牙长轴

when removing the bicuspid full crown, the direction of wallop must be parallel to the long axis of full crown to the best of its abilities.

拆除双尖牙全冠时，冲击力的方向应该尽量与牙冠长轴平行，大小为24.59±5.98kg较为适合。

objective: to evaluate the clinical application of helical ct for the location or treatment of maxilla embedded tooth in the dental orthopaedics.method: 18 cases with embedded tooth of maxilla were made with clinical examination, dentomaxillary pantomography, submaxilla lateral projection and helical ct.the operation be done for supernumerary tooth,distorted teeth,inverted tooth.three embedded tooth of non-inverted tooth were done by orthopaedics.result: among the 18 embedded tooth ,there were 11 palatally and 6 labially presented teeth,1 the 18 patients is mediately with completely inverted supernumerary tooth.all preoperative assessment are one and all in operative or orthopaedics and primary wound healing.

四川大学华西口腔医学院正畸科，四川成都 610041摘要：目的：正畸治疗中对上颌埋伏牙如何定性，定位，并要对此是采取手术拔除［1］或者是正畸治疗进行探讨。方法：对18例（其中1例为2颗多生牙，1颗多生牙已长出，另一颗为完全倒置的多生牙），上颌前部埋伏牙采用临床检查以及拍摄全景片、头侧位片螺旋ct轴位和表面成像等检查［2～4］对埋伏的多生牙、畸形牙和倒置牙共15例采用了相应的手术进路拔除，对形态正常且不倒置的3颗埋伏牙采用了正畸治疗。

Methods Nineteen bone impacted and unerupted teeth in 18 cases selected by orthopantomograph were scanned by 3DX-CT with 1.0 mm slice thickness. Images obtained by 3DX-CT (horizontally, sagittally, coronally) were analyzed after multi-plane reconstruction and 3D reconstruction including the angle of the bone axis impacted and unerupted teeth; maximum radius of the coronal teeth; distances between the tooth and the cortical bone around; distances to the neighboring tooth roots and nerve forum canal; the thickness of the bone tissue, etc.

对经曲面断层片筛选出的18例19枚埋伏牙进行牙科三维CT检查，扫描层厚1.0mm，重建后进行图像三维断面显示（包括水平位，矢状位，冠状位），对牙位图像进行分析及测量（包括埋伏牙牙长轴的角度，牙根弯曲度，牙冠的最大径，与骨皮质的距离，与邻牙根、神经孔／管的距离；骨质的厚度、高度等）。

Upper central incisors moved forward and downward together with maxillary, at the same time they upright in the sagittal plane and tip mesially. 3 The occlusion plane rotated clockwise for about 1.5°. 4 The width increasement effect of RME comes from approximately the equal amounts of skeletal and dental expansion. The mode of dental movement was a combination of body and tipping movements of posterior teeth.

结果：1后牙在宽度方向上为整体移动和倾斜移动相结合的移动方式，但第一磨牙和第一双尖牙稍有差别；牙齿和骨对宽度增加的贡献各占约1/2；2后牙在垂直方向有伸长的趋势；3第一磨牙和第一双尖牙均向前整体移动，轴倾度保持不变；4中切牙整体随上颌骨前部向前向下移动，其牙长轴发生直立，轴倾度增加；5上颌平面发生顺时针旋转。

In pendulum appliance group: the velocity of maxillary first molar distalizing was 0.8mm per month, distal tipping 12.6°,buccal move 0.5mm, horizontal rotation 2.8°; maxillary central incisor move mesially 0.5mm. Conclusion Two methods successfully distalized maxillary molars to appropriate positions.

钟摆矫治器组上颌第一磨牙平均远中移动3.5mm，疗程4.2个月，平均移动速度0.8mm/月；磨牙长轴向远中倾斜角度12.6°；磨牙颊向移位0.5mm；磨牙发生远中舌向水平旋转约2.8°；上颌中切牙切端向远中移动0.5mm。

RESULTS AND CONCLUSION: The course of treatment was 10.4 months, and the velocity of mandibular second molar mesializing was 0.8 mm per month, with 8.5 mm in mesiodistal direction, there was no changes in the vertical direction.

结果与结论：疗程10.4个月，下颌第二磨牙平均移动速度为0.8 mm/月；平均近中移动8.5 mm，垂直向没有变化；磨牙长轴向远中倾斜角度为2.5°，下颌中切牙位置无改变。

Results The accurate position of bone impacted and unerupted teeth in the complex maxilla or mandible anatomy structure were clearly reflected by 3DX-CT scan and 3D reconstruction. Nineteen impacted and unerupted teeth got anticipate effects by formulating different treatments according to 3DX-CT imaging data.

结果 牙科三维CT能清晰显示埋伏牙的形态、大小、位置、长轴角度、与邻牙的结构关系等。19枚埋伏牙依据牙科三维CT扫描提供的影像学信息制定不同的治疗计划，均取得了预期的临床效果。

Therefore, you must release the take the wheel and loosen its teeth in its teeth on the shaft by time cam control rocker, but equipped page machine in its wheel is compact, inconvenient demolition, and pick out the teeth and inspection of pressure on the relative position of the key is to detect many parts of the machinery in a manner worthy, opening the restore time, the earliest possible time to 2300 hours, easily affecting production.

因此必须松开叼纸轮的定位，并且松开叼牙轴上受叼牙时间凸轮控制的摆杆，但由于配页机的叼纸轮安装较紧凑，不方便拆卸，且叼牙与检测压力相对位置是检测多帖关键的机械部位，拆开后，还原时间长，最快也要二三个小时，容易影响生产。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失