数字式曲面体层片评价牙周炎患者下颌骨骨密度

背景：很多研究表明,牙周炎患者不仅有局部骨丢失,系统性骨丢失会加重牙槽骨丢失。下颌骨骨密度、骨质疏松症和牙周炎之间可能存在着一定的联系,但是也有一些研究表明它们之间没有相关性。 目的：通过数字式曲面体层片对牙周炎患者下颌骨骨密度的改变进行评价,分析牙周炎患者牙槽骨丢失和全身骨丢失的相关性。 设计、时间及地点：病例-对照观察,于2005-12/2007-05在南京大学口腔医学院完成。 对象：60名牙周炎患者和60名正常对照者。 方法：摄取数字式曲面体层片,并采取标准化措施用于保证不同个体的一致性。应用计算机软件测量下颌骨牙槽骨指标和皮质骨指标,分析牙槽骨指标和下颌骨下缘皮质骨指标的相关性。 主要观察指标：牙槽骨指标包括牙槽骨骨密度、骨高度;下颌皮质骨指标包括下颌骨下缘皮质骨厚度、曲面体层指数。 结果：两组的牙槽骨骨密度、牙槽骨骨高度及下颌骨下缘皮质骨厚度差异均具有显著性意义(P < 0.05),两组的曲面体层指数差异无显著性意义(P > 0.05)。下颌骨下缘皮质骨厚度与牙槽骨骨密度、牙槽骨骨高度具有显著相关性(P < 0.05)。 结论：与正常对照相比,牙周炎患者的牙槽骨丢失明显,同时其下颌骨下缘皮质骨吸收变薄,牙槽骨丢失和系统性骨丢失之间具有一定的相关性。     

双维控制牙槽骨牵ava张器的研制及动物实验研究

背景：牵张成骨增高牙槽嵴在基础研究及临床已有很多成功报道，双维控制垂直牙槽骨牵张器可有效防止单向直线牵张器行牙槽骨牵张发生轴向移位。 目的：研制双维控制的牙槽骨牵张器，并通过动物实验观察其成骨效应。 方法：选择杂种犬4只，拔除一侧下颌前磨牙形成萎缩牙槽骨模型。1个月后行骨切开放置双维牵张器，7 d后垂直牵张 (1 mm/d，共5 d)。完成垂直牵张后，利用双维牵张器颊向控制功能将移动骨块颊向牵出(大约2.4 mm)，固定2个月后行大体观察及组织学检查。 结果与结论：4只犬中2只黏膜伤口愈合良好，2只黏膜出现裂开，行二次缝合后愈合，牵张器固位良好，未出现松动、脱落。牵张骨块向垂直向及颊向的位移量满足实验目的要求，牙槽骨垂直向高度平均增加(5.0±0.2) mm，颊向宽度平均增加(2.4±0.3) mm。大体观察及组织学检查均证实牵张成骨的骨块新骨形成良好。说明双维控制垂直牙槽骨牵张器能较好的控制移动骨块垂直或颊向的移动方向，并且新骨形成良好。     

利用图像存储传输系统数据库构建下颈椎椎弓根模型及其临床意义

背景：下颈椎椎弓根钉内固定技术具有良好的生物力学强度、三维稳定性和植骨融合率。然而,由于下颈椎解剖结构复杂且个体差异性大,常导致螺钉置入困难,复位风险高。 目的：利用图像存储传输系统结合64排CT片及X射线片于内固定前精确测量下颈椎后方解剖学结构,指导下颈椎内固定过程中椎弓根置钉。 方法：51例下颈椎疾患病例利用图像存储传输系统测量定位法行颈椎椎弓根内固定。同时对比同期开展治疗的两种不同方案的颈椎内固定患者：解剖置钉法26例,管道疏通法17例。以Andrew椎弓根螺钉CT位置分级标准评价3组患者的置钉准确率。 结果与结论：图像存储传输系统测量定位组置钉准确率显著高于其他两组(P < 0.05),图像存储传输系统测量定位组病例均未发现脊髓、椎动脉、神经等组织损伤。提示应用图像存储传输系统结合64排CT及X射线片内固定前测量,能够指导内固定过程中安全置入颈椎椎弓根螺钉,置钉效果明显强于传统的解剖置钉法及管道疏通法。     

