This article reviews the literatures dealing with the lingualized occlusion of complete denture including the origin,development and research.Lingualized occlusion is a valuable concept because many advantages of anat...This article reviews the literatures dealing with the lingualized occlusion of complete denture including the origin,development and research.Lingualized occlusion is a valuable concept because many advantages of anatomic and nonanatomic occlusions are retained,satisfactory occlusion is easily obtained,balanced occlusion can be accomplished.展开更多
OBJECTIVE To study the role of Ginkgo biloba extract-761(EGb-761)in the recovery of gait abnormality and its neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlu-sion in ra...OBJECTIVE To study the role of Ginkgo biloba extract-761(EGb-761)in the recovery of gait abnormality and its neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlu-sion in rats.METHODS Male Sprague Dawley rats(n=200,240-305 g)were anesthetized with 0.2%pentobarbital sodium diluted in physiological saline(2.0 m L·kg-1,ip).Then a monofilament coated with poly-L-lysine,was used to occlude the origin of the middle cerebral artery.It was inserted into the internal carotid artery lumen until it met mild resistance,approximately 20mm beyond the common carotid artery bifurcation.The suture was secured with a ligature and maintained in place until sacrifice.The same surgical procedure was conducted in sham-operated rats in which the middle cerebral artery was not occluded.Motor and behavioral changes were assessed after surgery using a five point scale.The rats securing the point scale above 2 were included in the study.The rats were randomly divided into control,and treated groups:EGb-761(20,50,and 100 mg·kg-1).The treated groups were oral y administered(10 mL·kg-1)for 28 d.On 7th,14th,21st,and 28th day the neurological scores,rotar rod test and gait assessment(the automated computer-assisted method)were performed.The brains were collected for TTC staining and histopathological analysis.RESULTS 1)Weight:On 28th day,EGb-761(20 mg·kg-1,)significantly increased the weight of the rat by^8%as compared to control(~300 g).However,at 50 mg·kg-1,and 100 mg·kg-1,a significant increase of^7-7.6%(control:~232 g),and^7.3-7%,respectively from 14 to 28 days was noted.2)Neurological scores:On 28thday,EGb-761(20,50,and 100 mg·kg-1)significantly decreased the neurological scores by^18%,~22%,~21%,respectively as compared to control(~2.07).3)Rotar rod test:On 28thday,EGb-761(50,and100 mg·kg-1)significantly increased by^69.1%,~74.1%,respectively as compared to control(~28.2).4)Gait assessment:On 7th,14th,21st,and 28thday,EGb-761(20,50,and 100 m·kg-1)significantly reduced the average body angle,on 7th,14th,21st,and 28thday,EGb-761(100 mg·kg-1)significantly increased the walk speed and reduced the average walking cycle,EGb-761(50,and 100 mg·kg-1)significantly the area of the left brain/right brain area percentage and reduced tissue pathologic neuron injury.CONCLUSION Ginkgo biloba extract EGb-761 has obvious improve behavior disorders,and has a protective neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlusion.展开更多
Objective To summarize the clinical characteristics and the effect of pulmonary endarterectomy(PEA)in CTEPH patients with unilateral main pulmonary artery occlusion.Methods Of 160 CTEPH patients operated between Janua...Objective To summarize the clinical characteristics and the effect of pulmonary endarterectomy(PEA)in CTEPH patients with unilateral main pulmonary artery occlusion.Methods Of 160 CTEPH patients operated between January2004 and March 2018 at our center,13(8.1%)had complete main pulmonary artery occlusion.Patients were included if the ventilation/perfusion(V/Q)scan revealed nonperfusion of an entire lung and the pathological examination showed chronic thromboembolic.展开更多
