My 6-year-old son had his regular checkup with the pediatric dentist
today.  To my surprise, the dentist told me that his first molars were
hypoplastic and undercalcified.  There is actually a small cavity in
one of them.  He said that the enamel is weak and pitted.  The teeth
have a little brown staining in the crevices, and a few white spots.
When I asked him what caused the problem, he said that the most likely
cause was stress at the end of my pregnancy.  He could not tell me how
likely it is that other permanent teeth have been affected.  My son has
one of his lower front teeth partially in, and it looks all right to
me.  It has come in behind the baby teeth, which don't seem to be
budging.  We have to come back in a month to check on this situation,
and he will have sealants on the molars and a filling for the cavity.

I've been reading everything I can find on the internet about the
enamel problem, but I didn't find much information.  The only unusual
stress during my pregnancy was at 7 months, when my older son had to go
to the emergency room in an ambulance.  My husband, my older son, and I
all have normal teeth.  My younger son has been very healthy.  He did
have jaundice during his first week, but it was never serious enough to
require treatment.  He was exclusively breastfed for the first year,
with very few solid foods (my older son has serious food allergies and
this was a preventive measure), and breastfed for the second year as
well.  He did have a fever for a few days when he was an infant, I
can't remember exactly how old.  He's never had fluoride supplements,
we drink bottled water, and I didn't even use fluoride toothpaste on
him until he was about 5.

I'm wondering whether I should take him to an academic practice.  We go
now to a suburban pediatric dental practice with two dentists.  I'm
worried about the health of these molars, and about whether other
permanent teeth will be affected.  His baby teeth are beautiful, white
and straight.

Any information or advice would be greatly appreciated.