?牙位置异常

... Cleanness of teeth in that area make many people die. 那个地区的食物缺乏导致多人死亡。 Anomaly of tooth position 牙位置异常 In truth, both root development and the stimuli that initiate tooth eruption are complex and still little understood. 事实上，牙根的发育以及让牙齿冒出的刺激都很复杂，目前知道得很少。 ...