龈壁设计对应用嵌体修复后牙体组织应力改变的影响

目的:建立嵌体修复后牙体三维有限元模型,应用不同的龈壁设计,观察相关力学参数变化。方法:①下颌第一磨牙标本来源于佳木斯大学解剖学教研室,标本要求:磨耗少,其牙冠长、宽、高接近正常下颌第一磨牙的均值。②建立有限元模型:用蜡块将牙齿固定,使扫描尽可能与牙体长轴垂直,扫描至牙颈部。根据各层图上建立的平面坐标,设颊舌向为X轴,近远中向为Y轴,龈向为Z轴。按照有限元单元划分的原则和计算机分析软件的要求,对各个断层的解剖轮廓进行边界节点选择和单元网格划分。根据组织结构特点,进行节点调整。通过人机交互,输入每个节点的坐标和组成单元的节点,分层建立由六面体单元所构成的三维有限元模型。③计算:在后牙邻洞应用不同的龈壁设计,于面上施加一竖直向下的力,大小为170N,方向与Z轴相同,通过有限元分析计算获取应力分布图像和应力数据。结果:①龈壁高度的增加,使牙釉质应力减少(0.1～0.27MPa),对牙本质无明显影响。②龈壁宽度的增加,使牙釉质应力增加(0.1～0.27MPa)、牙本质应力亦增加(0.01～0.03MPa)。③龈壁角度的增加,牙釉质和牙本质应力无明显改变。结论:Ⅱ类洞嵌体设计时,龈壁高度增加,宽度尽量减小有利于减小修复后牙体的应力。龈壁角度的有无对牙体应力无影响。     

固定修复后垂直型食物嵌塞76例原因分析

目的分析固定修复后垂直型食物嵌塞的原因,以期对临床固定修复有所指导。方法对固定修复术后出现垂直型食物嵌塞的81个邻接区进行统计观察,分析食物嵌塞的原因。同时对100个未戴入的与邻牙有接触关系的固定修复体的解剖外形进行观察统计。结果 81个邻接区中,66个存在解剖形态不良,28个存在邻接触不良,12个对颌存在充填式牙尖,5个存在邻牙或患牙松动。100个未戴入的修复体中55个存在解剖形态不良。结论固定修复后垂直型食物嵌塞原因常几种原因并存,其中解剖形态不良是最常见的因素。加工厂生产的修复体常存在解剖形态不良,需要临床医师进行调磨修整。     

不同人群对露龈微笑的审美认知研究

目的：探讨不同人群对露龈微笑的审美认知及可接受的微笑露龈范围。方法采集44名年轻女性标准正面微笑像,随机选取13位口腔医师及23位普通人,分别对44副微笑像进行VAS审美打分。对得分最低的微笑像进行上唇下降、下唇上升、上下唇聚合及上唇增高等计算机处理,并进行再次打分。结果口腔医师认为露龈1 mm最美观,普通人认为露龈0 mm最美观。仅作上唇下降处理时,医师对微笑审美垂直向变化的敏感度（发现嘴唇变化的最小变化幅度）平均值为1．54 mm,普通人群则为2．0 mm。微笑时牙龈暴露量的可接受范围医师组为0．54～2．23 mm,普通人群组为0．13～2．35 mm。在一定的露龈范围内,唇红高度和形态对微笑具有更大影响。结论口腔医师与普通人对露龈微笑的审美认知基本一致。但就露龈微笑的接受程度方面,口腔专业医师较普通人群更为苛刻,且对其变化更为敏感。     

豆瓣成型片在前牙邻面龋充填成形中的临床应用

目的 探究豆瓣成型片在前牙邻面龋充填成形的临床应用意义及效果评价.方法 30例前牙邻面龋患者随机分成2组,共60颗患牙,试验组采用豆瓣成型片进行邻面龋坏修复,对照组采用聚酯塑料薄片进行修复.修复后1个月、6个月、12个月,对比两组患牙邻接关系、牙线通过阻力、食物嵌塞、继发龋发生率和牙龈指数.结果 充填后1个月、6个月和...     

