A 7 mm implant placed in the middle of the socket may increase the chance to invade the root of #20 (Fig.4 (axial section of CBCT), as compared to that placed more distal (Fig.5).  B: buccal.  A starter or pilot drill is going to be placed immediately distal to the thin septum and 1-2 mm more lingual than buccal with the coronal end of the drill in the middle of the socket.  Insert parallel pins (short and marked) for position and trajectory check.

Thin Septum with Deviated Roots

Xin Wei, DDS, PhD, MS 1st edition 12/04/2016, last revision 12/04/2016