磨牙

Objective To investigate the stress intensity and distribution in the dentine of intact endodontically treated mandibular second premolar under three different restorations.

目的采用3种不同的设计方式修复根管治疗后牙冠完整的下颌第二前磨牙，观察其牙本质的应力大小及分布情况。

Methods Animal models were established by ovariectomy and exodontia on left partial Maxillary.

方法通过去除SD大鼠双侧卵巢，拔除单侧上颌磨牙，建立骨质疏松的剩余牙槽骨动物模型，并在此基础上通过免疫组化方法观察、分析切除卵巢及单独和联合运用生长激素、雌激素对去势大鼠剩余牙槽骨内胰岛素样生长因子分布和表达的影响。

Not necessarily, you can give her something like biscuits will do, I always thought that plastic and molar teeth dirty bar, each time the gutta cleaned boiled, and to the baby, she will be tired for a few, and then picked on the throw, and from the moment want to pick up his mouth to send, then I would not let it close up and then the.

不一定，可以给她吃点饼干之类的也行，我总认为牙胶和磨牙棒很脏，每次把牙胶洗干净用水煮了，给孩子，她用不了一会就会厌烦，然后随手就扔了，过一会又想拿起来往嘴里送，后来我就把它收了起来不让再用了。

METHODS: Three-dimensional finite element mandible model was established based on the CT scanning data. The mini-implant was implanted in the region between first mola and second premolar at 30°, 60° and 90° tilted mesiolly, and 30° and 60° tilted occlusally, respectively.

应用颌骨CT扫描图象建立三维有限元模型，在下颌第1磨牙及第2双尖牙间分别以牙合向30°，60°，90°，近中向30°，60°植入种植体，给以水平方向1.96 N 加载。

The static loads were simulated according to the restored and unrestored situation. The stress distribution and stress level of the second molar was recorded.

并在修复前对两个基牙加载，修复后对固定桥进行加载，观察第二磨牙牙槽骨的应力分布变化情况。

Methods:Select 11～18 year old patients with bimaxillary protrusion 20 cases were randomly divided into two groups:TPA group,TPA＋Nance arch group.Two cases are the uprooting of four first premolars,the use of straight wire appliance technology,one step closure extraction gap analysis before and after treatment lateral skull X ray film and dental cast changes in the indicators.

选取11～18 岁双颌前突患者20 例，随机分为：TPA与TPA＋Nance弓两组；两组病例均拔除4个第一前磨牙，使用直丝弓矫治技术，一步法关闭拔牙间隙，分析治疗前后X线头颅侧位片及牙颌模型的各项指标变化。

Methods: 62 cases with anterior deep overbite were treated with a modified appliance which was composed of four parts-the anterior bite plate,the anchorage on the second molars,the rectangular wire with higher elasticity and intermaxilla traction.

该矫治方法由前牙平导板、高弹性方弓丝、第二磨牙设计支抗、后牙颌间垂直牵引等组成。结果：经临床应用2 年，共62 例，效果良好。平均疗程4 个月。

Base on the stress analysis, the model with unit of porcelain to metal at the labiocervical margin is better than the models with porcelain or metal only at labiocervical margin for upper central incisor restoration.

从受力分析的角度而言，金属颈环型设计适应于前磨牙和后牙的修复：瓷颈环型设计适应于前牙修复，而金-瓷混合颈环型设计则适应于任何形式的修复体。

Methods The majority patients were Corrected with edgewise appliance after draw four molars, all sorts of flexure were curved on the appliance, used perpendicular traction for anterior teeth and II, III maxillomandibular traction, fine adjust intercuspal position ,tip and cavity.

多数患者采取拔除4个磨牙之后使用方丝弓矫治器矫治，矫治中在弓丝上弯制各种曲，并使用前牙垂直牵引和颌间Ⅱ类、Ⅲ类牵引，精调牙位及尖窝关系。

Objective:Statistical analysis of mandibular molar mesiodistal crown width and tooth length and development of root.

目的：统计分析下颌第一、第二、第三磨牙牙冠近远中宽度、牙体长度、分根情况以及相关因素。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。