THURSDAY, Dec. 18 (HealthDayNews) — The image of a grinning grandma without any teeth is becoming a thing of the past.

A growing number of older Americans still have their teeth, according to new research released Thursday by the U.S. Centers for Disease Control and Prevention (CDC).

The first state-by-state analysis of “tooth retention” found that in 26 states (52 percent), more than half of adults aged 65 and older still had most of their natural teeth. (“Most” meant they had lost not more than five teeth.)

The retention rate continues a decades-long trend toward better mouth care. In the 1950s, more than half of adults aged 65 and older had lost all their teeth. Now only a third have lost all their natural teeth.

“We expect that rates of complete tooth loss will continue to decline substantially as younger persons, who had much lower rates of dental cavities and tooth extraction during their young adult years, age,” says study author Dr. Barbara Gooch, a dental officer with the CDC’s National Center for Chronic Disease Prevention and Health Promotion.

“We’ve seen this growing anecdotally for years,” adds Dr. Matthew Messina, a Cleveland dentist who is consumer advisor to the American Dental Association. “It’s just nice to have hard numbers for what we’ve all known to be true, which is that more people are keeping their teeth for a lifetime.”

But this good news brings with it a continuing oral-hygiene burden: If you have the teeth, you need to keep brushing, flossing, visiting the dentist and drinking fluoridated water even if your knees are creaking. Otherwise, you’re at greater risk for cavities and gum disease.

“It’s very important to have regular use of dental services. And self-care practices, including fluoridated toothpaste, will not eliminate disease but can prevent some components of them,” Gooch says.

The study, which appears in this week’s issue of the CDC’s Morbidity and Mortality Weekly Report, relied on 2002 data from the Behavioral Risk Factor Surveillance System survey, which is conducted by telephone in all 50 states plus the District of Columbia, Guam, Puerto Rico and the U.S. Virgin Islands.

Different states had widely divergent rates of tooth retention. In Kentucky, for instance, 42.3 percent of older adults had lost all of their teeth, while in Hawaii, only 13 percent fell into that category.

Utah reported the highest percentage (63.8) of adults with most of their natural teeth, while West Virginia reported the lowest (26.6 percent).

“When we see this wide variation, we really have to drill down to see what is this related to,” Gooch says. “That wasn’t the focus of this study, but we would certainly relate it to differences in health behavior and socioeconomic status.”

Higher education and income levels tended to translate into more teeth.

Only 31 percent of those with a high school education retained most of their teeth versus 46 percent to 64 percent of those with more education. Only 30 percent of those with household incomes of less than $15,000 had most of their teeth versus 41 percent to 73 percent of those with higher incomes.

Also, people with poorer general health as well as smokers tended to lose more teeth.

“Smoking is highly related to periodontal disease, which is related to tooth loss,” Gooch says. “Cigarette smoking accounts for about half of all cases of periodontal disease.”

Exposure to fluorides may be the single biggest explanation for the general improvement in oral health in this nation. Advances in dental techniques, better oral hygiene levels and self-care practices and improving socioeconomic status also play a role.

“Basically, all of these factors — but particularly exposure to fluoride — has resulted in increasing retention of teeth,” Gooch says.

The challenge now is to help older adults maintain good care of their teeth as they age. In that context, the relationship between poor overall health and tooth retention is a troubling one.

“If they’re reporting that they’re in poorer health, then they’re going to have difficulty getting to the dental office and tolerating treatment and maintaining self-care,” Gooch says. “We’re going to have to look in the future for innovative strategies for providing daily self-care and getting to the dental office.”

That message really applies to all adults, whether or not they are in poor health. “As adults and as older adults with teeth, we remain at risk for cavities,” Gooch says. “Not only should they be visiting the dentist on a regular basis but other strategies such as twice daily use of fluoride toothpaste and drinking fluoridated water will help in the prevention of tooth decay.”

Having teeth is its own reward. “Older people can eat a broader range of things because they can chew them, plus they have more self confidence because they’re not putting their teeth in a glass next to the bed at night,” Messina says.

More information

The American Dental Association has more on fluoride and fluoridation. The CDC has more on oral health.