The intruded canine is related to the low placement of the bracket (Fig.2" white line).  The bracket for the extruded central should be placed more incisal (Fig.3" arrow).  The intrusion should be done (Fig.4") before closure of the diastemata, since anchorage may be weakened when the separation between UR1 and 3 increases by using open coil spring.

Before/After Last Next

Xin Wei, DDS, PhD, MS 1st edition 10/20/2019, last revision 10/20/2019