Fig.5 shows the sectioned septum, which makes it easy to insert round osteotomes (inset green portion; Fig.6 R) without slipping either into the mesial or distal socket. 

The red line indicates the bottom of the septum is wider than the rounded top.  Once the tip of the osteotome reaches the bottom of the septum, the next larger osteotome does not slip mesially or distally with ease.

Late Infection

Xin Wei, DDS, PhD, MS 1st edition 03/19/2013, last revision 07/29/2013