Monday, August 25, 2008

Immigrants respond best to oral hygiene campaign

Tapping into the desire to have an attractive smile is the best motivator for improving oral hygiene, and new immigrants are the most receptive to oral health messages, according to a new study in the Journal of Consumer Research.

Authors Shuili Du (Simmons College), Sankar Sen (City University of New York), and C.B. Bhattacharya (Boston University) evaluated the effectiveness of an oral health outreach program in disadvantaged communities. They found that focusing on the social benefits of having a beautiful smile was the most effective strategy for improving dental hygiene habits among participants.

"Our findings suggest that, among children from less acculturated families, participation in this oral health program leads to not only more favorable beliefs about the health-related (preventing cavities and gum diseases) and psychosocial (beautiful smile and self-confidence) benefits of oral care behavior, but also an increase in oral care behavior such as brushing, flossing and dental checkups," write the authors.

The research found that families that had been in the United States longer were less responsive to the program's messages than new immigrants.

According to the U.S. Department of Health and Human Services (2002), there is a "silent epidemic" of dental and oral diseases in disadvantaged communities, particularly among children of minority racial and ethnic groups. The researchers conducted focus groups of participants in urban areas with large Hispanic populations. Those participants were parents of children in the national oral health outreach program that was launched in 2000, with the involvement of a corporate sponsor, the Boys and Girls Club of America, the American Dental Association, and dental schools.

And here's good news for the corporate sponsor: the parents who participated in the program said they intended to reciprocate by purchasing the sponsor's products. "Their intention to reciprocate toward the company is proportionate to their perceptions of how much the program has helped their children and family," the researchers conclude.

Seeing through tooth decay

X-ray spectral analysis reveals early-stage dental caries

Dental caries afflict at least 90% of the world's population at some time in their lives. Detecting the first signs of this disease, which can be lethal in extreme cases, just got easier thanks to work by researchers in India discussed in the latest issue of the International Journal of Biomedical Engineering and Technology.

R. Siva Kumar of the Department of Electronics and Communication Engineering, at RMK Engineering College, in Tamil Nadu, explains that dental caries, known colloquially as tooth decay or dental cavities, is an infectious disease which damages the structures of teeth. The disease causes toothache, tooth loss, infection of the jawbone and beyond, and in severe cases, death.

Caries are caused by acid-producing bacteria that feed on fermentable carbohydrates including sucrose, fruit sugars, and glucose. The higher level of acidity in the mouth due to this bacterial activity effectively dissolves the mineral content of the tooth. In the USA, dental caries is the most common chronic childhood disease, being at least five times more common than asthma. It is the primary cause of tooth loss in children, while between a third and two thirds of people over 50 years experience caries too.

There are two types of dental caries, those that form on the smooth surfaces of the teeth and those in the pits and fissures. The latter are difficult to detect visually or manually with a dental explorer. Detecting caries in the early stages of development is important for saving affected teeth and avoiding the possibility of tooth loss and invasive surgery at later stages. Siva Kumar suggests that X-rays of a patient's teeth analyzed by specialist software could help.

The researchers at RMK engineering college have now developed an X-ray image analysis technique that reveals the pixel intensities at different X-ray wavelengths, much like the histogram analysis of images by a high-specification digital camera. Siva Kumar explains that the software reveals that the X-ray histogram and spectrum are very different depending on whether the teeth X-rayed are normal or exhibiting the early stages of decay. The researchers found that in the X-ray histogram the pixel intensities are concentrated in different ranges depending on degree of decay.

The technique could be very useful for dental clinicians, the researchers explain, and could be extended using neural networks to automatically identify the different stages of dental caries.

Friday, August 8, 2008

Periodontal disease predicts new onset diabetes

Periodontal disease may be an independent predictor of incident Type 2 diabetes, according to a study by researchers at Columbia University Mailman School of Public Health. While diabetes has long been believed to be a risk factor for periodontal infections, this is the first study exploring whether the reverse might also be true, that is, if periodontal infections can contribute to the development of diabetes. The full study findings are published in the July 2008 issue of Diabetes Care.

The Mailman School of Public Health researchers studied over 9,000 participants without diabetes from a nationally representative sample of the U.S. population, 817 of whom went on to develop diabetes. They then compared the risk of developing diabetes over the next 20 years between people with varying degrees of periodontal disease and found that individuals with elevated levels of periodontal disease were nearly twice as likely to become diabetic in that 20 year timeframe. These findings remained after extensive multivariable adjustment for potential confounders including, but not limited to, age, smoking, obesity, hypertension, and dietary patterns.

"These data add a new twist to the association and suggest that periodontal disease may be there before diabetes," said Ryan T. Demmer, PhD, MPH, associate research scientist in the Department of Epidemiology at the Mailman School of Public Health and lead author. "We found that over two decades of follow-up, individuals who had periodontal disease were more likely to develop Type 2 diabetes later in life when compared to individuals without periodontal disease."

Also of interest, the researchers found that those study participants who had lost all of their teeth were at intermediate risk for incident diabetes. "This could be suggestive that the people who lost all of their teeth had a history of infection at some point, but subsequently lost their teeth and removed the source of infection," noted Dr. Demmer. "This is particularly interesting as it supports previous research originating from The Oral Infections and Vascular Disease Epidemiology Study (INVEST) which has shown that individuals lacking teeth are at intermediate risk for cardiovascular disease" said Moïse Desvarieux, MD, PhD, director of INVEST, associate professor and Inserm Chair of Excellence in the Department of Epidemiology at the Mailman School and senior author of the paper.

The contributory role of periodontal disease in the development of Type 2 diabetes is potentially of public health importance because of the prevalence of treatable periodontal diseases in the population and the pervasiveness of diabetes-associated morbidity and mortality. However, observes Dr. Demmer, more studies are needed both to determine whether gum disease directly contributes to type 2 diabetes and, from there, that treating the dental problem can prevent diabetes. In addition to Dr. Desvarieux, David R. Jacobs Jr., PhD, professor in the Department of Epidemiology and Community Health at the University of Minnesota, also contributed to the research.