| 1. | Mandibular central incisor
下颚正中门齿 |
| 2. | Maxillary central incisor
上颚正中门齿 |
| 3. | Keep the toothbrush upright when brushing the inside of the central incisors . brush the part from gums to dental crown with proper strength
刷门牙内侧面的时候，牙刷要直立放置，用适中的力度从牙刷向牙冠。 |
| 4. | The case was a 12 years old girl with an impacted maxillary right canine and a supernumerary tooth located in between two central incisors
本文介绍一位12岁的女孩病例，临床检查发现上颚犬齿阻生以及门齿间一颗多生牙。 |
| 5. | Results : with the loss of the alveolar height , the maximum equivalent stress and the principle stress of the upper central incisor periodontium increased
结果：随着牙槽骨高度的降低，上中切牙牙周膜最大等效应力和主应力逐渐增大。 |
| 6. | Methods : spiral ct ( sct ) scanning technology , digital image transfer and transcription were used to obtain the initial 3 - d data of the upper central incisor
方法：采用螺旋ct扫描、数字影像传输与转录方法，获得中切牙三维形态的原始数据。 |
| 7. | As early as 4 months , the first primary , or baby teeth , to erupt through the gums are the lower central incisors , followed closely by the upper central incisors
最早在4个月的时候，首先萌出的是下颌第一乳切牙，紧接着萌出的是上颌中切牙。 |
| 8. | Permanent teeth begin appearing around age 6 , starting with the first molars and lower central incisors . this process continues until approximately age 21
恒牙萌出于6岁左右，开始于第一恒磨牙以及下颌第一中切牙。这个过程一直持续到将近21岁。 |
