牙

Results Maxillary first and second molars were more mesially inclined in the first group, particularly in the younger subjects (16～25 years). This inclination increased with age.

结果 上颌第三磨牙萌出组与未萌出组相比，上颌第一磨牙和第二磨牙更向近中倾斜，而且随年龄的增加倾斜度也变大。

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。

The position changes of mandibular molars were measured from mesiodistal direction and vertical direction, and the implant anchorage loss was evaluated by maxillary central incisor.

通过测量下颌第二磨牙在近远中方向、垂直向的位置变化，以衡量磨牙的位置改变。并通过下颌中切牙的位置变化，评价支抗强弱。

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。

Both upper and lower dental study models were collected from 30 boys (12 years old) and 30 girls (12 years old) with acceptable normal occlusion to understand the characteristics of the crown size, dental arch width and length such as (1) mesiodistal diameters of crown size from central incisor to first molar,(2) the width and length of dental arch and basal arch and (3) the morphology of dental arch form. After statistical analysis, data were compared with Japanese, Central and South American Indians and North American Caucasians from papers. The results were:(1) There was no statistical difference in teeth size between males and females, except the upper first molar of males was larger than that of females, lower central incisor of males was smaller than that of females.(2) The dimensions of dental arch of males were larger than that of females in general, especially such items as width and length of basal arch.(3) The crown size of Chinese male was in generally smaller than that of four other races, especially the upper canine, lower central incisor and first molar.

为了解住在台湾的中国人其牙齿的大小，齿列弓幅径及形态，为齿科人类学上的特微，以期能对儿童牙科，齿颚矫正科之临床及齿科基础医学能有所贡献，抽取12岁学童男女各30名共60名，可接受为正常咬合之上下颚齿列模型，测量其上下颚(1)左侧正中门牙到第一大臼齿共计12颗恒牙之牙冠近远心径，(2)齿列弓宽径、长径及齿槽基底宽径、长径，(3)齿列弓之形态，以上资料经统计分析作t-test检定，并与诸学者对日本人、北美白人、中美及南美印第安人人种的研究结果作检讨得知；(1)男女性恒牙的近远心径无明显差异，但男性上颚第大臼齿比女性者大，下颚正中门牙比女性者小；(2)男性的齿列弓幅径比女性者为大，尤以齿槽基底宽径及长径最显著；(3)国人男子的牙齿近远心径比其他四人种者为小，特别是国人的上颚犬齿，下颚正中门牙及第一大臼齿最小。

Company main product includes: cutting teeth oblique films, straight teeth Cutting tablets, cutting tablets toothless, Mopan, such as electroplating.

本厂主要产品有：斜牙切割片，直牙切割片，无牙切割片，电镀磨盘等。

Wisdom teeth already the Qu is bad, or dens neurapophysis happen ingluvitis, again the inconvenience carry on the dens body dens neurapophysis treatment

智齿已龋坏，或发生牙髓炎，又不便进行牙体牙髓治疗者

For mid-degree four wreaths plain tooths arriving depth change countenance, fluorine spot tooth etc., for example flush, hair ash, nigrescent time of bleach of four wreaths plain tooths is long, ineffective.

对於中度到深度四环素牙变色、氟斑牙等，比如发红、发灰、发黑的四环素牙漂白时间长，效果不佳。

Key words: molar distalization;classⅡ malocclusion orthodontics;nonextraction

推磨牙向远中；安氏Ⅱ类错牙合；非拔牙矫治

Objective :To investigate the relationship between various occlusal contact and the stress distribution of remaing tooth structure.

目的： 研究不同牙合接触形式对前牙桩冠牙本质应力分布的影响。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。