烤瓷冠基牙折断的桩核再修复疗效观察

1.1 对象 选择病例标准：基牙折断部位至少位于龈上2mm，基牙边缘清晰．牙龈附着正常无炎症．烤瓷冠完整无破损．边缘与基牙边缘密合度良好．邻而与邻牙邻接关系正常。选择2000-02～2004-05来我院以烤瓷冠基牙折断为主诉患14例14颗．年龄25～53岁，修复时间7个月～6a。其中中印牙7例．侧切牙3例，尖牙1例．前磨牙3例。临床检查可见基牙冠部断于烤瓷冠内．X线片显示根管治疗完善8例．根管欠填4例．活髓牙2例。     

前牙根管制备引起面部皮下气肿1例

患者,女,28岁.因外伤造成前牙冠折,于2002年2月来我院就诊,经口腔内科完善的根管治疗后,在我院行左、右上中切牙桩冠修复治疗.检查:右上中切牙冠折,唇侧达龈下1mm,腭侧与龈缘平齐;左上中切牙冠折,唇侧位于龈上2mm,腭侧斜行壁裂达根长1/3;X线所见:两牙根充完好,无根折,根尖无病变,牙槽骨未见骨折线,叩"-".     

口腔正畸牵引联合多学科综合治疗后牙残根的临床研究

目的观察和评价口腔正畸牵引联合多学科综合治疗后牙残根的临床效果。方法选择2016年1月至2018年12月首都医科大学附属北京友谊医院收治的牙残根患者10例进行前瞻性研究,龋坏或牙折断面不超过龈下4mm。经过牙周洁治和根管治疗后进行正畸牵引,直至残根断面位置达到冠修复牙本质肩领要求。牙周手术修整冠向增生的牙龈及牙槽骨。桩冠修复。通过临床检查评价正畸牵引效果和桩冠修复效果。结果 10例患者后牙残根正畸牵引效果良好,平均牵出的距离为3. 46 mm。其中8例出现了不同程度的牙周组织冠向迁移,通过牙周手术修整了龈缘的位置和形态,牙周手术后2个月进行桩冠修复。冠根比为1. 2～2. 2,具有较好的稳定性和美观性。修复体完成后6个月复查,6例评价良好,4例较好,整体治疗有效率为100%。结论正畸牵引联合多学科综合治疗是保留残根的一种有效方法,修复效果良好。正畸、牙体、牙周、修复等多学科的密切协作和配合是临床治疗成功的保障。     

四种复合树脂嵌体修复牙体缺损边缘微渗漏深度对比

目的对比四种复合树脂嵌体修复牙体缺损边缘微渗漏深度。方法将新拔除的40颗上颌前磨牙按国际嵌体标准制备Ⅱ类洞,应用复合树脂Z350、P60、Ceramage、Solitaire 2制作嵌体各10颗,行Single Bond 2和Rely X ARC粘接,冷热循环500次后品红染色,金刚砂片平行牙体长轴将修复体纵向剖开2次,并在体式显微镜下测量染料渗入轴壁及龈壁的深度。结果四种树脂嵌体材料轴壁与龈壁均出现微渗漏,但不同材料的轴壁与龈壁比较差异未见统计学意义(P0.05);同材料轴壁与龈壁的微渗漏比较差异有统计学意义(P0.05)。结论 Ceramage聚合瓷嵌体是临床上制作树脂嵌体较理想的材料。     

金属烤瓷冠颈缘伸展不当的影响

通常认为,烤瓷冠颈缘位置应平齐龈缘,唇颊侧伸入龈沟不超过龈沟中份,或〈1 mm .目前,大多数专业口腔医师都能按照上述原则进行牙体制备,但在戴牙时对制作方面的缺陷观察、调改普遍重视不够,甚至因为粘接时的疏忽而改变颈缘位置,从而影响临床修复效果.     

口腔修复中牙龈电切术的护理配合

在固定修复中需要良好的牙龈形态与清晰的预备体。龈缘是形成美观、边缘密合修复体的重要条件,以往修复科医师碰到需要牙龈修整的患者,需转牙周科或外科治疗。现代科技具备了ＰｅｒＦｅｃｔＴＭＴＣＳ组织修形系统（俗称电刀）,是利用高频电场产生的热效应能,对牙龈组...     

