Fig.9: Devon, 7.5 years old, diastema between #8 and 9; permanent lateral incisors are exfoliated; there are not enough spaces for permanent laterals (7,10) to erupt; C, H: deciduous canines.

图九：Devon七岁半，中切牙之间缝隙大（8,9），乳侧切牙已经脱落，但是没有足够间隙让恒侧切牙（7, 10）萌出。C, H：乳尖牙

Early Ortho

Xin Wei, DDS, PhD, MS 1st edition 07/16/2013, last revision 08/25/2013