下颌无牙颌牙槽嵴高度及义齿稳固剂与全口义齿固位力关系的研究

本实验研究下颌无牙颌牙槽嵴高度与承托面积的关系、对全口义齿固位力的影响及义齿稳固剂(DA)对固位力的影响。用超硬石膏制作5个不同高度下颌无牙颌模型和1个家兔上腭模型,测量牙槽嵴高度及承托面积,并测定模型使用DA后和家兔上腭使用DA前后的固位力,对所得数据进行分析。牙槽嵴高度与承托面积、牙槽嵴高度与固位力、承托面积与固位力均呈直线回归关系(P<0.01),使用DA后固位力为使用前的2.87倍。下颌无牙颌牙槽嵴高度和承托面积与全口义齿固位力呈正相关,DA的使用可显著提高全口义齿固位力。     

老年患者的可摘义齿修复

目的 了解老年人缺牙及修复情况。方法 依据本院门诊修复科就诊的826例老年人缺牙特点、病因及义齿修复情况。结果 826例老年人中．缺牙者760例．占总数的92%，缺牙病因是龋病和牙周病。曾做义齿修复者393例，占51．72％，其中96例为不良修复体。结论 积极开展老年人口腔卫生保健。根据老年人的口腔特点行义齿修复，以提高义齿的修复水平。     

面部形态与无牙颌牙槽嵴萎缩关系的初步探讨

研究选用正常牙合成年人６０个进行侧位头影测量，并将头影测量值的均数进行了统计学分析，结果表明：上面高、下面高、全面高及下凳七牙区牙槽骨的高度男女比较差异有非常显著性；上颌后牙区牙槽骨的高度及翼上颌裂至上颌前牙区的距离男女比较差异有显著性。据此认为女性短面形多于男性。因此，研究结果支持面部形态对无牙颌牙槽嵴的吸收有一定影响的结论。     

双鸭山地区老年人缺牙及修复情况分析

目的 了解老年人缺牙及修复情况.方法 依据一例一卡制的问诊和口腔检查资料,分析在我就诊的772例老年人缺牙、缺牙病因及义齿修复情况.结果 772例中,缺牙者734例,缺牙率95.1%,主要病因是龋病和牙周病;修复者404例,修复率55.0%,修复体508件,其中不洁修复体64件(12.6%),不良修复体118件(23.2%),不良修复体主要为局部托牙(98件),不良修复的主要原因为义齿设计不当.结论 应积极开展老年人口腔卫生保健和缺牙后修复必要性的宣传,提高义齿修复率,修复体要适应老年人口腔特点,修复后要定期复查,以提高义齿合格率.     

牙槽嵴植骨术后上颌骨生长变化规律及机制的实验研究

研究牙槽嵴植骨术对Wistar大白鼠上颌骨生长发育的影响及机制。选用40只Wistar大白鼠，随机分为4组，分别为空白对照组和第4、6、8周龄手术组。应用定位X线头影测量技术，在术前和术后每隔两周对所有实验动物进行一次上颌骨长、宽、高三个方向生长发育状况的测量和比较。结果表明：（1）4周龄和6周龄手术组，上颌骨长度及前部垂直高度均小于对照组。（2）8周龄手术组，上颌长度与对照组相比无显性差异，但其前部高度发育与对照组相比有显性差异。（3）随手术时间的提前，上颌长度和前部高度的发育障碍更加严重。（4）与正常对照组相比，4周龄、6周龄和8周龄手术组，上颌的宽度发育没有受到影响。结论：牙槽嵴植骨术会严重影响上颌骨长度和高度的发育，鼻中隔前颌韧带系统的破坏使鼻中隔软骨的生物性生长力的刺激不能有效传导至上颌可能是牙槽嵴植骨术后上颌异常生长的主要原因。     

齿槽嵴低平全口义齿修复

齿槽嵴低平全口义齿修复的固位和稳定始终是修复领域需要解决的问题，本文总结了162例下颌齿槽嵴低平患者(其中21例极低平齿槽嵴患者)全口义齿修复的经验和体会，阐述了从取模，颌位关系的转移及校对、人工齿的排列，义齿外形的制作等步骤，所采取的一些有效措施，介绍了具体的操作方法，定期复查修复效果，取得了较好的临床效果。     

