BACKGROUND The conventional implant approach involves flap elevation,which may result in increased soft tissue and bone loss and postoperative morbidity.The flapless surgical technique,aided by three-dimensional medic...BACKGROUND The conventional implant approach involves flap elevation,which may result in increased soft tissue and bone loss and postoperative morbidity.The flapless surgical technique,aided by three-dimensional medical imaging equipment,is regarded as a possible alternative to the conventional approach to alleviate the above issues.Several studies have been performed regarding the role of flapless implant surgery.However,the results are inconsistent and there is no robust synthesis of long-term evidence to better inform surgeons regarding which type of surgical technique is more beneficial to the long-term prognosis of patients in need of implant insertion.AIM To compare the long-term clinical performance after flapless implant surgery to that after the conventional approach with flap elevation.METHODS PubMed,EMBASE,Cochrane Central Register of Controlled Trials,and grey literature databases were searched from inception to 23 September 2019.Randomised controlled trials (RCTs) and cohort studies comparing the long-term clinical performance after flapless implant surgery to that after the conventional approach over a follow-up of three years or more were induded.Meta-analyses were conducted to estimate the odds ratios (ORs) or mean differences (MDs) and their 95 To confidence intervals (CIs) between the long-term implant survival rate,marginal bone loss,and complication rate of the flapless and conventional groups.Subgroup analyses were carried out to account for the possible effects of the guided or free-hand method during flapless surgery.RESULTS Ten articles,including four RCTs and six cohort studies,satisfied the eligibility criteria and nine of them were inclded in the meta-analysis.There was no significant difference between the long-term implant survival rate [OR=1.30,95%CI (0.37,4.54),P=0.68],marginal bone loss [MD=0.01,95%CI (-0.42,0.44),P=0.97],and complication rate [OR=1.44,95%CI (0.77,2.68),P=0.25] after flapless implant surgery and the conventional approach.Moreover,subgroup analyses revealed that there was no statistically significant difference between the implant survival rate [guided:OR=1.52,95%CI (0.19,12.35),P=0.70];free-hand:n=1,could not be estimated),marginal bone loss [guided:MD=0.22,95%CI (-0.14,0.59),P=0.23;free-hand:MD=-0.27,95%CI (-1.10,0.57),P=0.53],or complication rate [guided:OR=1.16,95%CI (0.52,2.63),P=0.71;free-hand:OR=1.75,95%CI(0.66,4.63),P=0.26] in the flapless and conventional groups either with use of the surgical guide or by the free-hand method.CONCLUSION The flapless surgery and conventional approach had comparable clinical performance over three years or more.The guided or free-hand technique does not significantly affect the long-term outcomes of flapless surgery.展开更多
Purpose: The aim of this pilot study was to evaluate subjective and objective findings on short-term post-operative discomfort in patients receiving flapless implant surgery compared to traditional open flap surgery. ...Purpose: The aim of this pilot study was to evaluate subjective and objective findings on short-term post-operative discomfort in patients receiving flapless implant surgery compared to traditional open flap surgery. Materials and Methods: A two-centre, prospective survey study was conducted, using a customized questionnaire. Between December 2010 and January 2012, 20 patients were consecutively included. Eleven received conventional open-flap surgery and nine received flapless surgery. Inflammatory signs, analgesic consumption and sleeping difficulties were evaluated up to seven days postoperatively. A clinical examination was made one week postoperatively. Results: Significantly less experienced swelling was noted 24 hours after flapless surgery compared to open flap surgery for patients receiving four implants or more, and at three days postoperatively for patients receiving single implants. No difference concerning sleeping difficulties, pain or analgesic consumption was found. Clinical examination one week postoperatively showed no differences in wound gaps, redness of the mucosa, or presence of pus between the groups. Conclusions: In conclusion, flapless surgery seems to have a limited effect on postoperative comfort and short-term post-operative signs of soft tissue healing compared to open flap surgery. There is a need for larger randomized trials for evaluating differences in postoperative discomfort between the two surgical techniques.展开更多
The flying-wing aircraft has excellent aerodynamic efficiency and stealth performance.However,due to the lack of tails,the flying-wing aircraft has a serious attitude control problem.In this paper,the effective flow c...The flying-wing aircraft has excellent aerodynamic efficiency and stealth performance.However,due to the lack of tails,the flying-wing aircraft has a serious attitude control problem.In this paper,the effective flow control strategy of three-axis control is proposed by using continuous jets for a flapless flying-wing aircraft.The wind tunnel test of two kinds of flying-wing models,namely one flow control model and one mechanical control model,is conducted,and the control effect is analyzed and compared.By simultaneous blowing of the circulation control actuators inboard and differential blowing of the circulation control actuators outboard,the pitch and roll controls are achieved,respectively.It also has an effective control effect at very large angles of attack where the conventional control surface fails.A linear relationship is found between the increment of the controlled aerodynamic force/moment coefficient and the momentum coefficient for circulation control actuators.Moreover,to resolve the difficulty in yaw control,a novel wingtip jet is proposed based on the concept of the all-moving tip and compared with apex jet and circulation control jet.It is found that the wingtip jet is the most efficient actuator,followed by the simultaneous-blowing circulation control jet.Therefore,based on the research above,two optimized fluidic control configurations are proposed.One employs circulation control jet and wingtip jet,and the other is completely dependent on circulation control jet.Finally,the flow control mechanism of circulation control is discussed.Circulation control significantly accelerates the flow on the upper surface of the airfoil in attached flow and reduces the flow separation region in separated flow,leading to aerodynamic performance improvement.These results provide an important theoretic basis for the flapless flight control of flying-wing aircraft.展开更多
基金the Graduate Student's Research and Innovation Fund of Sichuan University,No.2018YJSY108the China Postdoctoral Science Foundation Funded Project,No.2018M640931+1 种基金the Science and Technology Key Research and Development Program of Sichuan Province,No.2019YFS0142the National Natural Science Foundation of China,No.81901060.
