Thanks Catherine for your input. I agree with your point about tongue
retraction, however, I would not classify it as the most common reason for
intraoral hypertonicity. Nor would i say that jaw clenching or chomping is
the most common manifestation of tongue-tie. Rather, the opposite would be
true with tongue-tie and that would be release of seal and too-large jaw
excursions with normal tone.

The mechanism for hypertonic mouth or jaw clench in the presence of "allergy"
is this pathway:

Stress causes the Rreticular Alarm System to signal a flight or fight
reaction of the sympathetic nervous system. This in turn causes the
trigeminal nerve to fire which, as you know, is the nerve that controls the
muscles of mastication, or all the muscles in the  TMJ area. When the
trigeminal nerve fires, it creates a jaw clench which in turn causes the
nerve to fire, and so on and so forth.  The "cure"  is to remove the stressor
that created the fight or flight response to begin with.

Think about any time you may have felt stressed and it resulted in teeth
grinding, jaw clenching, or discomfort in the TMJ. Same mechanism is at work
in "allergy" or colic.

I have seen, (more times than I can count), intraoral hypertonicity disappear
with a well executed elimination diet for the mother. Even if the baby
doesn't have a "true allergy", the symptoms the baby had as a result of the
offending food coming through the mother's milk, removing the offender from
the mother's diet reduces the baby's stress and relaxes the oral
hypertonicity.

I feel yet ANOTHER research study coming on!!!

Anybody else have any insight on this?

Alison