no biofilm was placed in the rabbits in blank control group.Three rabbits were killed at 2,4,8 and 12 weeks after operation respectively,and the gray values of regenerated bone in the bone defect areas of the rabbits in varrous groups were detected by soft X-ray;the fluorescence intensities of regenerated bone tissue in the bone defect areas of the rabbits in various groups were observed by laser scanning confocal microscope after fluorescence labeling.The pathomorphology of regenerated bone tissue in the bone defect areas of the rabbits in various groups were observed by HE staining and modified Gomori staining,and the expression levels of bone morphogenetic protein 2(BMP-2)and osteopontin(OPN)in the regenerated bone tissue in bone defect areas of the rabbits in various groups were detected by immunohistochemical staining.Results:In general,the PPC/PBS composite biofilm was tightly covered in the bone defect area without displacement and collapse.The SEM results showed that the porous surface of PPC/PBS composite biofilm appeared micropore structure and the number of micropores was increased with the prolongation of time,while the smooth surface of biofilm basically did not form the micropore-like structure.The results of soft X-ray detection showed that the gray values of regenerated bone tissue in bone defect areas of the rabbits in various groups were increased with the prolongation of time,and the gray value of regenerated bone tissue in bone defect areas of the rabbits in PPC/PBS/Co composite biofilm group was significantly higher than those in other groups(P＜0.05).The confocal micrscope results showed that the fluorescence intensity of regenerated bone tissue in bone defect areas of the rabbits in PPC/PBS/Co composite biofilm group was similar to those in blank control group at 4,8,and 12 weeks;compared with PPC/PBS composite biofilm group and BME-10X collagen membrane group,the fluoresence intensity of regenerated bone tissue in bone defect areas of the rabbits in PPC/PB/Co composite biofilm group at 4 weeks was increased(P＜0.05),and the fluoresence intensity of regenerated bone tissue in bone defect areas of the rabbits at 8 and 12 weeks were decreased(P＜0.05).The results of HE staining and modified Gomori staining showed that compared with PPC/PBS composite biofilm group and BME-10X collagen membrane group,the new bone formed faster in PPC/PBS/Co composite biofilm group and blank control group at 2 and 4 weeks,and the lamellar bone mineralization was higher at 12 weeks.The immunohistochemical staining results showed that compared with blank control group,PPC/PBS composite biofilm group and BME-10X collagen membrane group,the expression levels of BMP-2 and OPN proteins in the regenerated bone tissue in bone defect areas of the rabbits in PPC/PBS/Co composite biofilm group at 2 and 4 weeks were increased(P＜0.05 or P＜0.01);compared with blank control group and PPC/PBS composite biofilm group,the expression levels of BMP-2 and OPN proteins in the regenerated bone tissue in bone defect areas of the rabbits in BME-10X collage membrane group were decreased(P＜0.05 or P＜0.01).Conclusion:PPC/PBS composite biofilm has excellent spatial support capacity and reliable physical barrier function.The PPC/PBS/Co composite biofilm has a good effect in guiding bone regeneration in vivo.

Objective To evaluate the clinical efficacy of kissing-stent implantation in the treatment of chronic iliac-vena cava occlusion.Methods The clinical data of 22 patients with chronic iliac-vena cava occlusion,who received kissing-stent implantation,were retrospectively analyzed.The surgical success rate and the procedure-related complications were recorded,the postoperative 3-,6-and 12-month stent patency rates were calculated,and the postoperative 6-month Villalta score was compared with its preoperative value.Results The technical success rate of kissing-stent implantation was 100％.No procedure-related surgical complications occurred.The postoperative 3-,6-and 12-month stent patency rates were 95.5％,90.9％and 86.1％respectively.The postoperative 6-month Villalta score was(12.14±2.80)points,which was remarkably lower than preoperative(20.91±3.16)points,the difference was statistically significant(P＜0.05).Conclusion The implantation of kissing-stent can successfully reconstruct iliac-vena cava with satisfactory short-term efficacy for chronic iliac-vena cava occlusion.