V.B.
Not sure what insurance plan you are under, but have you also considered an FSA? You must have a high deductible plan to have an HSA, but that is not a requirement with an FSA. The down side is that you lose whatever you don't use after the first quarter of the following year. But, if you know approximately what you will spend in out of pocket health care expenses, then you can avoid any losses, and still get a bit of a tax break. I think the limits this year are around $2500.
We use an FSA, and pay for allergy shots, prescriptions, eye care (contacts, glasses and optometrist care), orthodontic care, and whatever other random events. With kids, there always seems to be something. With the orthodontic treatment, we have NO concerns about leaving any funds unspent. :(