Objective Introduction When we perform transvenous embolization of carotid cavernous fistula, we selectively occluded the venous outflow to the retrograde cortical venous drainage and retrograde ophthalmic venous drai...Objective Introduction When we perform transvenous embolization of carotid cavernous fistula, we selectively occluded the venous outflow to the retrograde cortical venous drainage and retrograde ophthalmic venous drainage as the initial steps before the rest of the cavernous sinus. The rationale is to prevent re-diversion of flow into the ophthalmic veins and cortical veins in a subtotally occluded carotid cavernous fistula.Method From 1997 to 2004, a total of 46 patients with carotid cavernous fistula were treated by transvenous embolization using the proposed selective occlusion strategy. There were 6 direct and 40 dural cartoid cavernous fistulae. The embolic agents were Guglielmi detachable coils and fibered platinum coils. Transvenous embolization routes included inferior petrosal sinus (IPS) alone (32 patients), IPS and intercavernous sinus (9 patients), and superior ophthalmic vein (5 patients).Result The follow-up period ranged from 4 months to 7 years. One patient developed retinal hemorrhage due to ophthalic vein thrombosis one week after the embolization procedure. Two patients had transient ophthalmoplegia and 2 patients had symptomatic recurrence of the carotid cavernous fistula during the follow-up. Clinical cure was achieved in 44 patients (96%).Conclusion The sequential occlusion strategy offers a safe and effective method in the transvenous embolization of carotid cavernous fistula.展开更多
Objective:To investigate the effects of electro-acupuncture preconditioning on focal cerebral blood flow(CBF)in artery and vein of rats with middle cerebral artery occlusion(MCAO),and to provide experimental evidences...Objective:To investigate the effects of electro-acupuncture preconditioning on focal cerebral blood flow(CBF)in artery and vein of rats with middle cerebral artery occlusion(MCAO),and to provide experimental evidences for primary prevention of ischemic stroke.Method:Eighteen male Sprague-Dawley rats(two months old)were divided into 3 groups:electro-acupuncture preconditioning group(EA group),ischemia group(Is group)and Dazhui and Baihui sham group(six rats per group).The rats in the EA group were given electro-acupuncture preconditioning at Dazhui and Baihui with 2/15 density wave current for 30 minutes per day,5 days consecutively.After preconditioning,enhanced laser speckle contrast analysis was implemented to get false color images before making middle cerebral ischemia occlusion model.Then getting false color images two hours during ischemia by laser speckle contrast analysis again.Result:④Relative CBF in focal cortical artery:There were significant differences at every time point in EA group and Is group(P<0.01,P<0.05)comparing with that before occlusion respectively.Compared with that before ischemia,there was significant difference at 120 min after ischemia in sham group(P<0.05);compared with that at 30 min after occlusion,there was significant difference at every time point in EA group from the time point 60 min after occlusion;there was significant difference at every time point in EA group and Is group(P<0.05)comparing with sham group;Compared with sham group,there was significant difference at 30min and 60 min after ischemia in EA group(P<0.05).