安氏Ⅰ类错(牙合)中第一磨牙缺失矫治设计的探讨

目的：探讨第一磨牙缺失在Ⅰ类错[牙合]畸形中的矫治设计。方法：选择安氏Ⅰ类错[牙合]畸形中第一磨牙缺失患者15例，根据牙弓的拥挤程度，面型突度，第三磨牙位置等进行分析，选择拔牙矫治、非拔牙矫治及修复治疗的方法。结果：15例患者中11例采用拔牙矫治，2例采用非拔牙矫治，2例采用修复治疗。时间最长22个月，最短12个月，平均16个月。结论：第一磨牙缺失的患者在Ⅰ类错牙舍畸形中的拔牙模式有别于常规，要根据患者牙弓的拥挤程度，面型突度及有无第三磨牙等情况选择治疗计划和有利于缩短疗程的矫治方法。     

下切牙先天缺失错畸形的临床治疗

目的：探讨下切牙先天缺失错畸形的临床治疗方法。方法：选择下切牙先天缺失的错畸形患者22例,对缺牙部位、缺牙数目、错类型、矫治方法等进行分析。结果：10例单颗下切牙先天缺失患者中,有5例采用减数矫治,2例采用减径矫治,3例采用正畸结合修复的方法进行治疗。12例两颗下切牙先天缺失患者中,有8例采用减数矫治,4例采用正畸结合修复的方法进行治疗。治疗后所有患者上下牙列Bolton指数协调,咬合关系达到正常,侧貌外形得到改善。结论：对于下切牙先天缺失的错畸形,应该根据患者的年龄、面型、牙弓突度、下切牙缺失部位、数目、中线及错畸形等情况,在Bolton指数的指导下,制定不同的治疗计划,以达到良好的咬合关系和美观效果。     

应用微种植体支抗不拔牙矫治重度牙列拥挤

目的：探讨采用微种植体非拔牙矫治重度牙列拥挤的临床效果及特点。方法：患者12例,均为安氏II类错,面型基本正常,上牙弓拥挤度〉8mm,在上颌颊侧牙槽骨共植入24枚微种植体,将Ni-Ti螺旋推簧置于上颌第二前磨牙与上颌第一磨牙之间,推磨牙远移,术前后行X线头影测量和模型分析。结果：12例重度拥挤患者治疗后均达到满意效果,牙列整齐,咬合关系正常,面型良好,治疗前后SNA、SNB、U1-NA未见明显变化（P〉0.05）,上颌第一磨牙平均远中移动距离5.48mm（P〈0.01）,其颊向移动距离及旋转角度无统计学意义。结论：应用微种植体推磨牙向远中能成功的非拔牙矫治重度牙列拥挤,种植体支抗在磨牙远移过程中,发挥了绝对强支抗作用。     

FRⅢ矫治功能性Ⅲ类错畸形的颌面分析

目的:探讨FrankelⅢ功能矫治器(Frankel functional regulator Ⅲ appliance,FRⅢ)矫治功能性Ⅲ类错畸形前后颌骨软组织侧貌头影测量值的变化。方法:选择乳牙期、替牙期功能性Ⅲ类错患者20例(男9例,女11例),年龄6～11岁,平均9.8岁,面型为直面型或轻度凹面型,前牙反,第一磨牙为近中关系,下颌可后退至切对切,上下前牙排列整齐,应用FRⅢ矫治,治疗前后拍X线头颅侧位定位片并测量数据,采用配对t检验统计学分析。结果:功能性Ⅲ类错畸形经FRⅢ矫治6个月左右,临床上患儿反矫正、侧貌发生改变,SNB减小、ANB增加、前下面高增加、IMPA减小、面凸度增加、覆盖增加有显著性差异。唇形改变:上唇突度增大、下唇突度减小,上唇倾斜度减小、下唇倾斜度减小有显著性统计学意义。结论:表明FRⅢ矫治功能性Ⅲ类错畸形能引起颌骨及软组织侧貌的改变,FRⅢ是治疗功能性Ⅲ类错畸形的有效方法。     

骨性Ⅲ类错非拔牙矫治后牙弓与基骨弓变化的分析研究

目的:了解恒牙列骨性Ⅲ类错非拔牙矫治后牙弓与基骨弓形态的变化。方法:23例恒牙列骨性Ⅲ类错非拔牙矫治患者,收集矫治前后记存模型,测量矫治前后上下颌牙弓长度、基骨弓长度,尖牙区、第一、二前磨牙区,第一磨牙区的牙弓宽度、基骨弓宽度,比较矫治前后牙弓、基骨弓各测量值的变化及两者间的相关性。结果:(1)矫治后上颌牙弓前段长度增加,上颌尖牙间、第一、二前磨牙间牙弓宽度减小;下颌尖牙间牙弓宽度减小、第一磨牙间牙弓宽度增加;矫治前后差异有统计学意义(P0.05);(2)矫治后上颌基骨弓长度增加,下颌基骨弓长度减小,矫治前后差异有统计学意义(P0.05);(3)矫治后上下颌牙弓长度、宽度的变化量与对应的基骨弓长度、宽度的变化量呈正相关,尤以下颌尖牙区、上下颌第一磨牙区明显。结论:恒牙列骨性Ⅲ类错非拔牙正畸掩饰性矫治后牙弓代偿性变化可引起相应区域基骨弓的顺应性改建,利于骨性Ⅲ类错单纯正畸掩饰性治疗及稳定疗效。     

