Bad teeth, bleeding gums and poor dental hygiene can end up causing heart disease, scientists heard today (Thursday 11 September 2008) at the Society for General Microbiology's Autumn meeting being held this week at Trinity College, Dublin.
People with poor dental hygiene and those who don't brush their teeth regularly end up with bleeding gums, which provide an entry to the bloodstream for up to 700 different types of bacteria found in our mouths. This increases the risk of having a heart attack, according to microbiologists from the University of Bristol and the Royal College of Surgeons in Ireland.
"The mouth is probably the dirtiest place in the human body," said Dr Steve Kerrigan from the Royal College of Surgeons in Dublin, Ireland. "If you have an open blood vessel from bleeding gums, bacteria will gain entry to your bloodstream. When bacteria get into the bloodstream they encounter tiny fragments called platelets that clot blood when you get a cut. By sticking to the platelets bacteria cause them to clot inside the blood vessel, partially blocking it. This prevents the blood flow back to the heart and we run the risk of suffering a heart attack."
The only treatment for this type of disease is aggressive antibiotic therapy, but with the increasing problem of multiple drug resistant bacteria, this option is becoming short lived.
"Cardiovascular disease is currently the biggest killer in the western world. Oral bacteria such as Streptococcus gordonii and Streptococcus sanguinis are common infecting agents, and we now recognise that bacterial infections are an independent risk factor for heart diseases," said Professor Howard Jenkinson from the University of Bristol. "In other words it doesn't matter how fit, slim or healthy you are, you're adding to your chances of getting heart disease by having bad teeth."
Researchers at Bristol have been investigating the ways in which the bacteria interact with platelets in order to develop new and improved therapies.
"Most of the studies that have looked at how bacteria interact with platelets were carried out under conditions that do not resemble those in the human circulatory system. We mimicked the pressure inside the blood vessels and in the heart", said Professor Jenkinson. "Using this technique we demonstrated that bacteria use different mechanisms to cause platelets to clump together, allowing them to completely encase the bacteria. This shields the bacteria from the cells of our immune systems, which would normally kill bacteria, and most importantly also protects them from antibiotics."
These findings suggest why antibiotics do not always work in the treatment of infectious heart disease and also highlight the need to develop new drugs to treat this disease. "We are currently in the process of identifying the exact site at which the bacteria stick to the platelets," said Professor Jenkinson. "Once this is identified we will design a new drug to prevent this interaction."
"We also identified several proteins on the bacteria that lead to platelet clumping," said Dr Kerrigan. "Genetic deletion of these proteins from the bacteria prevented the platelets from clumping which shows that these proteins play an essential role and may be candidate proteins for new drug development or producing vaccines."
Thursday, September 11, 2008
Tuesday, September 9, 2008
Study Shows High Gum Disease Rates
Research on 445 families centered in two Pennsylvania towns and two West Virginia counties shows that 80 percent of adults suffer from more severe forms of periodontal disease, according to Richard Crout, D.M.D., Ph.D., an expert on gum disease and associate dean for research in the West Virginia University School of Dentistry.
“Leaving periodontal disease untreated is a major public health problem,” Crout says. “Not only do we see cases where the inflammatory process has eaten down around the bone, ultimately causing tooth loss in many patients, but also more important the inflammation likely has traveled throughout the body. A person with periodontitis may be twice as likely to have a heart attack and almost three times more likely to have a stroke.”
He added, “If a woman is pregnant, she is four to seven times more likely to have a preterm, low birth-weight baby compared to someone who does not have gum disease.”
Unlike gingivitis, an inflammation of the gums that is reversible, periodontitis can create infections below the gum line leading to bone destruction and tooth loss if not treated. Bleeding of the gums can signal gingivitis. But in periodontitis, no pain or symptoms may accompany the infection spreading into the bone.
Eighty-five percent of adults in the study showed signs of bone loss.
