孩子到了替换牙的时期,乳牙迟迟不掉,医学上称乳牙滞留。这是一种较常见的不正常替换牙现象。从照片可以看出,这个孩子已开始进入替换牙时期。下面的四颗新恒门牙已经换长出来,上面中间的两颗新恒门牙也已长出5～6毫米,但是位置长错了。在两颗新的上门牙前面有两颗迟迟不掉的乳牙牙根在挡道,妨碍并阻挡新恒门牙向里(舌的方向)长,而且有被下面四颗新门牙包住的可能。这种现象医 Children to replace the period of teeth, deciduous teeth can not afford to delay, said medicine retention of deciduous teeth. This is a more common phenomenon of abnormal replacement teeth. As can be seen from the photo, the child has begun to enter the era of replacement teeth. The following four new permanent front incisors have been changed out, the top two new permanent front incisors have also grown 5 to 6 mm, but the location is wrong. In front of two new upper incisors, there are two delayed tooth roots that block the new incisors in the way, obstructing and blocking the new incisors in the direction of the tongue (long tongue), and the possibility of being surrounded by four new front incisors. This phenomenon of medicine