家兔阴茎皮肤感觉脊神经来源的电生理研究

目的:探讨家兔阴茎感觉神经来源。方法:健康成年雄性新西兰白兔12只,随机均分为两组:每组6只,A组在左侧脊神经上记录,B组在右侧脊神经上记录。对家兔阴茎施加不同大小的机械刺激,用神经单纤维记录技术,在同侧S1~S4脊神经上记录单纤维放电。结果:通过对家兔阴茎施加各种不同机械刺激,在同侧S2~S3脊神经上能记录到放电,S1、S4脊神经上未能记录到放电。左侧脊神经放电纤维数量分别为:S2:39.67±3.14,S3:21.00±2.19;右侧脊神经放电纤维数量分别为:S2:40.00±3.16,S3:19.67±2.58,左右侧差异无显著性(P>0.05)。结论:家兔阴茎皮肤感觉来源于S2~S3脊神经。     

天鹅型形状记忆合金接骨器对实验性骨折愈合中皮质骨胶原构筑与力学性能的影响

目的探讨天鹅型形状记忆合金接骨器(SMC)对实验性骨折愈合中皮质骨胶原构筑和力学性能的影响。方法45只新西兰大白兔双侧肱骨干截骨后,随机选取一侧用SMC固定,另一侧用4孔动力加压接骨板(DCP)固定;分别于术后2、4、8、16、32周各处死9只动物取材,4只用于扫描电镜观察固定段皮质骨胶原构筑的变化,5只用于骨干扭转生物力学性能的测定。结果SMC组在整个固定过程中,皮质骨结构与正常对照组相比无明显变化。而DCP组术后4周,胶原排列出现稀疏,局部有小吸收陷窝形成;术后8周时,胶原排列紊乱,且有多个吸收腔形成;术后16周时,胶原纤维出现中断;术后32周,骨质疏松化更加明显。术后2周时,两组肱骨骨断端尚未形成骨性连接,不能测得力学数据。术后4～32周,SMC组骨折愈合部位的扭转刚度明显优于DCP组,差异有统计学意义(F= 5．468,P＜0．05)。术后16周,SMC组骨折愈合部位的力学性能即接近正常,而DCP组术后16周扭转刚度即不再增加。结论SMC具有材料特性和几何构型上的优势,对骨干不产生应力遮挡效应,而且能有效防止骨质疏松的发生,使骨的力学性能尽早恢复。     

不同形态牙本质肩领与牙根抗力的实验研究

目的:研究5种不同形态牙本质肩领对牙根抗力的影响。方法:25颗完整离体上颌中切牙随机分成5组,按实验设计制备5种不同形态牙本质肩领:即360°环形肩领组、180°唇侧肩领组、180°腭侧肩领组、180°远中肩领组和无肩领组。所有离体牙均采用预成石英纤维桩、复合树脂核、镍铬合金全冠修复。试件于铸造全冠颈缘线下2mm包埋在自凝塑料中,电子万能试验机以与牙长轴成130°,加载速度为1.0mm/min,于样本牙腭面切端下2mm处加载,记录折裂载荷及牙体断裂的位置和方式,进行统计学分析。结果:5组样本牙抗折力值顺序为环形肩领组、腭侧肩领组远中肩领组唇侧肩领组无肩领组,前两组样本牙根抗折力显著高于后两组,差异有显著性(P0.01)。所有样本中可修复性折裂占92%。结论:残根龈上剩余牙本质的位置能影响桩核冠修复后的牙根抗力。     

改良式微推出试验评价化学处理玻璃纤维桩表面后与树脂水门汀的粘接强度

目的:建立一种改良式微推出方式测试玻璃纤维桩表面经35%磷酸+硅烷偶联剂处理后与树脂水门汀的粘接强度,探讨此种测试模式评价玻璃纤维桩与树脂水门汀粘接强度的价值。方法:先将40支玻璃纤维桩随机分成2大组,每组20支,组1为磷酸+硅烷化组,组2为对照组。再将每一大组随机分为M(改良)和T(传统)两个小组,每组10支,分别用改良式微推出试验和传统微推出试验测定纤维桩与树脂水门汀的粘接强度并观察破坏模式。结果:组1M(磷酸+硅烷化组-改良)微推出粘接强度为(18.85±1.42) MPa,组1T(磷酸+硅烷化组-传统)为(19.39±1.35) MPa,组2M(对照组-改良)为(11.26±1.57)MPa,组2T(对照组-传统)为(11.27±1.83)MPa,在改良组和传统组中,磷酸+硅烷化组粘接强度值均显著高于对照组(P<0.01),且改良组中断裂模式100%为桩/树脂界面破坏,相比传统组的65.7%,更加集中体现界面粘接强度的变化。结论:相较于传统组,改良组微推出试验能更有效地评价纤维桩与树脂水门汀之间的粘接强度,且35%磷酸+硅烷化处理玻璃纤维桩表面可以更有效地提高其与树脂水门汀的粘接强度。     