The study focusing on rural areas of Appalachia is a WVU-University of Pittsburgh collaboration, yielding a gold mine of dental data. Crout, who is directing the West Virginia portion of the collaboration, is sharing some of the more significant findings at the 94th Annual Meeting of the American Academy of Periodontology in Seattle Sept. 8. (The academy’s annual meeting runs Sept. 6 through 9.)
“This is the largest oral health study ever done in Appalachia,” Crout says.
In addition to dramatic rates of periodontal disease, discovery of high bacterial counts and the virulence of the disease-causing organisms in the mouth surprised the researchers, Crout says.
“These findings are significant in a state that leads the nation in all those who have lost all their teeth over the age of 65,” Crout says. “The national average is 20 percent, but in West Virginia, it’s 43 percent.”
The West Virginia families in the study live in Webster and Nicholas Counties. The Pennsylvania families are from the towns of Burgettstown and Bradford.
WVU’s portion of the National Institutes of Health grant is approximately $3.12 million. WVU researchers have followed the West Virginia families since 2002, studying genetic as well as environmental factors including attitudes, behaviors and beliefs. They are also examining microbial samples.
The study is part of COHRA – the Center for Oral Health Research in Appalachia. Originally involving only WVU and the University of Pittsburgh, the study has expanded to include the University of Michigan and the University of Iowa.
The researchers say parents and grandparents who have already lost their teeth are likely to transmit attitudes to the next generation. “Too often the attitude is, ‘Don’t worry, you’re going to lose them anyway,’ ” Crout says.
When Crout travels throughout West Virginia giving presentations to students on the importance of oral health, he sometimes meets schoolchildren who come up after the talk and say, “Hey, Mister, what’s this bump?” The child will crook a finger inside his cheek to offer a look, and Crout will observe a large, untreated abscess of the tooth.
A large abscess sometimes means the mouth can’t be numbed. So the child’s first visit to the dentist may end up being painful. Fear of pain may lead to a lifelong reluctance to visit the dentist.
“We have found that dental fear is highest in the very young. It may be one of the reasons that, by the age of 8, one-third of children have untreated dental decay in West Virginia,” Crout says. “One-third of West Virginians under age 35 have lost at least six permanent teeth. Our research has found that more than 25 percent of people would rather have a tooth out than have treatment done that might preserve the tooth. Fear was one of the main factors.”
Crout would like the study to lead to interventions such as introducing children to the dentist and the dentist’s chair at age 1 or when the first tooth comes in.
“It’s likely that at this age, treatment will be more preventive and provide a more positive first dental visit experience. This would go a long way in reducing fear and be very helpful in getting larger numbers of people to go to the dentist,” Crout says.
“It is also critically important to get the word out to our people in the state of the importance of oral health. Not only will it keep their teeth, but it will also be very important for good systemic health. Brushing, flossing and routine dental visits have never been more important,” Crout says.
“Leaving periodontal disease untreated is a major public health problem,” Crout says. “Not only do we see cases where the inflammatory process has eaten down around the bone, ultimately causing tooth loss in many patients, but also more important the inflammation likely has traveled throughout the body. A person with periodontitis may be twice as likely to have a heart attack and almost three times more likely to have a stroke.”
He added, “If a woman is pregnant, she is four to seven times more likely to have a preterm, low birth-weight baby compared to someone who does not have gum disease.”
Unlike gingivitis, an inflammation of the gums that is reversible, periodontitis can create infections below the gum line leading to bone destruction and tooth loss if not treated. Bleeding of the gums can signal gingivitis. But in periodontitis, no pain or symptoms may accompany the infection spreading into the bone.
Eighty-five percent of adults in the study showed signs of bone loss.
The study focusing on rural areas of Appalachia is a WVU-University of Pittsburgh collaboration, yielding a gold mine of dental data. Crout, who is directing the West Virginia portion of the collaboration, is sharing some of the more significant findings at the 94th Annual Meeting of the American Academy of Periodontology in Seattle Sept. 8. (The academy’s annual meeting runs Sept. 6 through 9.)
“This is the largest oral health study ever done in Appalachia,” Crout says.
