|
|
Power chain of 3 is placed between UL 3 and 5 (Fig.7: 4.5 months post bracketing, 16x16 ss wires just placed). The power chain is intentionally twisted in the middle to increase retraction power. The space is 2.5 of teeth.
Xin Wei, DDS, PhD, MS 1st edition 07/29/2015, last revision 07/29/2015