自攻型微钛钉种植体支抗在成人骨性安氏Ⅱ类错矫治中的应用

成人骨性安氏Ⅱ类错畸形多表现为牙弓前突、开唇露齿的突面型,严重影响颜面美观,患者及家属要求治疗的愿望迫切。由于年龄及生长发育的关系,早期矫治的方法不适于成人,手术治疗的方法又不能被大多数患者接受,如何最大限度地内收前突的牙弓,改善突面型来达到代偿性掩饰治疗是固定矫治的关键,因此支抗的控制在矫治中显得尤为重要。本文在9例成人骨性安氏Ⅱ类错畸形的矫治中使用自攻型微钛钉种植体提供强支抗内收前牙,取得了     

安氏I类错牙合拔牙与非拔牙矫治前后牙弓宽度变化的对比研究

目的:通过对拔牙组和非拔牙组恒牙期安氏I类错牙合畸形患者矫治前后的模型进行测量,分析拔牙组和非拔牙组病例治疗前后牙弓宽度的变化。方法:随机选择恒牙牙合患者40例,其中20例接受了拔牙矫治,均拔除4个第一前磨牙,20例接受了非拔牙矫治,分别在矫治前后的上下颌模型上第一磨牙近中颊尖点、尖牙牙尖点做标记,测量磨牙和尖牙间的牙弓宽度,进行方差分析。结果:拔牙组矫治前后比较上下颌尖牙间宽度均增加,差异有统计学意义(P0.05);拔牙组磨牙矫治前后牙弓宽度变化无统计学差异(P0.05);非拔牙组矫治前后上颌第一磨牙间宽度增加,差异有统计学意义(P0.05);非拔牙组矫治前后上下颌尖牙间宽度、下颌第一磨牙间宽度变化无统计学差异(P0.05)。结论:与非拔牙矫治相比,拔牙矫治并不会引起牙弓的缩窄。     

摆式矫治器远移上颌第一磨牙对上颌牙弓形态变化的影响

目的:研究摆式矫治器远中移动上颌第一磨牙对上颌牙弓形态的影响。方法:选择混合牙列或恒牙列早期的牙源性安氏Ⅱ类错伴发上颌牙列轻中度拥挤的病例16例,应用摆式矫治器远中移动上颌第一磨牙至上下颌第一磨牙呈中性偏近中关系,测量矫治前后模型,对其结果进行配对t检验。结果:①远中移动时间平均(5.1±1.4)月,拥挤度平均减少(8.40±2.01)mm;前牙覆盖较矫治前平均增加0.43mm;前牙覆平均减小0.32mm②上颌尖牙、前磨牙、第一磨牙间牙弓宽度有不同程度的增加,其中以前磨牙间增加最多,第一磨牙次之,尖牙间增加最少;③上颌第一、第二前磨牙、第一磨牙间牙槽弓、基骨弓宽度均有增加,第一磨牙间增加最多,前磨牙次之,上颌尖牙间增加最少;④牙弓长度方面:牙弓前段无明显改变,仅增加0.10mm(P>0.05),而牙弓后段长度与矫治前相比增加了3.12mm(P<0.001),上颌的牙槽弓长度与基骨弓长度分别增加了3.23mm(P<0.01),3.50mm(P<0.01)。结论:①应用摆式矫治器远中移动上颌第一磨牙使上颌牙槽弓及基骨有一定的扩宽趋势,有利于牙弓前段拥挤的解除及安氏Ⅱ类错的矫治,进而为非拔牙矫治提供有利依据;②远移上颌第一磨牙同时伴随少量的支抗丧失,临床应用中应予注意。     

Pancherz分析法评价不拔牙方法治疗发育高峰期安氏Ⅱ类1分类错畸形的临床疗效

目的:评价不拔牙方法治疗生长发育高峰期安氏Ⅱ类1分类错畸形的临床疗效。方法:对22例10~14岁安氏Ⅱ类1分类错患者进行快速扩弓,运用直丝弓矫治技术完成不拔牙矫治。采取Pancherz二类错矫正分析方法结合传统测量项目分析治疗前后头颅侧位片,用SPSS 17.0统计软件对18项测量数据进行统计分析。结果:患者治疗后,下颌骨发生明显前移,SNB角平均增加了2.30°,ANB角平均减小2.14°。下颌骨长度平均增加了2.67m,覆盖减小5.95mm,上中切牙明显内收。磨牙关系均调整为中性关系,下颌平面未发生明显旋转。结论:上下联合扩弓结合直丝弓矫治技术,能保留全口牙列,改善下颌后缩面型,是治疗轻中度拥挤的安氏Ⅱ类1分类错畸形的有效方法之一。     

拔牙矫治的临床治疗分析

目的:分析拔牙矫治在临床治疗中的应用情况,了解拔牙位置与错牙合畸形类型的关系。方法:随机抽取临床病例312例,所有病例均为恒牙期错牙合畸形,用固定矫治器矫治,把每个病例的各项资料输入计算机,进行统计分析。结果:Ⅱ类错牙合拔牙矫治比率最高。随着拥挤度、上前牙突度的增加,拔牙的百分比也加大。结论:牙齿拥挤度越大,上前牙越突,拔牙率越高,越倾向于拔除第一前磨牙。     

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.