The apex of LR3 is distal and the root is apparently not longer than that of LR4 (Fig.5).  It appears that extraction of LR3 is more appropriate.  In fact LR3 is longer than the upper premolars

Asymmetric Extraction Last Next

Xin Wei, DDS, PhD, MS 1st edition 02/04/2018, last revision 03/15/2020