This is from the LLLI Professional Liaison Program Newsletter-Volume I,
Number 2:

Clampdown Bite Reflex
Several sources have reported a possible connection between tonic bite, or
clampdown reflex, and the mother's diet.  No studies have been done, but
there are anecdotal cases where the mothers usually had a family history of
allergies and/or birth was difficult, there was usually some separation of
mother and baby and sometimes bottles had been given.  Most of the mothers
did not like milk, but drank it during pregnancy.  Their babies tended to
clamp down with latch-on and improved when dairy products were ommited from
the mother's diet.

Just a thought.

Diane Karnbach, LLLL