④Relative CBF in focal cortical vein:There was significant difference at every time point in sham group comparing with that before occlusion(P<0.05);compared with that before occlusion,there was significant difference from 45 min after occlusion in EA group(P<0.05);compared with that before occlusion,there was significant difference from 105 min after occlusion in sham group(P<0.05);there was significant difference at 120 min after occlusion comparing with 60 min after occlusion in EA group;compared with sham group,there was significant difference at every time point in EA group and Is group(except 30 min after occlusion)(P<0.05),respectively;compared with Is group,there was significant difference at 30,45,60 min after occlusion in EA group(P<0.05).④The infarct brain volume detected 24 h after reperfusion in EA group was significantly smaller comparing with that in Is group(P<0.05).Conclusion:Electro-acupuncture preconditioning could increase CBF velocity in artery and vein of focal cortex in rats with MCAO,which also had time-dependence.Additionally,electro-acupuncture preconditioning could decrease the infarct volume detected 24h after reperfusion,which possibly was correlated with the blood supply in ischemic penumbra.展开更多
目的研究冠状动脉CT血管成像(CCTA)评价冠状动脉慢性完全闭塞病变(chronic total occlusion,CTO)形态学参数在介入治疗指导中的应用价值。方法选取2021年1月至2023年12月金华市人民医院收治的经冠状动脉造影(ICA)证实的CTO患者300例,患...目的研究冠状动脉CT血管成像(CCTA)评价冠状动脉慢性完全闭塞病变(chronic total occlusion,CTO)形态学参数在介入治疗指导中的应用价值。方法选取2021年1月至2023年12月金华市人民医院收治的经冠状动脉造影(ICA)证实的CTO患者300例,患者术前均接受CCTA检查。记录CCTA形态学参数闭塞段近端形态、闭塞血管长度、闭塞段内线样强化长度、闭塞段内线样强化长度/闭塞血管长度、闭塞段血管线样强化、闭塞段内血管钙化情况、闭塞段内血管钙化面积≥横截面50%、病变走行迂曲(>45°)、侧支血管情况、血管开口病变,并分析以上参数与PCI治疗结果的关系。结果300例CTO患者病变共325处,PCI治疗成功227处(69.85%),PCI治疗失败98处(30.15%);失败组闭塞段近端钝形、闭塞血管长度、闭塞段内血管钙化面积≥横截面50%、病变走行迂曲(>45°)明显高于成功组(P<0.05),闭塞段内线样强化长度、闭塞段内线样强化长度/闭塞血管长度、闭塞段内线样强化明显低于成功组(P<0.05),两组其余参数差异均无统计学意义(P>0.05);多因素logistic回归分析结果显示,闭塞段内线样强化长度(OR=1.975,95%CI:1.306~2.988)、闭塞段内线样强化长度/闭塞血管长度(OR=3.831,95%CI:1.332~11.017)、闭塞段内线样强化(OR=1.702,95%CI:1.007~2.879)是预测PCI治疗成功的相关因素(P<0.05)。结论CCTA评价冠状动脉CTO形态学参数在介入治疗中具有一定的指导作用,其中闭塞段内线样强化长度、闭塞段内线样强化长度/闭塞血管长度、闭塞段内线样强化是预测PCI治疗成功的相关因素。展开更多
目的:对混合牙列儿童的咬合力和咬合接触进行测量分析,初步提供混合牙列个别正常[牙合]儿童咬合情况的基线数据。方法:采用横断面研究,共纳入20例混合牙列个别正常[牙合]儿童,其中男童12例,女童8例,年龄在6.5~9.8岁。使用Dental Prescal...目的:对混合牙列儿童的咬合力和咬合接触进行测量分析,初步提供混合牙列个别正常[牙合]儿童咬合情况的基线数据。方法:采用横断面研究,共纳入20例混合牙列个别正常[牙合]儿童,其中男童12例,女童8例,年龄在6.5~9.8岁。使用Dental PrescaleⅡ咬合分析系统进行牙尖交错位时咬合力和咬合接触的测量,包括全牙列最大咬合力(N)及咬合接触面积(mm^(2))、左右双侧最大咬合力及咬合接触面积、平均咬合压强(MPa)、最大咬合压强(MPa),并确定咬合力重心位置。对最大咬合力、平均咬合压强、咬合接触面积的性别差异进行分析,比较混合牙列个别正常[牙合]儿童咬合的双侧对称性,对咬合数据与年龄、身高、体质量、体重指数(body mass index,BMI)的相关性进行分析。结果:(1)20例混合牙列儿童在牙尖交错位时平均最大咬合力为(869.18±106.64)N,平均咬合接触面积为(25.19±2.89)mm^(2),平均咬合压强为(34.37±5.98)MPa,最大咬合压强中位数(P_(25),P_(75))为120(120,120)MPa;(2)左右双侧在最大咬合力、咬合接触面积、平均咬合压强、最大咬合压强上差异无统计学意义(P>0.05);(3)牙尖交错位时,12例男童和8例女童的平均咬合接触面积分别为(26.71±3.91)mm^(2)和(21.62±3.08)mm^(2),平均最大咬合力分别为(911.92±145.05)N和(769.47±116.45)N,差异有统计学意义(P<0.05),而平均咬合压强在男童和女童间差异无统计学意义(P>0.05);(4)牙尖交错位时的最大咬合力与年龄呈弱相关(r=0.219,P=0.046),与咬合接触面积呈极强的正相关(r=0.949,P<0.001),平均咬合压强、最大咬合压强、咬合接触面积与年龄、身高、体质量、BMI均无相关性;(5)20例混合牙列个别正常[牙合]儿童的咬合重心均位于磨牙区,最大咬合压强点有7例儿童仅位于第一恒磨牙区,有10例儿童在乳磨牙区和第一恒磨牙区均存在,有3例儿童仅位于乳磨牙区。结论:混合牙列个别正常[牙合]儿童在牙尖交错位时的最大咬合力、咬合接触面积、平均咬合压强、最大咬合压强双侧对称性良好;最大咬合力、咬合接触面积存在性别差异,男童大于女童;最大咬合力与咬合接触面积呈正相关。展开更多
在基于增强现实装配引导的复杂零/部件装配场景中,由于手部对零/部件的遮挡,导致零件位姿解算时产生较大的误差,甚至造成求解失败。目前针对手工装配零件的位姿估计算法在解决零件遮挡问题时没有考虑手部信息,使得位姿估计精度难以满足...在基于增强现实装配引导的复杂零/部件装配场景中,由于手部对零/部件的遮挡,导致零件位姿解算时产生较大的误差,甚至造成求解失败。目前针对手工装配零件的位姿估计算法在解决零件遮挡问题时没有考虑手部信息,使得位姿估计精度难以满足增强装配实际应用的要求。针对上述问题,提出了融合手部姿态的零件6D位姿估计算法,即HandICG算法。该算法将手部的姿态信息与迭代对应几何(Iterative Corresponding Geometry,ICG)算法进行融合,当发生手部遮挡时,将手部的姿态信息应用到零件姿态的求解中,从而显著提高手部遮挡情况下零件位姿估计的精度,实验表明,平均模型点距离(Average Distance of Model points,ADD)相关评价指标达到74.73%,是ICG算法的2.61倍。该算法显著提升了增强装配场景中零件位姿解算的准确性和鲁棒性。展开更多
文摘This article reviews the literatures dealing with the lingualized occlusion of complete denture including the origin,development and research.Lingualized occlusion is a valuable concept because many advantages of anatomic and nonanatomic occlusions are retained,satisfactory occlusion is easily obtained,balanced occlusion can be accomplished.
