Preop oral Amoxicillin seems to be associated with reduction in the buccal and lingual (Fig.3 arrow) fistulae at #30, but there is mesiobuccal swelling (Fig.1 *) with 7 mm pocket (Fig.2).  Osteotomy is initiated in the middle of the septum (S).  In fact, it should have been distal ~ 1 mm because of differential bone thickness.

Osteotomy Depth Control Last Next Xin Wei, DDS, PhD, MS 1st edition 10/17/2017, last revision 09/01/2018