牙骨

In addition, root resorption of deciduous teeth is not continuous, but discontinuous, intermittent stage in the absorption, the absorption of root surface can be deposited new cementum, may also be near the new bone.

另外，乳牙的牙根吸收不是持续不断的，而是间断的，在吸收间歇阶段，被吸收牙根的表面又可以沉积新的牙骨质，附近也可产生新的牙槽骨。

BACKGROUND: Hydroxyapatite has favorable biocompatibility, can protect pulp tissue and promote the formation of osteoid dentin and the concrescence of pulp tissue.

背景：羟基磷灰石具有良好的生物相容性，可保护牙髓组织，促进骨样牙本质的形成和牙髓组织的愈合，但无抗感染能力。

Based on this background, maxillary central incisors was prepared as residual roots model, the materials which has the similar physical properties and capabilities as that of the alveolar bone and periodontal membrane respectively were chosen.

基于上述情况，本实验以人离体上中切牙制备实验模型，以力学性能近似的材料模拟牙槽骨、牙周膜和桩冠修复后的上前牙，制作与上前牙口内受力角度相同的夹具及压力头，形成加载测试系统。

Stress distribution of the natural periodontal membrane, bionic periodontal membrane and the bone interface of the three models are calculated out by SuperSAP93, when the same load exerted to the three models. Results The stress change of the inside and outside surface of the natural periodontal membrane and bionic periodontal membrane is in the same tendency.

应用螺旋CT对上颌中切牙标本进行扫描，分别建立仿生种植牙、天然牙和骨性结合种植体模型，对3个模型施加同样的载荷，应用Super SAP93软件，计算出天然牙周膜和仿生牙周膜以及3种模型骨界面上的应力分布。

The using of cephalogram is limited because of the structure overlapping of the skull, jaw and teeth, for example the overlapping of the right side teeth and the left side make it difficult to distinguish the landmarks of posterior teeth.

颅颌骨牙齿之间影像的重叠使头颅定位x线片的应用受到了限制，比如牙列的重叠使后牙区的标志点难以辨认，所以对牙列的研究要借助牙〓模型。

For the abutment with severe bone lost, pontic width reduction can significantly reduce the stress in PDL of it, and protect the health of remaining periodontium of abutment.

对于基牙牙槽骨高度降低的固定桥，桥体减径可以更加明显地降低基牙牙周膜应力，对桥基牙起到保护作用。

Its mechanism is downward and backward rotation of the mandible, the retrusion of the lower incisors, the protrusion of the upper incisors and the forward growth of maxilla.

FR-Ⅲ是矫治替牙期前牙反的理想方法之一，其机理是下颌骨向下、向后旋转，舌倾下切牙，唇倾上前牙，促进上颌骨向前生长。

In order to observe the capacity of composite artificial bone made from collage/Nano tricalcium phosphate conducting subperiosteal bone formation and investigate the possibility applied in reconstruction of astrophy aveolar ridge, the composite artificial bone was implanted into subperiosteum of the cranial bone in rabbits.

将胶原与纳米磷酸三钙复合制成复合人工骨并植入兔颅骨的骨膜下作为实验组，使用显微镜测微尺测量不同时间点新骨自骨表面长入材料内的高度，并和羟基磷灰石组作对照，观察 Co/N- TCP复合人工骨引导成骨能力，探讨其用于萎缩性牙槽嵴重建的可行性。

Results Normal overbite and overjet were established, the mandibular dentition was distalized and significantly uprighted, a slight proclination was found in the upper anterior teeth, the relative relationship of upper and lower lip get some improvement but few for skelecton.

结果 前牙均建立了正常的覆覆盖关系，下前牙舌侧倾斜、移动及下磨牙远中竖直、移动明显，上前牙轻微前倾，上下唇相对位置获得改善，骨改变不明显。

Drills in the median line with the small crack marks the good median line position, The horizontal osteotomy is then completed with a saw, and removal of midline wedge of bone from a lingual approach.

在中线用小裂钻标记好中线位置，在左右下牙6到6之间截骨，截骨完成后，再于颏部中央截取底边在舌侧的等腰三角形骨块，将颏部骨块内旋，在唇侧表面以微型钛板固定。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。