参照数字X射线片测量数据行髓室钻孔的可行性

背景：临床上治疗牙髓炎的方法，都是以牺牲牙髓活力为代价且要破坏大量牙体组织，导致牙体容易折裂。但有研究表明牙髓组织具有较强的自我防御能力和自身修复潜能，因此，符合生物学观点的方法是保存活髓。 目的：探讨参照数字X射线片测量数据行髓室钻孔的可行性。 方法：从VixWin PRO图像处理系统调取牙髓室图像清晰曲面断层片60张，进行髓室高度和宽度的测量。髓室高度为前牙及双尖牙髓室顶到髓室两侧牙槽脊顶连线中点的直线距离，或磨牙髓室顶中点到髓室底中点的直线距离；髓室宽度为平行于牙槽脊顶从牙颈部髓室近中内侧壁到远中内侧壁的直线距离。用软件自带的电子尺测量曲面断层片上牙髓室的高度、宽度，计算平均值；观察牙髓室能否容纳两支直径0.55 mm的小儿头皮静脉输液针。 结果与结论：前牙及双尖牙髓室最小平均宽度为0.80 mm，高度为3.43 mm；磨牙髓室最小平均宽度2.35 mm，高度1.80mm。提示牙髓室能容纳两支5.5号小儿头皮静脉输液针，可以在牙髓室钻两个引流孔。     

个体优化经椎弓根置钉复位内固定治疗胸腰椎骨折

背景：在日臻成熟的椎弓根螺钉应用技术中,仅满足于将螺钉置入椎弓根中是不够的,而是应根据骨折复位固定要求寻求最佳置钉通道。 目的：验证经椎弓根内固定个体化治疗胸腰椎骨折的有效性和安全性。 方法：对50例胸腰椎骨折患者内固定前X射线片和CT片进行个体化矢状面及水平面椎弓根螺钉置入角、椎弓根横径、间距、钉道深度、椎体前后高、脊柱后凸角及椎管前后径测量,确定胸腰段椎弓根钉道个体优化置钉和复位的安全范围。术中结合解剖定位标志,C臂X射线机监控置钉并复位骨折椎体,确定复位结果。 结果与结论：置钉位置良好,角度及深度适中,内固定后骨折椎体复位高度、后凸角及椎管面积改善(P < 0.01)。经2~26个月随访,骨折均愈合。提示在胸腰段椎弓根钉道个体化影像测量安全范围内,优化置入椎弓根钉和复位是保证置钉内固定安全和椎体骨折复位合理而有效的方法。     

多层螺旋CT三维重建技术在辅助微螺钉种植支抗植入中的选择应用

背景：提高正畸支抗系统微螺钉种植体稳定性的关键在于种植前对局部骨质、骨量进行精确评估，但常规二维影像学检查，如根尖片、曲面断层摄影片、侧位头影测量片等均存在不同程度的局限性。 目的：分析总结多层螺旋CT多种图像重建技术在辅助微螺钉种植支抗植入中的不同特点及优势，以便精确指导微螺钉的种植，提高其稳定性。 方法：种植前以多层螺旋CT对猪颅骨进行定位扫描及多种图像重建，通过多种图像联合应用初步观测种植区骨质骨量及解剖情况，然后利用计算机在影像上精确设计三维种植角度，根据影像信息制作隧道式手术模板指导种植32枚微螺钉支抗，种植后多层螺旋CT再次扫描重建，将种植前后多层螺旋CT设计及测量角度与术后解剖组织块实物测量角度作对比分析。 结果与结论：32枚微螺钉种植情况满意，无伤及邻近牙根及周围重要组织结构的情况。种植前设计与种植后多层螺旋CT测量角度比较，以及种植后多层螺旋CT测量与实物测量角度比较，在轴位面及侧断面上其差异均无显著性意义(P > 0.05)，且一致性极好。说明多层螺旋CT能够提供精确而丰富的影像信息，恰当选择合理应用能充分实现微螺钉种植影像学检查目的，从而为提高种植的成功率提供可靠保障。     