In addition to dramatic rates of periodontal disease, discovery of high bacterial counts and the virulence of the disease-causing organisms in the mouth surprised the researchers, Crout says.
“These findings are significant in a state that leads the nation in all those who have lost all their teeth over the age of 65,” Crout says. “The national average is 20 percent, but in West Virginia, it’s 43 percent.”
The West Virginia families in the study live in Webster and Nicholas Counties. The Pennsylvania families are from the towns of Burgettstown and Bradford.
WVU’s portion of the National Institutes of Health grant is approximately $3.12 million. WVU researchers have followed the West Virginia families since 2002, studying genetic as well as environmental factors including attitudes, behaviors and beliefs. They are also examining microbial samples.
The study is part of COHRA – the Center for Oral Health Research in Appalachia. Originally involving only WVU and the University of Pittsburgh, the study has expanded to include the University of Michigan and the University of Iowa.
The researchers say parents and grandparents who have already lost their teeth are likely to transmit attitudes to the next generation. “Too often the attitude is, ‘Don’t worry, you’re going to lose them anyway,’ ” Crout says.
When Crout travels throughout West Virginia giving presentations to students on the importance of oral health, he sometimes meets schoolchildren who come up after the talk and say, “Hey, Mister, what’s this bump?” The child will crook a finger inside his cheek to offer a look, and Crout will observe a large, untreated abscess of the tooth.
A large abscess sometimes means the mouth can’t be numbed. So the child’s first visit to the dentist may end up being painful. Fear of pain may lead to a lifelong reluctance to visit the dentist.
“We have found that dental fear is highest in the very young. It may be one of the reasons that, by the age of 8, one-third of children have untreated dental decay in West Virginia,” Crout says. “One-third of West Virginians under age 35 have lost at least six permanent teeth. Our research has found that more than 25 percent of people would rather have a tooth out than have treatment done that might preserve the tooth. Fear was one of the main factors.”
Crout would like the study to lead to interventions such as introducing children to the dentist and the dentist’s chair at age 1 or when the first tooth comes in.
“It’s likely that at this age, treatment will be more preventive and provide a more positive first dental visit experience. This would go a long way in reducing fear and be very helpful in getting larger numbers of people to go to the dentist,” Crout says.
“It is also critically important to get the word out to our people in the state of the importance of oral health. Not only will it keep their teeth, but it will also be very important for good systemic health. Brushing, flossing and routine dental visits have never been more important,” Crout says.
Friday, September 5, 2008
Dental fillings without gaps
Tooth cavities are usually closed with plastic fillings. However, the initially soft plastic shrinks as it hardens. The tension can cause gaps to appear between the tooth and the filling, encouraging more caries to form. For the first time, researchers have simulated this process.
The patient’s hands are clasped firmly around the armrests as the dentist drills away the caries-stricken sections of the tooth. Once the drilling is over, most toothache sufferers can begin to relax. All the doctor now has to do is to slightly etch the cavity, apply an adhesive film, and fill it with a special type of plastic. The plastic is soft at first, so that the doctor can easily press it into the cavity. It only solidifies afterwards under the light of a small lamp. However, the material tends to shrink slightly as it hardens, occasionally producing tension that can cause tiny gaps to form between the plastic filling and the tooth. Bits of food can get caught in these gaps and lead to more caries. Manufacturers of filling materials therefore offer a variety of plastics to choose from. But which filling is best suited to which shape of cavity? This is where dentists have to draw on their experience. “Until now, it has not been possible to establish a theoretical model of the hardening process. The tension occurring in the material always depends on the shape of the cavity, and can vary widely by a factor of up to ten, particularly at the edges,” says Dr.-Ing. Christof Koplin, research assistant at the Fraunhofer Institute for Mechanics of Materials IWM in Freiburg. Measurements do not help either, as tension can only be measured selectively. Its precise course of development has never yet been observed.
