anterior teeth residual root前牙残根
teeth root canal牙根管
primary teeth root canal乳牙根管
hypoplasia of teeth root牙根发育不良
teeth root patterning牙根形态发育
posterior teeth root canal后牙根管
teeth root faractures牙根折裂
Why no root teeth away掉了的乳牙为啥没牙根
residual root of teeth牙残根