2型糖尿病伴牙周病大鼠牙槽骨中转化生长因子β1 mRNA的表达*

背景：研究表明糖尿病可以增加牙周病的发病风险,糖尿病可以引起骨代谢的紊乱并导致骨质疏松症,但其具体机制尚未阐明。 目的：通过对大鼠牙槽骨转化生长因子β1 mRNA表达及根尖区骨密度变化的测定,探究2型糖尿病促进牙周病变的机制。 方法：采用高糖高脂饮食喂养、小剂量链脲佐菌素、一次性腹腔注射及正畸结扎丝结扎的方法建立2型糖尿病伴牙周病SD大鼠模型。应用RT-PCR技术检测实验大鼠牙槽骨中转化生长因子β1 mRNA表达,并对大鼠牙槽骨进行骨密度测量及病理切片光镜观察。 结果与结论：与正常对照组、2型糖尿病组、牙周病组比较,2型糖尿病伴牙周病组大鼠牙槽骨中转化生长因子β1 mRNA表达最高,骨密度值最低(P < 0.01)。2型糖尿病伴牙周病组大鼠牙槽骨有骨质疏松倾向。结果提示2型糖尿病可能通过转化生长因子β1的过表达来促进牙槽骨骨质疏松,进而说明2型糖尿病可能通过转化生长因子β1的过表达来促进牙周病变。 关键词：糖尿病;牙周病;牙槽骨;转化生长因子β1;骨密度     

低强度脉冲超声波对Beagle犬Ⅱ度根分叉病变的辅助效应***◆

背景：低强度脉冲超声波主要用于促进骨折愈合及提高新生骨组织密度,尚未见其对Ⅱ度根分叉病变组织学修复效应的报道。 目的：观察低强度脉冲超声波对Ⅱ度根分叉病变的组织学修复效应。 方法：5只Beagle犬各取2颗下颌第4前磨牙颊侧作为实验区,建立Ⅱ度根分叉病变模型,分别分为超声组和对照组并在颊侧缺损龈方根面制备切迹作为参照点,高糖饲养8周。超声组行根面平整术,术后1周行低强度脉冲超声波(90 mW/cm2,1.5 MHz,200 μs,1 kHz)处理20 min/d,对照组行根面平整术和假处理。6周后取实验区域组织制备脱钙切片,苏木精-伊红染色、Masson染色行根分叉区域组织测量分析。 结果与结论：超声组根分叉区新生牙槽骨沿根面生长,根分叉区可见牙龈上皮;对照组根分叉区以结缔组织生长为主,可见大量牙龈上皮和少量新生骨组织。超声组新生牙槽骨胶原呈“红-蓝”相间,以红染为主;对照组呈现蓝染,即超声组的新生牙槽骨胶原较对照组成熟。超声组牙槽骨、牙骨质、牙周膜新生量均大于对照组(P < 0.05)。提示90 mW/cm2低强度脉冲超声波可促进根分叉病变新生牙槽骨胶原成熟和改建。     

DSA图像测量技术在介入神经放射学中的应用

目的探讨DSA图像测量技术在介入神经放射学中的应用价值。方法对我院介入中心1035例患者在进行介入神经放射学检查及治疗过程中应用DSA图像测量技术对病变及正常血管影像进行测量。结果应用DSA图像测量技术对本组病例中的血管及病变进行测量,应用直径为10mm的正圆形不锈钢球作为参照物,并且尽可能将其放置在与预测量血管或病变同侧同一平面位置接近的部位,其测量数值较少产生误差;应用三维重建系统对旋转DSA三维重建的图像也可进行精确测量。结论DSA图像测量技术对介入神经放射学检查及治疗具有重要的指导意义,对于介入操作医生选择合适的支架、保护过滤伞、弹簧圈及扩张球囊等材料的种类、型号至关重要。     

多层螺旋CT辅助微种植体支抗植入的精确性

植区的骨质骨量做细致精确的评估并制定周密的治疗方案是使用微螺钉作为高效正畸支抗的前提。 目的：比较多层螺旋CT各种重建影像在术前评估种植区骨量的精确性,并探求其影响因素,以辅助提高微种植支抗的稳定性。 方法：采用多层螺旋CT原始轴位像及多种重建影像精确设计种植角度后,在成熟普通猪头颅骨种植32枚纯钛微螺钉,术后分别测量多种影像上的微螺钉角度,并沿微螺钉走向测量局部牙槽突宽度。解剖猪颌骨,测量组织块牙槽突宽度及微螺钉角度。将多层螺旋CT多种影像线段和角度测量值分别与实物测量值进行比较并进行统计学分析。 结果与结论：①多层螺旋CT二维平面及三维立体影像上的角度与线段测量值与实物相比较均一致性较好,但均略小于实测值。②原始轴位图像精确度最高,二维平面影像精确度高于三维立体影像。③角度测量值精确度高于线段。④无论二维平面或三维立体影像,轴位面影像精确度高于侧断面影像。提示多层螺旋CT图像可提供与实物大小基本接近1∶1的精确信息,能够准确指导微种植体支抗手术,以辅助提高其稳定性;原始轴位图像与多层面重建中的侧断面图像在角度及线距测量上临床应用价值最大;MSCT放射线基准面选择影响侧断面放大率。     