Intraoral versus Extraoral Measurement of the Height of the Interproximal Contact Area in Maxillary Anterior Teeth

Objectives

This study aimed to clinically quantify the apicoincisal height of the upper interproximal areas directly in patients'' mouths compared to measurements on stone models.

Subjects and Methods

One hundred and fifty participants (75 females and 75 males, age range 20–45 years) were recruited for this study. A digital caliper was used to measure the anterior maxillary interproximal contact areas directly in patients'' mouths and on stone models. The digital caliper accuracy was up to 0.01. The Statistical Package for Social Sciences software (SPSS, version 19.0, Chicago, Ill., USA) was used for statistical analysis. Statistical significance was based on probability values <0.05.

Results

The intraoral measurement of proximal contacts as well as the measurement on stone models showed that the dimensions of interproximal contacts on both sides of each tooth were significantly different (p < 0.001) and that the dimension of the mesial contact point was larger than that of the distal contact point of each tooth. The largest contact point was the one between the central incisors (direct intraoral measurement = 2.9–6.49 mm; model measurement = 3.31–6.91 mm). On the other hand, the contact point between the canine and first premolar was the smallest on both sides of the arch (0.63–2.52 mm intraorally, 0.98–2.88 mm on models). The intraoral measurement of contact points was more accurate than model measurements, and the differences were statistically significant (p < 0.001).

Conclusions

The clinical evaluation of contact point dimensions using a digital caliper was more precise than measuring contact points on stone models; hence, it is a viable, quick and adequate method to be used routinely.Key Words: Contact point, Interproximal contact, Anterior teeth, Dental esthetics     

金属嵌体与复合树脂直接充填治疗垂直型食物嵌塞的疗效比较

目的比较金属嵌体和复合树脂直接充填修复治疗垂直型食物嵌塞的临床疗效。方法选择68例患者垂直型食物嵌塞病例78颗牙随机分组,分别应用金属嵌体和复合树脂直接充填进行治疗,1年随访,对患牙邻接关系,牙龈健康状况及边缘密合度进行比较。结果两组病例在边缘密合度及牙龈健康方面差异无统计学意义（P〉0.05）,而在邻接关系恢复方面,差异有高度统计学意义（P〈0.01）。结论金属嵌体修复在治疗垂直型食物嵌塞时较复合树脂直接充填效果好。     

The impact of arm position on the measurement of orthostatic blood pressure

Blood pressure is a standard vital sign in patients evaluated in an Emergency Department. The American Heart Association has recommended a preferred position of the arm and cuff when measuring blood pressure. There is no formal recommendation for arm position when measuring orthostatic blood pressure. The objective of this study was to assess the impact of different arm positions on the measurement of postural changes in blood pressure. This was a prospective, unblinded, convenience study involving Emergency Department patients with complaints unrelated to cardiovascular instability. Repeated blood pressure measurements were obtained using an automatic non-invasive device with each subject in a supine and standing position and with the arm parallel and perpendicular to the torso. Orthostatic hypotension was defined as a difference of ≥ 20 mm Hg systolic or ≥ 10 mm Hg diastolic when subtracting standing from supine measurements. There were four comparisons made: group W, arm perpendicular supine and standing; group X, arm parallel supine and standing; group Y, arm parallel supine and perpendicular standing; and group Z, arm perpendicular supine and parallel standing. There were 100 patients enrolled, 55 men, mean age 44 years. Four blood pressure measurements were obtained on each patient. The percentage of patients meeting orthostatic hypotension criteria in each group was: W systolic 6% (95% CI 1%, 11%), diastolic 4% (95% CI 0%, 8%), X systolic 8% (95% CI 3%, 13%), diastolic 9% (95% CI 3%, 13%), Y systolic 19% (95% CI 11%, 27%), diastolic 30% (95% CI 21%, 39%), Z systolic 2% (95% CI 0%, 5%), diastolic 2% (95% CI 0%, 5%). Comparison of Group Y vs. X, Z, and W was statistically significant (p < 0.0001). Arm position has a significant impact on determination of postural changes in blood pressure. The combination of the arm parallel when supine and perpendicular when standing may significantly overestimate the orthostatic change. Arm position should be held constant in supine and standing positions when assessing for orthostatic change in blood pressure.     

