After change in trajectory (Fig.2), Expander 1 (Fig.3: E1, 1/1.6 mm) can be inserted at #14 and 15, while E2 (1.2/2.3 mm) cannot at full length at #14 (as compared to Fig.1), suggesting hard bone.

>200 Units No Expander Last Next

Xin Wei, DDS, PhD, MS 1st edition 07/31/2017, last revision 06/13/2019