切牙

Approached the central incisor eruption time is 6-9 years old, 7-11 years of age for the lateral incisor.

上前中切牙萌出的时间是6—9岁，侧切牙为7—11岁。

Objective To study the clinical curative effect of superior central incisor diastema restored with Esthet-X.Methods Restored the teeth by color compare and tooth preparation.Evaluated the degree of patients'satisfaction,teeth shapes and color generally after two years.

目的 研究Esthet-X复合树脂修复上颌中切牙牙间隙的临床效果方法通过比色、牙体预备进行牙体修复，2年后综合评价患牙充填后的形态、色泽及患者的满意度。

The results are as follows:(1) With the imposing of orthopedic force of simulating maxillary protraction on maxilla, in the sagittal direction, the maxillary complex of the SD Rats in experimental group grows more quickly than that in two control groups, and the extent of the maxillary complex increases more evidently. The maxillary complex displays anti-clockwise forward and upward rotation.(2) With the imposing of orthopedic force on maxilla, upper incisors exhibit labial-inclined, labioclination of lower incisors changes insignificantly, and the shape and the dimension of skull are not affected significantly.(3) The expression of TGF-3 , in frontomaxillary sutures and palatomaxillary sutures shows different intensity in different extent of time. But The expression of TGF-{3, in experimental group is more intensive than that in two control groups, and that in operated control group and natural growth group has no significant difference.

结果如下：在模拟上颌前牵引矫形力作用下，(1)生长发育期大鼠上颌复合体在矢状方向生长加快，长度明显增加，并表现出向前向上的逆时针旋转；(2)上切牙唇倾，下切牙的唇倾度没有明显变化，颅脑的形态与大小不受影响；(3)额颌缝和腭颌缝中TGF-β_1的表达，同一时段实验加力组要强于手术对照组与自然生长组，而手术对照组与自然生长组之间无显著性差异。

The results of this study suggest perpendicular location of resistance of six anterior teeth is about 14mm gingivally to incisal edge of central incisor.

本研究认为上颌六个前牙的阻抗中心垂直向上位于中切牙切缘龈方14mm左右。

In Angle's Class II,division 1 patients, the upper incisors labially inclined and closed up the upper lip,the lower lip reduced the covering with the upper incisors' crown.

安氏II类1分类错唇齿关系形态特征表现为：上中切牙明显唇倾并与上唇过度贴合，上唇外翻，下唇对上中切牙覆盖明显减少。

Res ults: The maxillary central incisor was similar to the maxillar y lateral incisor in stress distribution. The highest stresses were observed in the root surface, the liwest in the periodontal ligament, the alveolar bone between them .

结果：上颌中、侧切牙的应力分布基本相同；上颌中、侧切牙及其支持组织的应力分布不均匀，牙根部受应力最大，牙槽骨次之，牙周膜最小。

The results of Pancherz analysis shows that the correction of negative overjet is mainly due to the advancement of maxilla and upper incisors. But the position changes of mandible and lower incisors imply that severe maxillary hypoplasia with high angle and/or mandibular retrusion is contraindicated by the method conducted in this study.

头影测量侧位片Pancherz分析法的分析结果表明，本研究中上颌后缩患者反覆盖的矫治主要由上颌骨、上切牙的前移引起的，但下颌骨和下切牙位置的变化提示适应症的选择应注意避免上颌后缩同时伴有高下颌角和／或下颌后缩的患者。

Cysts form anywhere in the incisive canal located in the palatine bone and behind the alveolar process of the maxillary central incisors, or in the palatal soft tissues that overlies the foramen, called the cyst of the incisive papilla.

无论是在切牙管任何位置的囊肿都位于上颌骨，上颌骨中切牙牙槽突的后方，或者在覆盖于壳顶孔上方的软组织内，这种又被称为龈乳头囊肿

BACKGROUND: Studies demonstrated that incisor continuously growing is due to lack of epithelial root sheath formation. However, researches regarding whether receptor activator of nuclear factor κB ligand and osteoclast has correlation with continue root development is poorly understood.

背景：研究表明小鼠不断生长的切牙是由于切牙仅有颈环而无上皮根鞘的形成，但是破骨细胞分化因子核因子κB受体活化剂配体和破骨细胞与不断生长的牙根发育是否相关，目前研究较少。

Of resorption in vertical and horizontal direction.The purpose of this article is to get the average values and standard deviation of the alveolar ridge heights of the upper and lower central incisors and the first permanent molors in adult with normal occlusion by cep...

测量正常成年人60名的结果提示利用新定的标志和线距对无牙颌原有的上下中切牙和第一磨牙的位置有了确定的方法和数据，进而可测得无牙颌牙槽骨的吸收量，因而扩大了头影测量的临床应用范围。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。