Im 32 years old, dont drink, smoke, or take medication.  No family
history of any kind of medical condition -- a very uneventful family
medical history.

Last year my teeth were fine.  I could floss as recommended and
everything felt fine however, perhaps the past 7 months my teeth appear
to be getting thinner in width (not depth).  I can actually see tiny
gaps between some of my teeth (in particular the front) which never
were there before.  I can strain water through those gaps significantly
easier than before.  Interestingly this all happened a few months after
i went to the dentist last year.  The front teeth the dentist worked on
have the gaps (he used the white fillings for those areas).

Oddly, when i floss i can actually feel a subtle ridge near the tip of
the tooth just before the floss exits from between the teeth.  I
believe all my teeth have this strange ridge.

My diet hasnt been the best, basically a computer programmer's diet
(chips, coke, and whatever else i can find) but i always floss/brush.
Brushing can be for 10 mins or so and Im careful to not brush against
the gums.

I have an identical twin brother and he isnt experiencing the same
teeth problems at all.  His diet and habits are identical to mine.

Please provide me with your guess as to what is happening with my
teeth.  I'm planning on visitng a dentist in the coming week but still
wanted ANY kind of possiblities this could be.  I want to reasearch on
some good leads before walking in to the dentist.

Thanks for any tips.