A 额外牙导致上颌左右中切牙萌出早期出现间隙 B
上下恒切牙萌出早期,可出现前牙反<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12258384_0_1.gif"> C
恒侧切牙初萌时,牙冠向近中倾斜 D
上下颌第一恒磨牙建<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12258384_0_2.gif">初期,为完全远中关系 E
待侧切牙萌出,间隙逐渐消失