Secondary Bone Grafting of Alveolar Clefts: A Surgical/Orthodontic Treatment Enabling a Non-prosthodontic Rehabilitation in Cleft Lip and Palate Patients

A procedure combining grafting of cancellous bone to the residual cleft of the primary palate with subsequent orthodontic movement of teeth into the former cleft area is described. The preliminary results from the first 80 patients (89 clefts) are presented. The age of the patients at the bone grafting ranged from 8 to 18 years, and the observation time from 17 to 44 months. The results have been assessed 1) on the basis of dental radiographs and 2) clinically, by the response of the grafted area to the orthodontic movement of adjacent teeth. In 69 clefts in which the cleft side canine had been brought into its final position at the time of evaluation, the height of the interal-veolar septum was assessed to be approximately normal in 38% and slightly less than normal in 44%. A septum of insufficient height (less than 3/4 of the normal) had formed in 5 clefts (7%). Even in these cases, the main objects of the operation were fulfilled: The maxillary segments were stabilized, the teeth adjacent to the cleft had better bone support, and the gap in the dental arch could be closed orthodontically in four of the five clefts. Failures, i.e. no continuous bone bridge across the alveolar cleft, were recorded in 8 instances (9%) of the total material. When failures were disregarded, the gap in the dental arch was closed orthodontically in 90%, while prosthodontic closure was deemed necessary in 10% of the cases. Optimal results were obtained when bone grafting was performed prior to the full eruption of the cleft side canine. In this situation, the known potential of an erupting tooth to induce alveolar bone generation proved to be of great advantage. By deliberately guiding the erupting canine through the grafted area close to the incisor, a nearly normal interalveolar septum was formed, and the gap in the dental arch was closed orthodontically in 23 out of 26 clefts. When fissural teeth were present, they were in most cases integrated in the dental arch. Approximate incisor symmetry could thus be obtained. In the remaining 20 clefts, the ipsilateral canine had not reached its final position at the time of evaluation, and the end results could not be assessed. However, bone formation in the defect was good in 19 of the 20 clefts, and a fully satisfactory result is expected in the majority of these cases. Further advantages were obtained by this procedure: 1) The maxillary segments were stabilized, particularly important in bilateral clefts in which the premaxilla was movable. 2) Oronasal fistulae were effectively closed and mucosal recesses eliminated. 3) The grafted bone provided support for the receded alar base, reducing the nasal asymmetry and improving the facial contour. 4) The postoperative orthodontic treatment could be brought to an end at approximately the same age as for patients with a non-cleft malocclusion. The only significant complication in this series was infection of the grafted area, causing loss of the bone grafts in two cases, and possibly contributing to the failure in some other patients. The experience gained with this treatment permits the conclusion that a full osseous and dental rehabilitation can be achieved in the great majority of patients with cleft lip and palate without any prosthodontic reconstructive work.     

数据驱动的三叉神经纤维束自动分割算法

目前三叉神经的纤维跟踪成像过程中普遍存在人工依赖性问题,主要包括人工绘制感兴趣区域(ROI)及手动筛选目标纤维束,导致结果的不确定性和数据误差。针对此类问题,提出一种数据驱动的三叉神经纤维自动分割算法。利用多组大脑样本的纤维数据,建立数据驱动的纤维聚类图谱,实现新样本纤维数据的自动分割,直接得到三叉神经纤维束。在实验中,选择25组青年健康人的数据作为样本数据。首先,利用FSL软件分割工具提取脑干作为ROI,进行确定性纤维跟踪。其次,通过对20组纤维数据进行多样本配准和谱聚类,创建数据驱动的纤维聚类图谱。根据三叉神经细小的特点,在建立纤维图谱过程中,通过对脑干纤维束进行二次分类来标注三叉神经纤维束。最后,选择5组青年健康人的新样本数据,将其脑干纤维数据应用纤维图谱自动分割得到三叉神经纤维束,并计算同一样本数据的自动分割结果与手动分割结果之间的加权Dice系数。结果显示,所提出的方法成功分割5组数据的三叉神经纤维束,而传统人工方法成功识别4组三叉神经纤维束,两者结果之间的加权Dice系数分别为0.865,0.939,0.824,0.942。该方法可以有效避免人为因素的影响,提高神经外科医生...     

