传动直丝弓技术矫治壮族青少年双颌前突畸形的疗效评价

目的:探讨传动直丝弓技术矫治广西壮族青少年双颌前突畸形的临床效果。方法:对24例双颌前突畸形的广西壮族青少年采用传动直丝弓技术进行矫治,24例患者均拔除4颗第一前磨牙。对矫治前后的X线头颅侧位定位片进行相关项目的测量并统计分析其变化。结果:矫治后上下切牙明显内收,U1-L1角增加26.1°(P<0.001);软组织侧貌明显改善,接近直面型,鼻唇角(NLA)平均增加21.71°,Z角平均增加7.33°,治疗前后变化均有统计学意义(P<0.001)。结论:双颌前突畸形的广西壮族青少年经传动直丝弓技术矫治后,可以获得良好的牙合关系及较为理想的侧貌。     

舌侧活动翼矫治器治疗双颌前突的临床研究

目的:研究舌侧活动翼矫治技术治疗均角型双颌前突的临床疗效。方法:选取均角型双颌前突患者31例(29°相似文献   

上颌扩弓前方牵引辅助直丝弓矫治技术对恒牙早期骨性Ⅲ类错(牙合)畸形的矫治效果研究

目的:探究上颌扩弓前方牵引辅助直丝弓矫治技术对恒牙早期骨性Ⅲ类错(牙合)畸形患者的矫治效果。方法:选择河北省文安县医院2012年6月-2017年6月收治的12例恒牙早期骨性安氏Ⅲ类错(牙合)畸形患者为研究对象。所有患者采用上颌扩弓前方牵引辅助直丝弓矫治技术治疗,矫治前后拍摄头颅定位侧位片,测量分析其头颅定位侧位片并对所有患者的临床矫治效果进行比较。结果:12例患者治疗后,SNA角、ANB角、U1/SN、SN/MP、OP/FH、Y轴角、上唇突角、下唇倾角、下唇至审美平面均大于治疗前;SNB角、L1-MP、U1-NA、L1-NB、鼻唇角、下唇颏突角、上唇至审美平面均小于治疗前。治疗后患者的软组织侧貌明显改善,前牙覆(牙合)覆盖正常,磨牙中性关系,比较有显著性差异,具有统计学意义(P0.05)。结论:上颌扩弓前方牵引辅助直丝弓矫治技术矫治恒牙早期骨性Ⅲ类错(牙合)畸形效果显著,能够使患者的软硬组织得到显著改善,便于纠正牙性、骨性关系。     

微种植体支抗矫治成人轻中度骨性前突的临床应用

目的:探讨自攻型微种植体支抗在骨性前突患者矫治中的临床应用效果。方法:选择骨性双颌前突患者22例,矫治设计拔除上下颌双侧第一前磨牙,利用自攻型微种植体支抗作为强支抗整体内收前牙。种植体支抗植入第一磨牙颊侧牙槽骨近中或远中位置,植入后施以100g的矫治力关闭间隙。治疗前后均拍摄头颅侧位片进行测量分析。结果:微种植体支抗均保持稳定,前牙内收明显,面型得到改善,患者对矫治效果基本满意。头影测量分析显示:U1-NA角、U1-NA距、L1-NB角、L1-NB距、上唇突度、下唇突度及面型角明显减小,治疗前后差异均具有统计学意义(P0.05),而SNA、SNB、ANB、U6-PP、MP/FH治疗前后差异无统计学意义(P0.05)。结论:微种植体支抗作为强支抗系统可以有效地改善成人轻中度骨性前突畸形。     

两种不同矫治器结合微种植体矫治上颌前突临床研究

目的:临床使用自锁托槽和直丝弓矫治器结合微种植体支抗,矫治上颌前突错牙合畸形的疗效比较。方法:选取32例上颌前突错牙合畸形患者,分别使用自锁托槽矫治器结合微种植体支抗(实验组,16例)和传统直丝弓托槽矫治器结合微种植体支抗(对照组,16例)。记录并分析两组患者排齐、关闭间隙和总的治疗时间;测量两组患者尖牙牙根长度和牙槽骨高度,以及头影测量项目,并对治疗前、后的变化进行比较分析。结果:实验组总疗程平均(19.6±5.39)个月,短于对照组的(25.7±5.76)个月,差异有统计学意义(P0.05);两组尖牙牙根长度和牙槽骨高度治疗前后变化比较,差异均无统计学意义(P0.05);32例牙弓突度均得到改善,实验组治疗后U1-SN角、U1-X(mm)、U1-Y(mm)、A-Y(mm)、UL-Y(mm)均显著低于对照组,两组比较差异有统计学意义(P0.05)。结论:自锁托槽矫治器结合微种植体支抗矫治上颌前突拔牙患者,能显著缩短拔牙间隙关闭的时间,缩短总疗程,前牙覆牙合覆盖的变化显著,侧貌改善明显,且尖牙牙根和牙槽骨无明显吸收。     