个体化乳腺癌放射治疗体位固定技术改进方法研究

目的探索个体化乳腺癌放疗体位固定技术的改进方法。方法乳腺癌患者40例,A组(20例)采用乳腺托架固定,B组(20例)采用真空袋、直肠癌体架和热塑体膜联合固定法固定。利用EPID拍摄患者治疗前位置验证片,比较两组摆位误差。结果 B组摆位误差明显优于A组,患者左右(X)、上下(Y)、前后(Z)方向和旋转(R)误差分别为,A组:X(2.90±1.77)mm、Y(3.85±1.98)mm、Z(3.25±1.94)mm,R(1.67±1.27)°;B组:X(1.80±0.70)mm、Y(2.30±1.17)mm、Z(1.75±1.02)mm,R(0.55±0.42)°。两组各项指标差异均有统计学意义(P<0.05)。X、Y、Z三方向摆位误差>5 mm的比例分别为A组15.0%、35%、25%,B组为0、5%、0。B组PTV外放边界由A组的7.04 mm、9.09 mm、7.86 mm缩小至4.09 mm、5.42 mm和4.21 mm。结论新方法整体摆位准确性明显提高,特别是摆位误差≥5 mm的发生率显著下降,PTV的外放边界进一步缩小,减少肺和心脏等正常组织照射体积。     

血流感染患者中性粒细胞参数Neut-X和Neut-Y的临床研究

目的探讨中性粒细胞参数Neut-X和Neut-Y对血流感染诊断的临床意义。方法回顾性分析106例血流感染患者和51例健康对照组资料,比较白细胞、中性粒细胞百分比、Neut-X、Neut-Y和降钙素原的结果。结果血流感染组中性粒细胞参数Neut-X、Neut-Y(1 393.5±33.4、416.2±30.0)均显著高于血培阴性组(1 371.9±32.7、391.7±23.7)和健康对照组(1 347.2±26.2、371.9±21.5),差异有统计学意义(P0.05)。Neut-X、Neut-Y与降钙素原均具有较好的相关性。革兰阴性菌组的Neut-X、Neut-Y高于革兰阳性菌组。结论血流感染患者Neut-X和Neut-Y参数升高,可作为血流感染诊断辅助指标。     

The accuracy of estimating proximal tibial translation during natural cadence walking: bone vs. skin mounted targets

OBJECTIVE: To assess the efficacy of estimating proximal tibial translation using video-based motion capture and an array of surface-mounted targets ideal for tracking motion of the tibia. DESIGN: Superficial and bone-anchored tracking targets were used to create two independent sets of data locating the proximal tibia in a global coordinate system. BACKGROUND: Knowledge of the effect that soft tissue movement has on estimates of proximal tibial translation has not been reported to date. This basic information is necessary to establish construct validity for any study proposing to document tibial translation using standard video-based motion capture methods. METHODS: A six camera motion capture system was used to collect surface-mounted and bone-anchored data for seven healthy adult subjects walking at a self-selected speed. The subjects walked along the positive Y-axis of the global reference system, with the positive Z-axis oriented vertically. RESULTS: Average peak differences in the location of the proximal tibia calculated from the bone and surface-mounted targets were 7.1, 3.7 and 2.1 mm along the X, Y and Z axes of the global coordinate system respectively. Individual subject peak differences were as large as 14.1, 11.8 and 8.3 mm along the X, Y and Z axes. CONCLUSIONS: Estimates of tibial translation with a measurement resolution better than 3 mm are not likely using standard motion capture methods and tracking targets attached superficially to the lower leg. RELEVANCE: The results of this study clearly depict the considerable effect that soft tissue motion of the lower leg has on estimates of proximal tibial translation. Without consideration for the difficulties in measuring femoral, or patellar motion, we believe it is not feasible to routinely obtain sufficiently accurate estimates of detailed knee joint translations using superficial tracking target attachment methods.     

