What are the chances that my bones will drift back to pre operative position?

More commonly it is the
cartilage that has “memory” and is a bigger problem with return to the
undesirable direction. If at 6 months your nose has kept straight, you
can take a breath in the confidence that is not likely to shift any further.

  At 6 months, the bones have healed, and they should not drift.Kenneth Hughes, MDLos Angeles, California

The nasal bones are well set at 6 months after the rhinoplasty. They're usually very well set at 6 weeks after the rhinoplasty procedure and should not drift at all, unless  you get hit in the nose