基金The project supported by Hunan province Science and Technology Plan Projects of China(2015DK3010)
文摘OBJECTIVE To study the role of Ginkgo biloba extract-761(EGb-761)in the recovery of gait abnormality and its neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlu-sion in rats.METHODS Male Sprague Dawley rats(n=200,240-305 g)were anesthetized with 0.2%pentobarbital sodium diluted in physiological saline(2.0 m L·kg-1,ip).Then a monofilament coated with poly-L-lysine,was used to occlude the origin of the middle cerebral artery.It was inserted into the internal carotid artery lumen until it met mild resistance,approximately 20mm beyond the common carotid artery bifurcation.The suture was secured with a ligature and maintained in place until sacrifice.The same surgical procedure was conducted in sham-operated rats in which the middle cerebral artery was not occluded.Motor and behavioral changes were assessed after surgery using a five point scale.The rats securing the point scale above 2 were included in the study.The rats were randomly divided into control,and treated groups:EGb-761(20,50,and 100 mg·kg-1).The treated groups were oral y administered(10 mL·kg-1)for 28 d.On 7th,14th,21st,and 28th day the neurological scores,rotar rod test and gait assessment(the automated computer-assisted method)were performed.The brains were collected for TTC staining and histopathological analysis.RESULTS 1)Weight:On 28th day,EGb-761(20 mg·kg-1,)significantly increased the weight of the rat by^8%as compared to control(~300 g).However,at 50 mg·kg-1,and 100 mg·kg-1,a significant increase of^7-7.6%(control:~232 g),and^7.3-7%,respectively from 14 to 28 days was noted.2)Neurological scores:On 28thday,EGb-761(20,50,and 100 mg·kg-1)significantly decreased the neurological scores by^18%,~22%,~21%,respectively as compared to control(~2.07).3)Rotar rod test:On 28thday,EGb-761(50,and100 mg·kg-1)significantly increased by^69.1%,~74.1%,respectively as compared to control(~28.2).4)Gait assessment:On 7th,14th,21st,and 28thday,EGb-761(20,50,and 100 m·kg-1)significantly reduced the average body angle,on 7th,14th,21st,and 28thday,EGb-761(100 mg·kg-1)significantly increased the walk speed and reduced the average walking cycle,EGb-761(50,and 100 mg·kg-1)significantly the area of the left brain/right brain area percentage and reduced tissue pathologic neuron injury.CONCLUSION Ginkgo biloba extract EGb-761 has obvious improve behavior disorders,and has a protective neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlusion.
文摘Objective To summarize the clinical characteristics and the effect of pulmonary endarterectomy(PEA)in CTEPH patients with unilateral main pulmonary artery occlusion.Methods Of 160 CTEPH patients operated between January2004 and March 2018 at our center,13(8.1%)had complete main pulmonary artery occlusion.Patients were included if the ventilation/perfusion(V/Q)scan revealed nonperfusion of an entire lung and the pathological examination showed chronic thromboembolic.