部分后牙缺失修复前后下颌牙根尖应力分布的光弹实验研究

目的：探对部分后牙缺必修复前后对下领牙根尖应力分布规律的影响。材料和方法：以环氧树脂制作正常[牙合]及单侧、双侧后牙缺尖的下颌光弹模型，并在翻制好的模型上进行常规活动义齿修复。2．0kg垂直加载后，在光弹仪上对牙根尖及牙槽嵴中相应观测点的主应力大小和方向进行观测。结果：单侧磨牙缺失时，缺牙对侧和缺牙侧余留牙的根尖主应力水平升高、缺牙侧余留牙根尖主应力的远中偏向角度减小，从而使余留牙的负担明显增大；和义齿修复后缺牙对侧牙和缺牙侧余留牙的根尖主应力水平明显回落至正常，但义齿修复区域牙槽嵴所承受的远中颊侧的力明显增大，而且缺牙对侧余留牙的应力水平明显高于义齿修复侧相应的牙槽嵴观测点。当双侧下颌磨牙同时缺失时，余留牙的根尖主应力明显比正常更偏向近中舌侧，而且其上的应力水平电异常增高；活动义齿修复后，余留牙上的应力水平回落至正常水平．义齿修复区的应力水平更低，而且余留牙及义齿修复区的牙槽嵴承力向远中颊侧的分量更大。结论：单侧或双侧磨牙缺失会对下颌牙余留牙根尖主应力的大小及方向造成显著影响，而活动义齿修复后这种影响可以部分消除，但牙槽嵴对咬合力沿下颌骨向后方的传导特征也会随之发生改变。     

羟基磷灰石+骨形成蛋白+纤维蛋白粘合剂复合物增高牙槽嵴的新骨形成反应

目的:观察羟基磷灰石+骨形成蛋白+纤维蛋白粘合剂(HA+BMP+FS)复合物增高牙槽嵴的新骨形成反应。方法:从小牛长骨中提取骨形成蛋白(BMP),首次采用羟基磷灰石(HA)与纤维蛋白粘合剂(FS)以及具有高效骨诱导性的BMP三者复合,形成一种功能互补的新的人工骨材料,用以进行增高犬的无牙颌牙槽嵴,术后3、6、12、24周动物处死取标本作大体、组织学观察、组织学新骨形成量计算、四环素荧光标记显微法、扫描电镜形貌观察、背反射电子图象和X线能谱分析法等检查。结果:发现:(1)实验组术后3周起出现编织骨,6周新骨增加,12~24周有成熟的骨组织相互连结,布满HA微粒间隙。对照组术后3周未见新骨,6周个别HA微粒与基骨接触,12~24周少许新骨长入。(2)新骨组织与HA直接结合,钙磷元素与HA和基骨接近。结论:HA+BMP+FS复合材料可显著地促进HA-基骨界面骨性结合,加快再建牙槽嵴的新骨形成,增加新骨形成量,从形态和功能上大大提高再建牙槽嵴的质量。     

牙槽嵴植骨术后上颌骨生长变化规律及机制的实验研究

研究牙槽嵴植骨术对Wistar大白鼠上颌骨生长发育的影响及机制。选用 40只Wistar大白鼠 ,随机分为 4组 ,分别为空白对照组和第 4、6、8周龄手术组。应用定位X线头影测量技术 ,在术前和术后每隔两周对所有实验动物进行一次上颌骨长、宽、高三个方向生长发育状况的测量和比较。结果表明 :(1) 4周龄和 6周龄手术组 ,上颌骨长度及前部垂直高度均小于对照组。 (2 ) 8周龄手术组 ,上颌长度与对照组相比无显著性差异 ,但其前部高度发育与对照组相比有显著性差异。 (3)随手术时间的提前 ,上颌长度和前部高度的发育障碍更加严重。 (4 )与正常对照组相比 ,4周龄、6周龄和 8周龄手术组 ,上颌的宽度发育没有受到影响。结论 :牙槽嵴植骨术会严重影响上颌骨长度和高度的发育 ,鼻中隔前颌韧带系统的破坏使鼻中隔软骨的生物性生长力的刺激不能有效传导至上颌可能是牙槽嵴植骨术后上颌异常生长的主要原因     

