Because be lengthened as what lack tooth time, bone of chamfer of tooth of the area that be short of a tooth is met gradually atrophic, become low, and speed of much place atrophy is abhorrent still.

• 因为随着缺牙时间的延长，缺牙区牙槽骨会逐渐萎缩，变低，而且多部位萎缩速度还不一致。