When the residual root and periapical lesion at the tooth #4 (Fig.1) are removed (Fig.2), it is a natural tendency to make an osteotomy along the long axis of the socket (Fig.3 red line).  Because of slanted sinus floor, the position and trajectory of the osteotomy are most likely to be shifted distally (arrow) as the osteotomy increases in diameter (Fig.4 red) and an implant is being placed (Fig.5 green).

Trajectory     Last     Next    Xin Wei, DDS, PhD, MS 1st edition 07/12/2016, last revision 06/06/2020