产前超声检测胎儿咽喉及气管直径

目的探讨不同孕周胎儿咽、喉及气管直径的正常参考值范围。方法对401例孕16～36周正常单胎胎儿进行产前超声检查,在清晰显示胎儿咽、喉及气管的基础上测量其直径。结果401例正常单胎胎儿,超声测量胎儿咽直径241例,喉直径314例,气管直径329例。胎儿咽直径从16周时的（2．90±0．40）mm增加至36周时的（9．30±0．42）mm;喉直径从16周时的（3．70±0．32）mm增加至36周时的（11．10±0．87）mm;气管直径从16周时的（1．20±0．10）mm增加至36周时的（3．80±0．31）mm。胎儿咽、喉及气管的直径（Y）与孕周（X）呈显著线性关系,均可拟合直线方程,其回归方程与相关系数分别为Y=-0．76147＋0．27727X,r=0．99039,P〈0．0001（咽）;Y=-0．95126＋0．33805X,r=0．99228,P〈0．0001（喉）;Y=-0．47030＋0．11662X,r=0．99167,P〈0．0001（气管）。结论不同孕周胎儿咽、喉及气管直径正常参考值范围的建立将为产前判断胎儿呼吸道发育不良及相关异常提供有价值的参考。     

后牙种植冠桥修复后邻接触丧失的研究进展

后牙种植冠桥与天然邻牙之间的邻接触丧失是种植义齿修复后最常见的并发症之一。天然邻牙可发生近中漂移,而种植体无此生理学现象被认为是种植义齿邻接触丧失的主要原因。此外,对颌牙类型、上下颌骨骨密度差异、缺牙修复时间、游离端修复、邻牙骨支持水平等因素均参与引起种植义齿邻接触丧失,而后者可直接造成食物嵌塞、邻牙龋坏、牙周炎种植体周围炎等不良后果。本文从种植义齿修复后邻接触丧失的发生率、种植牙的生物学特性、参与邻接触丧失的因素、邻接触丧失的不良后果及其解决方案等5个方面,对后牙种植冠桥修复后邻接触丧失进行综述。      

正畸治疗及戴固定保持器对牙龈健康的影响

目的 评估口腔正畸治疗及戴固定保持器与牙龈健康的关联性.方法 本研究回顾性调查62例受试者,其中34例接受过正畸治疗.测量全部受试者牙龈健康相关参数,包括牙菌斑指数、牙龈退缩、探诊深度和探诊出血,分析各参数与正畸治疗的相关性.结果 与未正畸人群比较,正畸人群的唇侧牙龈退缩更明显[（0.13±0.27）mm vs（0.05±0.16）mm,P=0.03）];在正畸人群中,与未戴保持器的牙弓比较,戴保持器的牙弓发生舌侧牙龈退缩者更明显[（0.09±0.18）mm vs（0.01±0.08）mm,P=0.005）],菌斑指数、探诊出血亦显示相同的差异.正畸人群中,舌面牙菌斑与舌/腭侧牙龈退缩之间有正相关性（r=0.34,P=0.015）.结论 正畸治疗及治疗后戴固定保持器与牙龈退缩、菌斑滞留及探诊出血有关联性,口腔自我护理的重点应放在祛除菌斑上.     

上肢自体动静脉内瘘术前动静脉内径与术后吻合口血流量的超声评价及意义

【目的】探讨上肢自体动静脉内瘘（AVF）术前血管超声测量指标（X）与术后吻合口血流量（Y）的相关性,以指导造瘘术式的选择。【方法】对109例拟行上肢自体AVF的尿毒症患者采用四种AVF术式,在术前行双上肢血管超声检查,测量拟造瘘动脉内径（X1）、静脉内径（X2）;待吻合口成熟后,检测其Y,应用多元线性相关分析探讨X1及X2与Y的相关性。【结果】上肢自体AVF的四种不同术式与吻合口血流量（Y）无明显直线关系（P〉0．05）。拟造瘘血管的X1、X2与造瘘成熟后吻合口Y有直线关系（P值均〈0．05）;以拟造瘘的X1、X2建立模型,复相关系数（R）为0．883,决定系数（R^2）为0．780。根据该模型建立的多元线性回归方程为：Y=-599．062＋168．368X1＋173．263X2,其中X1、X2的标准偏回归系数分别为0．529和0．389,故拟造瘘血管的X1对吻合口Y的作用大于X2【结论】AVF术前对拟造瘘血管超声评估,可在一定程度上指导上肢自体AVF术式的选择。术前测量拟造瘘动、静脉内径值与成熟后吻合口血流量有直线关系。