A preliminary MRI study of the geometry of brain displacement and level of consciousness with acute intracranial masses

We determined the horizontal and vertical components of brain displacement on coronal MRIs in 10 patients with acute supratentorial masses. The vertical distances from the superior sagittal sinus to the pontomesencephalic junction (PMJ) and from the vertical midline of the brain to the PMJ did not differ from measurements in 30 patients without masses. Horizontal displacement of the 3rd ventricle (mean, 5.2 mm) exceeded vertical displacement of the PMJ (mean, 1.2 mm) in all but 1 patient. Total brain displacement near the incisura increased from 3 mm in awake patients to 6 to 13 mm in stuporous and comatose patients and remained predominantly horizontal. Uncal herniation, seen only in a patient who was imaged a day after the onset of coma, did not appear to be the immediate cause of brainstem compression but was accompanied by prominent lateral distortion above the tentorium. This preliminary study suggests that most patients with acute unilateral masses have upper brainstem distortion due predominantly to horizontal shift at or above the tentorium.     

Additional somatosensory information does not improve cerebellar adaptation during catching.

OBJECTIVE: People with cerebellar damage are impaired in their ability to adapt anticipatory muscle activity during catching. We asked whether prior or on-line information about ball weight and drop height could improve the impaired adaptation of people with cerebellar damage. METHODS: Cerebellar and control subjects caught a series of balls of different weights under two conditions. The first condition provided subjects with information about ball weight prior to the series of trials. The second condition provided subjects with information about ball weight, drop height, and time of ball release during the series of trials. Subjects had to maintain their hand within a vertical spatial 'window' during the catch. We measured 3-dimensional position and electromyography (EMG) from the catching arm. RESULTS: With prior information, controls required a few trials to adapt to a new ball weight. Cerebellar subjects were slow, or unable, to adapt. With on-line information, controls were able to catch the ball within the window immediately, showing that they did not require practice to make this adjustment. Cerebellar subjects remained slow or unable to adapt to the changed ball weight even with on-line information. CONCLUSIONS: These results suggest that other, intact central nervous system structures cannot compensate for the role of the cerebellum in generating and adjusting anticipatory muscle activity across multiple joints.     

Visual spatial integrity in the absence of splenium

Several lines of evidence have confirmed that visual integrity among the two hemifields is severely impaired following transection of posterior part of the corpus callosum (splenium). But the extent of this impairment differs for various visual functions. Here, in a posterior callosectomized patient (MD), interhemispheric visual spatial integrity is investigated in three experiments. In the first experiment, MD was asked to make decision about horizontal alignment of two balls presented simultaneously in one of three conditions: both in right or left hemifield, or each in one hemifield. We have previously shown that she is not able to perform a shape-matching task for stimuli presented to different hemifields. But in this task, MD was able to compare location of the two bilaterally presented stimuli significantly above chance level.Then we investigated whether attentive visual object tracking across vertical meridian of the visual field is possible in the absence of splenium. MD had to attentively track one bouncing ball among three identical balls, while it crossed the vertical midline in half of trials. Her performance in crossed conditions was significantly above chance level, but it was lower than uncrossed conditions. Finally, we investigated the contribution of simple interhemispheric temporal signals in performing the attentive tracking task. Results suggest that the patient was not using such temporal signals. Our results suggest that interhemispheric connections other than splenium can contribute in making an integral visual map across hemifields. Such an integrated map can be used for bilateral visual spatial comparisons and visual spatial attention.     

