I agree with Ruth that it would be useful to have a teat that would be more
similar to a human breast, but the truth is the human breast and nipple has
great variability in terms of size and elasticity, and this, in itself, can
create challenges for the breastfeeding infant.

As I understand it, researchers in Peter Hartmann's lab are calling into
question the notion of milk sinuses.  They seem to think that all the ducts
expand and enlarge during letdown and that the bulb-like structures we've
described to mothers don't exist.  So we are still learning.  I think that
latching to the shaft of the nipple has the effect of pinching off the ducts
rather like crimping a hose or biting a straw.  So getting the stripping
action of the jaws and tongue located on the breast is important whether
there are sinuses or not.

My interest in flanged lips comes from reading the OT and Speech Path. lit
where facial tone issues are much discussed.  If there is weakness at the
lips (or cheek or tongue), a baby will compensate by rolling in the lips and
exerting excess tone.  This lip retraction prevents a smooth seal.  Put your
thumb in your mouth and make a tight seal with your lips and suck.  Lots of
suction.  Now flare one corner of your lips and see what happens when there
is even a small vacuum leak.  The strength of the suck goes way down.  So
the smoothly flanged lips are an issue with seal, which has profound
repercussion for suction.

On the issue of teat length.  Do we really have any published data on the
correct length of a teat?  We know from the dental lit that there is
tremendous anterior to posterior length change in the mouth during the first
4 months because of the rapid growth of the head and the pulling forward of
the receding lower jaw.  I have measured a lot of babies of diff. ages using
my finger and a pen mark and then holding a ruler up to my measure.  I'd say
the average span of a term newborn palate from the palate junction to lip
closure is about 2.7cm.  Peter Hartmann's lab's ultrasound work shows the
nipple coming just short of the palate junction, which would make sense in
terms of where the gag reflex is triggered.  So perhaps a slightly shorter
teat is reasonable in newborns.  Some newborns with poor lip tone can't make
an Avent work because they can't seal around such a large bulb.  But it can
be a good device to help move a baby who can only seal around a small
diameter teat toward being able to open wider and seal tighter around  a
larger one.  Remember, my goal is to move the baby to the breast.  So I want
to go gradually in stages the baby can tolerate.

Finally, I always see the selection of tool use as very individual.  I don't
always use an Avent.  I use the tool that works the best for the baby I have
assessed.  If I have a baby with a hyperactive gag reflex, it would be very
dangerous for me to insist on a longer teat.  I might be very wise to start
with a short one and graduate to increasingly longer ones.  If I have a baby
with a cleft who can't seal off no matter what, I'm going to forget about
the issue of suction as a lost cause and switch to a Haberman that doesn't
depend at all on ability to create suction.  Etc.

My thanks to Ruth for opening up a stimulating discussion.

Barbara Wilson-Clay BSEd, IBCLC
Austin Lactation Associates
http://www.lactnews.com

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