Radiation-Free Thoracic Endovascular Aneurysm Repair with Fiberoptic and Electromagnetic Guidance: A Phantom Study

PurposeTo evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom.Materials and MethodsAn anthropomorphic phantom was manufactured based on computed tomography (CT) angiography data from a patient. An aortic stent graft application system was equipped with a fiber Bragg gratings and 3 electromagnetic sensors. The stent graft was navigated in the phantom by 3 interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and CT angiography (before and after the intervention). Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent graft application system and the tip/end of the stent graft.ResultsThe procedure resulted in technical success with a mean error below 3 mm for the entire application system and <2 mm for the position of the tip of the stent graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on par with comparable, routinely used stent graft application systems.ConclusionsThe study demonstrates successful stent graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.     

石英纤维桩核烤瓷冠修复残根残冠的临床疗效评价

目的:研究和评价石英纤维桩在修复前后残根、残冠的效果评价和临床应用体会.方法:应用石英纤维桩选取169例患者182颗患牙,分为两组,一组为前牙残冠组,另一组为后牙残冠组,都应用石英纤维桩复合树脂核和金属烤瓷冠修复.观察修复6个月～1年、2年,3年修复成功率并进行比较.结果:1年成功率前后牙残冠修复均为成功率100%;两年前牙修复残冠的成功率99.35%,后牙残冠修复成功率100%;3年前牙98.02%,后牙92.86%.合计成功176例,失败6例,成功率97%.结论:石英纤维桩在残根,残冠保留中有良好的临床修复效果,生物相容性好,优良的临床美学效果,柔韧性强,抗绕曲强度大,增加根管壁的强度.     

纤维桩核修复后牙残冠临床疗效观察

目的:观察纤维桩核修复后牙残冠的疗效。方法:应用瑞士康特公司生产的Par a Pos t FI BER LUX玻璃纤维桩核材料成型后牙残冠桩核,辅以氧化锆全瓷冠修复外冠,86例(117颗)后牙于修复后6、12、18、24个月随访评估临床疗效。结果:117颗患牙在修复后随访观察期间,2颗修复体发生崩瓷现象,1颗修复牙并发牙龈炎,2颗患牙发生修复体外冠脱落,1颗修复体发生食物嵌塞;所有修复牙未发现根折、纤维桩核脱落、纤维桩折断及慢性根尖周炎等严重并发症。结论:应用纤维桩核修复后牙残冠能获得良好的近期临床效果。     

Interfacial shear strength of bioactive‐coated carbon fiber reinforced polyetheretherketone after in vivo implantation

Despite the excellent osseointegration of carbon‐fiber‐reinforced polyetheretherketone (CFR/PEEK) with a surface hydroxyapatite (HA) coating, the bone‐implant interfacial shear strength of HA‐coated CFR/PEEK after osseointegration is unclear. We examined the interfacial shear strength of HA‐coated CFR/PEEK implants after in vivo implantation in a rabbit femur‐implant pull‐out test model. HA coating was performed by a newly developed method. Uncoated CFR/PEEK, HA‐coated blasted titanium alloy, and uncoated blasted titanium alloy were used as control implants. The implants were inserted into drilled femoral cortex, and pull‐out tests were conducted after 6 and 12 weeks of implantation to determine maximum interfacial shear strength. The HA‐coated CFR/PEEK (15.7 ± 4.5 MPa) and HA‐coated titanium alloy (14.1 ± 6.0 MPa) exhibited significantly larger interfacial shear strengths than the uncoated CFR/PEEK (7.7 ± 1.8 MPa) and the uncoated titanium alloy (7.8 ± 2.1 MPa) at 6 weeks. At 12 weeks, only the uncoated CFR/PEEK (8.3 ± 3.0 MPa) exhibited a significantly smaller interfacial shear strength, as compared to the HA‐coated CFR/PEEK (17.4 ± 3.6 MPa), HA‐coated titanium alloy (14.2 ± 4.8 MPa), and uncoated titanium alloy (15.0 ± 2.6 MPa). Surface analysis of the removed implants revealed detachment of the HA layer in both the HA‐coated CFR/PEEK and titanium alloy implants. The proposed novel HA coating method of CFR/PEEK significantly increased interfacial shear strength between bone and CFR/PEEK. The achieved interfacial shear strength of the HA‐coated CFR/PEEK implant is of the same level as that of grit‐blasted titanium alloy with HA. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1618–1625, 2012