种植修复术前的准备--萎缩性牙槽嵴的重建

20世纪30年代以来,随着口腔医学和生物医学工程的发展和相互渗透而确立的种植义齿修复术,给很多难以常规义齿修复的患者带来了福音.随着研究的不断深入,人们逐渐认识到缺牙区的部位、牙槽嵴的形态、质地等对种植义齿的成功率影响很大.     

Modes of Inheritance of Errors of Refraction

Eighteen families in which both parents had refractions within the range of +4·0 D to −4·0 D and axial lengths seen in emmetropia (22·3-26·0 mm) showed coefficients of correlation of the order 0·5 indicative of polygenic inheritance. Such coefficients were seen for axial length (0·407) and for the cornea (0·487), but not for the lens (which is known to be yoked to the axial length). No such coefficients were seen in 19 families in which one of the parents had axial length outside the emmetropic range (nine families with long axes and 10 with short axes).

The pattern of polygenic inheritance for emmetropia (completely correlated optical components) and errors of refraction up to 4·0 D (inadequately correlated components: correlation ametropia) follows that seen in stature and other measurable characters. In contrast the high refractive errors with their abnormal axial lengths (component ametropia) are—like the extremes in stature—pathological anomalies with monofactorial inheritance.

     

Level of functioning of siblings and parents of probands of varying degrees of retardation

A further analysis of already published data supports the position that retardates of low ability level less frequently have retarded siblings, retarded parents, and parents low in occupational level than do retardates higher in ability level. The analysis supports the position that there are two types of retarded individuals, persons retarded as a result of gene or chromosomal anomalies, brain injury, etc., who more frequently occur in the lower-level retardate group, and persons whose retardation represents polygenic segregation, who more frequently occur in the higher-level group.     

Recovery of responsiveness of cells of lateral geniculate nucleus of rat

1. Recovery of responsiveness of single cells in lateral geniculate nucleus of rat has been determined in both P and I cells. There are three types of recovery curve among P cells; (a) early recovery, (b) early partial recovery followed by depression and then complete recovery, (c) prolonged depression followed by cyclic recovery. Type (c) is by far the commonest recovery curve. In contrast to the spike in a P cell, the synaptic potential recovers to its full amplitude in about 20 msec. All I cells exhibit similar rapid recovery curves after a prolonged depression.2. Conditioning stimuli applied to visual cortex also produce a prolonged depression in most P cells but I cells can be re-excited at short intervals from cortex. Decortication does not prevent the prolonged depression of the multineuronal response produced by optic nerve stimulation.3. A neuronal model is proposed to explain these observations. It is supposed that I cells (interneurones) are innervated by axon collaterals of the P cells (principal cells, projecting to visual cortex) and that the I cells exert an inhibitory influence on the P cells.     

Analysis of two types of dopaminergic responses of neurons of the spinal ganglia of rats

It was established, in experiments on isolated spinal ganglia of adult rats in concluons of intracellular recording, that dopamine (1 M/liter) elicits depolarized responses in 61% of neurons, hyperpolarized in 20% of neurons, and depolarized-hyperpolarized in 19% of neurons. The depolarized responses are associated with the activation of D₁ dopamine receptors, and are governed by the shift of cAMP-dependent cation (sodium) channels to the conducting state. The hyperpolarized responses are triggered by the activation of D₂ dopamine receptors, which by means of HTP-binding protein convert the potassium channels to the conducting state. The change in the polarization of neurons with the action of dopamine influences their electrical excitability variously.Translated from Fiziologicheskii Zhurnal SSSR imeni I. M. Sechenova, Vol. 76, No. 6, pp. 739–745, June, 1990.