CHEYENNE (AP) - At least 800 children under age 4 needed expensive treatment to repair or remove rotting teeth last year in Wyoming, says Dr. Grant Christensen, staff dentist for the state Department of Health.

"In a state the size of Wyoming, that's a significant problem," Christensen said. "It also translates to considerable expense to the taxpayer and state."

The children suffer, too, often coming to the dentist with mouths full of infected, decaying teeth, he said.

"You see these little children with infected faces and abscessed teeth," he said. "They're sick and they hurt, and it's something that's almost entirely preventable."

The children are suffering from bottle-mouth tooth decay, also called early childhood dental caries. They often are allowed to suck on bottles or sippy cups containing sweet liquids or milk that contain sugars. Over time, their teeth decay due to the prolonged sugary bath.

It's a sight Christensen, a pediatric dentist who works in both Rock Springs and Cheyenne, says he sees at least two or three times a day. Because the decay happens before most children have had their first dental visit, the damage can be extensive by the time they are 3 or 4, he said.

The decay can be so severe and extensive that it requires general anesthesia and some combination of nerve removal, crowns, space maintainer implants or teeth extraction.

In some cases, the infection can be life-threatening.

One 2-year-old treated by Christensen had to have her entire set of primary teeth removed.

She will have to subsist on a liquid or pureed diet until she has enough teeth to chew, and will be completely toothless until age 6, he said.

Christensen said he discovered recently that there were more than 650 children under 4 who were hospitalized under the Medicaid program for extensive dental treatment last year.

From that, he conservatively estimated that another 150 outside the Medicaid system also had such treatments.

Dr. Jay Cole, a dentist who has practiced in Cheyenne since 1999, said the condition also seems prevalent in his practice.

"I see it every day," he said. "A lot of times, it is a surprise, because some are as young as 18 months."

Christensen said parents may delay dental treatment for their children out of their own fears of dental treatment, out of the false belief that primary teeth are not important or because they have trouble finding a dentist who will treat young children.

Parents also may be unaware that they should brush their young children's teeth as soon as the teeth appear, using a soft toothbrush and a small amount of toothpaste, Christensen said.

The American Academy of Pediatrics and the American Academy of Pediatric Dentistry both recommend children see a dentist for the first time by age 1.

Christensen also urged parents to limit the amount of sugar their children consume and to brush their teeth twice a day, particularly well before they go to bed at night. Parents shouldn't put bottles or any other food in bed with their children, he said.