Dear friend
thanks for sharing your concern.
it is nice to know that your
dentist is an experienced doctor.
you have said that root piece has been left unknowingly also a bone piece is left unfortunately.
anyways do not worry, these two things can be well managed by your dentist. the root piece should be removed after locating it and the left over bone has to be filed properly.
otherwise these things could lead to
dry socket. again a painful situation. so get it done as soon as possible.
now coming to your query why your jaw line is swollen? that is because the left over root piece and the exposed bone together has led to infection, more or less similar to dry socket. that is why you have pain and swelling there.
i would suggest visit your dentist and he will take care of this infection. simultaneously start a course of anti biotic and
analgesic too.
but your facial swelling needs immediate attention.
get an OPG done this might help you to see other infected teeth any
fracture of jaw due to trauma or infection (
osteomyelitis), cyst, tumour or any other pathology.
hope this helps.
meanwhile do warm saline rinses
thanks