文摘BACKGROUND The conventional implant approach involves flap elevation,which may result in increased soft tissue and bone loss and postoperative morbidity.The flapless surgical technique,aided by three-dimensional medical imaging equipment,is regarded as a possible alternative to the conventional approach to alleviate the above issues.Several studies have been performed regarding the role of flapless implant surgery.However,the results are inconsistent and there is no robust synthesis of long-term evidence to better inform surgeons regarding which type of surgical technique is more beneficial to the long-term prognosis of patients in need of implant insertion.AIM To compare the long-term clinical performance after flapless implant surgery to that after the conventional approach with flap elevation.METHODS PubMed,EMBASE,Cochrane Central Register of Controlled Trials,and grey literature databases were searched from inception to 23 September 2019.Randomised controlled trials (RCTs) and cohort studies comparing the long-term clinical performance after flapless implant surgery to that after the conventional approach over a follow-up of three years or more were induded.Meta-analyses were conducted to estimate the odds ratios (ORs) or mean differences (MDs) and their 95 To confidence intervals (CIs) between the long-term implant survival rate,marginal bone loss,and complication rate of the flapless and conventional groups.Subgroup analyses were carried out to account for the possible effects of the guided or free-hand method during flapless surgery.RESULTS Ten articles,including four RCTs and six cohort studies,satisfied the eligibility criteria and nine of them were inclded in the meta-analysis.There was no significant difference between the long-term implant survival rate [OR=1.30,95%CI (0.37,4.54),P=0.68],marginal bone loss [MD=0.01,95%CI (-0.42,0.44),P=0.97],and complication rate [OR=1.44,95%CI (0.77,2.68),P=0.25] after flapless implant surgery and the conventional approach.Moreover,subgroup analyses revealed that there was no statistically significant difference between the implant survival rate [guided:OR=1.52,95%CI (0.19,12.35),P=0.70];free-hand:n=1,could not be estimated),marginal bone loss [guided:MD=0.22,95%CI (-0.14,0.59),P=0.23;free-hand:MD=-0.27,95%CI (-1.10,0.57),P=0.53],or complication rate [guided:OR=1.16,95%CI (0.52,2.63),P=0.71;free-hand:OR=1.75,95%CI(0.66,4.63),P=0.26] in the flapless and conventional groups either with use of the surgical guide or by the free-hand method.CONCLUSION The flapless surgery and conventional approach had comparable clinical performance over three years or more.The guided or free-hand technique does not significantly affect the long-term outcomes of flapless surgery.
文摘Purpose: The aim of this pilot study was to evaluate subjective and objective findings on short-term post-operative discomfort in patients receiving flapless implant surgery compared to traditional open flap surgery. Materials and Methods: A two-centre, prospective survey study was conducted, using a customized questionnaire. Between December 2010 and January 2012, 20 patients were consecutively included. Eleven received conventional open-flap surgery and nine received flapless surgery. Inflammatory signs, analgesic consumption and sleeping difficulties were evaluated up to seven days postoperatively. A clinical examination was made one week postoperatively. Results: Significantly less experienced swelling was noted 24 hours after flapless surgery compared to open flap surgery for patients receiving four implants or more, and at three days postoperatively for patients receiving single implants. No difference concerning sleeping difficulties, pain or analgesic consumption was found. Clinical examination one week postoperatively showed no differences in wound gaps, redness of the mucosa, or presence of pus between the groups. Conclusions: In conclusion, flapless surgery seems to have a limited effect on postoperative comfort and short-term post-operative signs of soft tissue healing compared to open flap surgery. There is a need for larger randomized trials for evaluating differences in postoperative discomfort between the two surgical techniques.
文摘The flying-wing aircraft has excellent aerodynamic efficiency and stealth performance.However,due to the lack of tails,the flying-wing aircraft has a serious attitude control problem.In this paper,the effective flow control strategy of three-axis control is proposed by using continuous jets for a flapless flying-wing aircraft.The wind tunnel test of two kinds of flying-wing models,namely one flow control model and one mechanical control model,is conducted,and the control effect is analyzed and compared.By simultaneous blowing of the circulation control actuators inboard and differential blowing of the circulation control actuators outboard,the pitch and roll controls are achieved,respectively.It also has an effective control effect at very large angles of attack where the conventional control surface fails.A linear relationship is found between the increment of the controlled aerodynamic force/moment coefficient and the momentum coefficient for circulation control actuators.Moreover,to resolve the difficulty in yaw control,a novel wingtip jet is proposed based on the concept of the all-moving tip and compared with apex jet and circulation control jet.It is found that the wingtip jet is the most efficient actuator,followed by the simultaneous-blowing circulation control jet.Therefore,based on the research above,two optimized fluidic control configurations are proposed.One employs circulation control jet and wingtip jet,and the other is completely dependent on circulation control jet.Finally,the flow control mechanism of circulation control is discussed.Circulation control significantly accelerates the flow on the upper surface of the airfoil in attached flow and reduces the flow separation region in separated flow,leading to aerodynamic performance improvement.These results provide an important theoretic basis for the flapless flight control of flying-wing aircraft.
