Out of the mouths of babes comes … fluorosis?

Pediatric dentist Dr. Gary Cook sees it in his office: the faint, tell-tale white lines on teeth that indicate a child has gotten too much fluoride.

“You see it and wonder where it comes from,” said Cook, who has been in practice since 1981 and sits on the board of the Michigan Academy of Pediatric Dentistry.

You ask, ‘Are they using toothpaste too early? Are they swallowing toothpaste? Or is it another, systemic problem such as chronic ear infection?’ You have to be a detective.”

The American Dental Association says the proper amount of fluoride helps prevent and control tooth decay, and that some exposure to infants’ developing teeth also plays a long-term role in prevention.

But it’s possible to get too much of a good thing.

White streaks on enamel

Fluoride intake above the recommended level for a child’s age creates a risk for enamel fluorosis, a condition that affects the way teeth look. In most cases, fluorosis appears as barely noticeable white lines or streaks on tooth enamel and does not affect the function of the teeth.

“Fluorosis itself is not a disease,” Cook said. “It’s a consequence of overexposure.”

If it’s severe enough, fluorosis can cause mottling, a brown-yellow blotchiness on the teeth. It is not reversible, but there are treatments that can improve appearance, including varnish, microabrasion and veneers.

“You can’t make it go away completely, but you can bring affected teeth in closer balance with unaffected teeth,” he said.

Formula warning

Last year, the ADA recommended babies not be fed infant formula mixed with tap water to minimize the risk of fluorosis.

Cook said he tells parents of patients younger than 1 to buy purified water to mix with infant formula, most of which already contains fluoride.

The recommendations apply only to infants 12 months or younger who need less fluoride than everyone else because of their size.

We’re not talking about toxicity here. To reach a level where fluoride is toxic, a person would have to eat about 12 tubes of toothpaste.

But Cook said fluoride is found in most public water supplies, including Grand Rapids’, and in some juices and mouth rinses, and some vegetables are packed in fluoridated water.

The ADA recommends reducing fluoride intake from infant formula in a variety of ways, including using breast milk, ready-to-feed formula and powdered or liquid concentrate infant formula mixed with water labeled “purified,” “demineralized,” “deionized,” “distilled” or “reverse-osmosis filtered.”

The ADA recommendation came on the heels of a U.S. Food and Drug Administration decision allowing bottlers to claim that fluoridated water may reduce the risk of dental cavities or tooth decay, and the release of the National Research Council Report: “Fluoride in Drinking Water: A Scientific Review of EPA’s Standards.” Both reports can be found on the ADA Web site: ada.org

Cook said fluorosis doesn’t show up until permanent teeth break through the gums, at about 6 years old.

Though he suspects the recommendations aren’t widely known among parents, Dr. Amy DeYoung, a Grand Rapids pediatric dentist in practice for 12 years, said she does hear from those who use purified instead of tap water.

DeYoung, president of the West Michigan District Dental Society, said she doesn’t see a lot of fluorosis in her patients.

And she would recognize it. DeYoung, 40, and her brother, who is a year younger, both have teeth with faint evidence of too much fluoride as children.

“I see (fluorosis) in our generation more,” she said. “I think it’s because we’re more aware that there are limits.”

According to 2002 Centers for Disease Control statistics, more than 60 percent of the U.S. population is served by fluoridated drinking water. As of 2004, the CDC reported that 86 percent of Michigan residents on public water supply systems received fluoridated water.

Grand Rapids is the model for public water supplies across the country. A downtown sculpture recently was dedicated to commemorate the city as the first in the U.S. to have fluoride added to the water supply on Jan. 25, 1945.

Given recent boil-water advisories and E. coli warnings, the “as little tap water as possible” recommendation for infants doesn’t seem to extend beyond fluoride concerns.

Recommendations questioned

Dr. Lisa Hoekstra, a family practice physician at Jupiter Family Medicine in Belmont, said she doesn’t make any recommendations on the issue.

“Actually, there have been some studies done with bottled water that show it is generally no more pure than tap water,” she said.

The fluoride-tap water recommendation for infants isn’t the first of its kind.

In 1997, research suggested young children may be getting more fluoride than they need through baby foods, according to a study published in the Journal of the American Dental Association.

Cook said the reiteration likely is due to increased awareness about sources of fluoride.

DeYoung agreed. “We’re always revising.”

Related Web sites

American Dental Association: ada.org/public/topics/fluoride/infantsformula_faq.asp

ada.org/public/topics/fluoride/facts/fluoridation_facts.pdf

American Academy of Pediatric Dentistry: aapd.org/publications/brochures/floride.asp

aapd.org/publications/brochures/fluorosis.asp