文摘Objective Introduction When we perform transvenous embolization of carotid cavernous fistula, we selectively occluded the venous outflow to the retrograde cortical venous drainage and retrograde ophthalmic venous drainage as the initial steps before the rest of the cavernous sinus. The rationale is to prevent re-diversion of flow into the ophthalmic veins and cortical veins in a subtotally occluded carotid cavernous fistula.Method From 1997 to 2004, a total of 46 patients with carotid cavernous fistula were treated by transvenous embolization using the proposed selective occlusion strategy. There were 6 direct and 40 dural cartoid cavernous fistulae. The embolic agents were Guglielmi detachable coils and fibered platinum coils. Transvenous embolization routes included inferior petrosal sinus (IPS) alone (32 patients), IPS and intercavernous sinus (9 patients), and superior ophthalmic vein (5 patients).Result The follow-up period ranged from 4 months to 7 years. One patient developed retinal hemorrhage due to ophthalic vein thrombosis one week after the embolization procedure. Two patients had transient ophthalmoplegia and 2 patients had symptomatic recurrence of the carotid cavernous fistula during the follow-up. Clinical cure was achieved in 44 patients (96%).Conclusion The sequential occlusion strategy offers a safe and effective method in the transvenous embolization of carotid cavernous fistula.
基金supported by the Natural Science Foundation of China(NSFC,NO.81171856,81171855)the Development Program of China(863 program,NO.2007AA02Z482)the Key projects of Shanghai Science and Technology on Biomedicine(NO.10DZ1950800)
文摘Objective:To investigate the effects of electro-acupuncture preconditioning on focal cerebral blood flow(CBF)in artery and vein of rats with middle cerebral artery occlusion(MCAO),and to provide experimental evidences for primary prevention of ischemic stroke.Method:Eighteen male Sprague-Dawley rats(two months old)were divided into 3 groups:electro-acupuncture preconditioning group(EA group),ischemia group(Is group)and Dazhui and Baihui sham group(six rats per group).The rats in the EA group were given electro-acupuncture preconditioning at Dazhui and Baihui with 2/15 density wave current for 30 minutes per day,5 days consecutively.After preconditioning,enhanced laser speckle contrast analysis was implemented to get false color images before making middle cerebral ischemia occlusion model.Then getting false color images two hours during ischemia by laser speckle contrast analysis again.Result:④Relative CBF in focal cortical artery:There were significant differences at every time point in EA group and Is group(P<0.01,P<0.05)comparing with that before occlusion respectively.Compared with that before ischemia,there was significant difference at 120 min after ischemia in sham group(P<0.05);compared with that at 30 min after occlusion,there was significant difference at every time point in EA group from the time point 60 min after occlusion;there was significant difference at every time point in EA group and Is group(P<0.05)comparing with sham group;Compared with sham group,there was significant difference at 30min and 60 min after ischemia in EA group(P<0.05).④Relative CBF in focal cortical vein:There was significant difference at every time point in sham group comparing with that before occlusion(P<0.05);compared with that before occlusion,there was significant difference from 45 min after occlusion in EA group(P<0.05);compared with that before occlusion,there was significant difference from 105 min after occlusion in sham group(P<0.05);there was significant difference at 120 min after occlusion comparing with 60 min after occlusion in EA group;compared with sham group,there was significant difference at every time point in EA group and Is group(except 30 min after occlusion)(P<0.05),respectively;compared with Is group,there was significant difference at 30,45,60 min after occlusion in EA group(P<0.05).④The infarct brain volume detected 24 h after reperfusion in EA group was significantly smaller comparing with that in Is group(P<0.05).Conclusion:Electro-acupuncture preconditioning could increase CBF velocity in artery and vein of focal cortex in rats with MCAO,which also had time-dependence.Additionally,electro-acupuncture preconditioning could decrease the infarct volume detected 24h after reperfusion,which possibly was correlated with the blood supply in ischemic penumbra.
