I've never had a patient that had tori removed more than once, but
I've only been in practice for 27 years.  That doesn't mean that
your case is not unique.

If you have a history of clenching, you might want to get that
under control.

Steve

    I'm assuming you have no other abnormal bone growth anywhere else.
So-called exostoses can grow in many areas of the mouth.  There are some
metabolic bone conditions such as Paget's disease of bone that should be
ruled out if this condition isn't restricted to the roof of your mouth
or the inside of your lower jaw.  My guess is that you just have
exuberant torus growth, and to the best of my knowledge the cause is
unknown.  However, I have only seen them removed in circumstances where
they are in the way of dentures.  If you aren't a denture patient I must
assume the tori were so large that they interfered with your speech or
eating, or that the overlying mucosa was often traumatized.  Otherwise
these are seldom messed about with.  Sorry if you're the unusual
case--your oral surgeon should be able to discuss this based on clinical
experience.

Steve

Tori do grow back sometime......But it will not need surgery unless it
got as huge as five years ago. Like the above poster......I practice
for about 10 years have perform more than 20 palatal Tori
removal.....None of my patient need a second surgery, and most of them
only removed their tori for denture.