Motion analysis of throwing Boccia balls in children with cerebral palsy

Boccia is a sport suitable for children with cerebral palsy (CP). Throwing Boccia balls requires upper extremity and torso coordination. This study investigated the differences between children with CP and normally developed children regarding throwing patterns of Boccia balls. Thirteen children with bilateral spastic CP and 20 normally developed children participated in this study. The tests in this study were a pediatric reach test and throwing of Boccia balls. A 3D electromagnetic motion tracking system and a force plate were synchronized to record and analyze biomechanical parameters of throwing Boccia balls. The results of the pediatric reach test for participants with CP were significantly worse than those for normally developed participants. The 2 groups of participants did not significantly differ regarding the distance between a thrown Boccia ball and a target ball (jack). Participants with CP demonstrated significantly longer movement duration, smaller amplitude of elbow movement, greater amplitudes of shoulder abduction and flexion, slower maximal velocity of torso flexion and the linear velocity of moving the wrist joint forward, faster maximal velocity of head flexion, and smaller sway ratio compared with normally developed participants when throwing Boccia balls. Participants with CP seemed to mainly use head and shoulder movements to bring the Boccia balls forward with limited torso movement. Normally developed participants brought the Boccia ball forward with faster torso and greater elbow movement while stabilizing head and shoulder movements. Nevertheless, participants with CP did not demonstrate significantly worse performance in the throwing accuracy of Boccia balls.     

A new ball launching system with controlled flight parameters for catching experiments

Systematic investigations of sensorimotor control of interceptive actions in naturalistic conditions, such as catching or hitting a ball moving in three-dimensional space, requires precise control of the projectile flight parameters and of the associated visual stimuli. Such control is challenging when air drag cannot be neglected because the mapping of launch parameters into flight parameters cannot be computed analytically. We designed, calibrated, and experimentally validated an actuated launching apparatus that can control the average spatial position and flight duration of a ball at a given distance from a fixed launch location. The apparatus was constructed by mounting a ball launching machine with adjustable delivery speed on an actuated structure capable of changing the spatial orientation of the launch axis while projecting balls through a hole in a screen hiding the apparatus. The calibration procedure relied on tracking the balls with a motion capture system and on approximating the mapping of launch parameters into flight parameters by means of polynomials functions. Polynomials were also used to estimate the variability of the flight parameters. The coefficients of these polynomials were obtained using the launch and flight parameters of 660 launches with 65 different initial conditions. The relative accuracy and precision of the apparatus were larger than 98% for flight times and larger than 96% for ball heights at a distance of 6m from the screen. Such novel apparatus, by reliably and automatically controlling desired ball flight characteristics without neglecting air drag, allows for a systematic investigation of naturalistic interceptive tasks.     

A novel high-throughput imaging system for automated analyses of avoidance behavior in zebrafish larvae

Early brain development can be influenced by numerous genetic and environmental factors, with long-lasting effects on brain function and behavior. The identification of these factors is facilitated by recent innovations in high-throughput screening. However, large-scale screening in whole organisms remains challenging, in particular when studying changes in brain function or behavior in vertebrate model systems. In this study, we present a novel imaging system for high-throughput analyses of behavior in zebrafish larvae. The three-camera system can image 12 multiwell plates simultaneously and is unique in its ability to provide local visual stimuli in the wells of a multiwell plate. The acquired images are converted into a series of coordinates, which characterize the location and orientation of the larvae. The developed imaging techniques were tested by measuring avoidance behaviors in seven-day-old zebrafish larvae. The system effectively quantified larval avoidance and revealed an increased edge preference in response to a blue or red ‘bouncing ball’ stimulus. Larvae also avoid a bouncing ball stimulus when it is counter-balanced with a stationary ball, but do not avoid blinking balls counter-balanced with a stationary ball. These results indicate that the seven-day-old larvae respond specifically to movement, rather than color, size, or local changes in light intensity. The imaging system and assays for measuring avoidance behavior may be used to screen for genetic and environmental factors that cause developmental brain disorders and for novel drugs that could prevent or treat these disorders.     

种植体周围骨吸收的时间因素

背景：目前，对种植体周骨吸收速度随时间的变化趋势判断尚缺乏临床实验数据支持。 目的：观察种植体植入后周围牙槽骨吸收的情况，评价时间因素对种植体周围骨吸收的影响。 方法：收集2003/2010接受种植义齿修复治疗病例的所有直接数字化全景片，筛选出其中可供分析的全景片，并将其分为种植后即刻，1，3，6和12个月片，对所有全景片进行测量，比较种植体植入后不同时间种植体周围骨吸收速度的差异性。 结果与结论：种植体植入后1个月和6个月之间，3个月和6个月之间，1个月和12个月之间，3个月和12个月之间的种植体周骨吸收速度的差异有非常显著性意义(P < 0.01)。提示种植体植入后1~3个月内种植体周围骨吸收最显著。