文摘目的研究冠状动脉CT血管成像(CCTA)评价冠状动脉慢性完全闭塞病变(chronic total occlusion,CTO)形态学参数在介入治疗指导中的应用价值。方法选取2021年1月至2023年12月金华市人民医院收治的经冠状动脉造影(ICA)证实的CTO患者300例,患者术前均接受CCTA检查。记录CCTA形态学参数闭塞段近端形态、闭塞血管长度、闭塞段内线样强化长度、闭塞段内线样强化长度/闭塞血管长度、闭塞段血管线样强化、闭塞段内血管钙化情况、闭塞段内血管钙化面积≥横截面50%、病变走行迂曲(>45°)、侧支血管情况、血管开口病变,并分析以上参数与PCI治疗结果的关系。结果300例CTO患者病变共325处,PCI治疗成功227处(69.85%),PCI治疗失败98处(30.15%);失败组闭塞段近端钝形、闭塞血管长度、闭塞段内血管钙化面积≥横截面50%、病变走行迂曲(>45°)明显高于成功组(P<0.05),闭塞段内线样强化长度、闭塞段内线样强化长度/闭塞血管长度、闭塞段内线样强化明显低于成功组(P<0.05),两组其余参数差异均无统计学意义(P>0.05);多因素logistic回归分析结果显示,闭塞段内线样强化长度(OR=1.975,95%CI:1.306~2.988)、闭塞段内线样强化长度/闭塞血管长度(OR=3.831,95%CI:1.332~11.017)、闭塞段内线样强化(OR=1.702,95%CI:1.007~2.879)是预测PCI治疗成功的相关因素(P<0.05)。结论CCTA评价冠状动脉CTO形态学参数在介入治疗中具有一定的指导作用,其中闭塞段内线样强化长度、闭塞段内线样强化长度/闭塞血管长度、闭塞段内线样强化是预测PCI治疗成功的相关因素。
文摘目的:对混合牙列儿童的咬合力和咬合接触进行测量分析,初步提供混合牙列个别正常[牙合]儿童咬合情况的基线数据。方法:采用横断面研究,共纳入20例混合牙列个别正常[牙合]儿童,其中男童12例,女童8例,年龄在6.5~9.8岁。使用Dental PrescaleⅡ咬合分析系统进行牙尖交错位时咬合力和咬合接触的测量,包括全牙列最大咬合力(N)及咬合接触面积(mm^(2))、左右双侧最大咬合力及咬合接触面积、平均咬合压强(MPa)、最大咬合压强(MPa),并确定咬合力重心位置。对最大咬合力、平均咬合压强、咬合接触面积的性别差异进行分析,比较混合牙列个别正常[牙合]儿童咬合的双侧对称性,对咬合数据与年龄、身高、体质量、体重指数(body mass index,BMI)的相关性进行分析。结果:(1)20例混合牙列儿童在牙尖交错位时平均最大咬合力为(869.18±106.64)N,平均咬合接触面积为(25.19±2.89)mm^(2),平均咬合压强为(34.37±5.98)MPa,最大咬合压强中位数(P_(25),P_(75))为120(120,120)MPa;(2)左右双侧在最大咬合力、咬合接触面积、平均咬合压强、最大咬合压强上差异无统计学意义(P>0.05);(3)牙尖交错位时,12例男童和8例女童的平均咬合接触面积分别为(26.71±3.91)mm^(2)和(21.62±3.08)mm^(2),平均最大咬合力分别为(911.92±145.05)N和(769.47±116.45)N,差异有统计学意义(P<0.05),而平均咬合压强在男童和女童间差异无统计学意义(P>0.05);(4)牙尖交错位时的最大咬合力与年龄呈弱相关(r=0.219,P=0.046),与咬合接触面积呈极强的正相关(r=0.949,P<0.001),平均咬合压强、最大咬合压强、咬合接触面积与年龄、身高、体质量、BMI均无相关性;(5)20例混合牙列个别正常[牙合]儿童的咬合重心均位于磨牙区,最大咬合压强点有7例儿童仅位于第一恒磨牙区,有10例儿童在乳磨牙区和第一恒磨牙区均存在,有3例儿童仅位于乳磨牙区。结论:混合牙列个别正常[牙合]儿童在牙尖交错位时的最大咬合力、咬合接触面积、平均咬合压强、最大咬合压强双侧对称性良好;最大咬合力、咬合接触面积存在性别差异,男童大于女童;最大咬合力与咬合接触面积呈正相关。
文摘在基于增强现实装配引导的复杂零/部件装配场景中,由于手部对零/部件的遮挡,导致零件位姿解算时产生较大的误差,甚至造成求解失败。目前针对手工装配零件的位姿估计算法在解决零件遮挡问题时没有考虑手部信息,使得位姿估计精度难以满足增强装配实际应用的要求。针对上述问题,提出了融合手部姿态的零件6D位姿估计算法,即HandICG算法。该算法将手部的姿态信息与迭代对应几何(Iterative Corresponding Geometry,ICG)算法进行融合,当发生手部遮挡时,将手部的姿态信息应用到零件姿态的求解中,从而显著提高手部遮挡情况下零件位姿估计的精度,实验表明,平均模型点距离(Average Distance of Model points,ADD)相关评价指标达到74.73%,是ICG算法的2.61倍。该算法显著提升了增强装配场景中零件位姿解算的准确性和鲁棒性。