Activator与MBT直丝弓矫治器双期矫治安氏Ⅱ~1类错牙合畸形的临床应用

目的:探讨Activator矫治器与滑动直丝弓矫治器(MBT appliance)双期矫治安氏Ⅱ1类错牙合畸形的临床效果。方法:选择17例混合牙列期以下颌后缩为主的安氏Ⅱ1类错牙合患者,Ⅰ期采用Activator矫治器,Ⅱ期采用MBT直丝弓矫治器。每位患者均拍摄矫治前、后头颅定位侧位片、曲面断层片,以X线头影测量方法评价疗效。结果:硬组织主要测量项目的变化:SNB角增加2.9°,ANB角减小2.9°,下中切牙切缘至鼻根点与下齿槽座点连线的垂直距离L1-NB(mm)减小3.5°,下颌体长度Go-Gn(mm)增加3.0mm,前面高N-Me(mm)增加5.6mm;软组织主要测量项目的变化:鼻唇角Cm-Sn-UL增大7.2°,颏唇沟角Li B’Pg’增大12.1°,面凸角Ns-Sn-Pos减小2.0°,上唇-审美平面Ls-E(mm)减小1.6mm,下唇-审美平面Li-E(mm)增大2.1mm。治疗结束时磨牙和尖牙均为安氏Ⅰ类关系,前牙覆盖明显减小,侧面型有所改善。结论:安氏Ⅱ1类错牙合患者在替牙期采用双期矫治能改善其面部侧貌,显著改善上下颌骨骨性关系。Activator能有效促进下颌生长。     

Twin-block矫治器治疗下颌后缩对鼻唇颏协调性的影响

目的:研究Twin-block矫治器治疗安氏Ⅱ1类下颌后缩患者对鼻唇颏协调性的影响。方法:选择自然生长和使用Twin-block矫治成功的40例骨性Ⅱ类错患者为研究对象,将其分为对照组和Twin-block组,每组均为20例患者。在正畸治疗前后拍摄X线头颅定位侧位片,对治疗前后X线头影测量值进行比较。结果:治疗组上唇审美平面距、下唇审美平面距、上唇突角、上下唇突角、颏沟倾角、上唇颏突角、软组织面角减小;上唇倾角、下唇倾角、鼻唇角、颏唇沟角、Z角、面突角、软组织面高、软组织下面高增大,与对照组比较均具有统计学意义(P<0.05)。结论:Twin-block矫治器可显著减小上下唇突度,促进面下1/3高度的生长,在一定程度上恢复了鼻、唇、颏之间的协调性,使侧貌轮廓变得自然舒缓,软组织侧貌趋于直面型。     

传动直丝弓技术矫治安氏Ⅱ类错的临床初步应用

目的：通过观察传动直丝弓技术矫治的俺氏Ⅱ类错患者软组织侧貌、牙的特征性改变,探讨该技术的矫治要点。方法：应用传动直丝弓技术矫治13例（女8例,男5例）安氏Ⅱ类错双颌或上颌前突患者,平均年龄13.2岁。所有患者均拔除4颗第一前磨牙,按照传动直丝弓技术矫治程序进行矫治。结果：与矫治前相比,矫治后上、下切牙显著内收,软组织侧貌改善明显。结论：传动直丝弓矫治器利用口内支抗、细丝轻力,快速倾斜移动牙齿,准确转矩并正轴的方法,可有效矫治安氏Ⅱ类错双颌或上颌前突患者。     

传动直丝弓技术矫治安氏Ⅱ类错(牙合)的临床初步应用

目的:通过观察传动直丝弓技术矫治的俺氏Ⅱ类错(牙合)患者软组织侧貌、牙的特征性改变,探讨该技术的矫治要点.方法:应用传动直丝弓技术矫治13例(女8例,男5例)安氏Ⅱ类错(牙合)双颌或上颌前突患者,平均年龄1 3.2岁.所有患者均拔除4颗第一前磨牙,按照传动直丝弓技术矫治程序进行矫治.结果:与矫治前相比,矫治后上、下切牙显著内收,软组织侧貌改善明显.结论:传动直丝弓矫治器利用口内支抗、细丝轻力,快速倾斜移动牙齿,准确转矩并正轴的方法,可有效矫治安氏Ⅱ类错(牙合)双颌或上颌前突患者.     

微种植体支抗在上下颌不对称拔牙矫正中的应用

目的:评价微种植体支抗在上下颌不对称拔牙矫正病例中的临床应用效果。方法:选择30例年龄13～20岁,安氏Ⅱ类,严重拥挤需上下颌不对称拔牙矫治的错牙合畸形患者,随机分成两组。实验组使用微种植体支抗辅助进行矫治,对照组仅使用常规直丝弓矫治技术,通过治疗前后模型和头颅侧位片测量进行分析,比较两组病例矫治前后的临床效果。结果:30例错牙合畸形患者均解除拥挤,排齐牙齿,但实验组上颌切牙的后移距离大于对照组,而支抗牙(下颌第二磨牙)的前移距离却小于对照组(P<0.001)。结论:微种植体支抗在上下颌不对称拔牙矫正病例中不仅能更好地内收前牙、改善侧貌,而且可以更加有效地防止支抗丧失,值得临床推广。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.