A new method of simulation now enables tension in dental fillings to be accurately predicted, helping doctors to choose the least tension-prone plastic for each shape of cavity. Dentists can now draw on the results of the IWM to select the best material, and manufacturers can use the simulations to optimize their products. “We theoretically subdivide the dental filling into thousands of small parcels and calculate how each element affects its neighbor. Experimental parameters are incorporated in the individual elements. We started our laboratory tests by using a standard geometry to find out how each material reacts to the stresses that occur when the volume shrinks, and how the flow capability of the material changes as it hardens,” explains Koplin. The IWM researchers have now successfully simulated the development of tension in dental fillings for various cavity shapes and materials, and more will follow.
The patient’s hands are clasped firmly around the armrests as the dentist drills away the caries-stricken sections of the tooth. Once the drilling is over, most toothache sufferers can begin to relax. All the doctor now has to do is to slightly etch the cavity, apply an adhesive film, and fill it with a special type of plastic. The plastic is soft at first, so that the doctor can easily press it into the cavity. It only solidifies afterwards under the light of a small lamp. However, the material tends to shrink slightly as it hardens, occasionally producing tension that can cause tiny gaps to form between the plastic filling and the tooth. Bits of food can get caught in these gaps and lead to more caries. Manufacturers of filling materials therefore offer a variety of plastics to choose from. But which filling is best suited to which shape of cavity? This is where dentists have to draw on their experience. “Until now, it has not been possible to establish a theoretical model of the hardening process. The tension occurring in the material always depends on the shape of the cavity, and can vary widely by a factor of up to ten, particularly at the edges,” says Dr.-Ing. Christof Koplin, research assistant at the Fraunhofer Institute for Mechanics of Materials IWM in Freiburg. Measurements do not help either, as tension can only be measured selectively. Its precise course of development has never yet been observed.
A new method of simulation now enables tension in dental fillings to be accurately predicted, helping doctors to choose the least tension-prone plastic for each shape of cavity. Dentists can now draw on the results of the IWM to select the best material, and manufacturers can use the simulations to optimize their products. “We theoretically subdivide the dental filling into thousands of small parcels and calculate how each element affects its neighbor. Experimental parameters are incorporated in the individual elements. We started our laboratory tests by using a standard geometry to find out how each material reacts to the stresses that occur when the volume shrinks, and how the flow capability of the material changes as it hardens,” explains Koplin. The IWM researchers have now successfully simulated the development of tension in dental fillings for various cavity shapes and materials, and more will follow.
Tuesday, September 2, 2008
Diabetes and Obesity Linked to Periodontitis?
The University of Illinois at Chicago has received a two-year federal grant to continue a study on how periodontitis, an inflammatory disease of the tissues surrounding teeth, is linked to type 2 diabetes and obesity.
Dr. Keiko Watanabe of the UIC College of Dentistry has found that periodontitis accelerates the onset of insulin resistance in rats fed a high-fat diet. Her new research will determine how periodontitis affects diabetic complications in the retina, aorta and pancreas.
"The prevalence of type 2 diabetes has risen dramatically as the result of an increase in obesity caused by a high-fat diet, junk food and a sedentary lifestyle," said Watanabe, associate professor of periodontics. Although the association between obesity, type 2 diabetes and periodontitis is recognized, she said, the underlying causes remain poorly understood.
Watanabe said the goal of the new study is to identify the causes by which periodontitis influences insulin resistance, type 2 diabetes and organ damage, so clinicians will be able to screen prediabetic individuals at risk of developing the disease. A plan to treat periodontal inflammation will also be developed so that insulin resistance will not accelerate to diabetes.
A key challenge is to determine whether the relationship between diabetes, obesity and periodontitis is causal, Watanabe said. Most of the data linking the conditions are based on epidemiologic or cross-sectional studies, she said.
Watanabe uses female diabetic fatty rats in her research, a model that closely resembles humans who consume a high-fat diet and subsequently develop insulin resistance and type 2 diabetes. Human subjects, she said, cannot be used to study the direct effect of periodontitis because it is not ethical to induce the disease.
"Several prospective studies using human subjects demonstrated that the treatment of periodontitis led to improvement of glycemic control in subjects with type 2 diabetes," she said. "However, confounding factors, such as medications used to treat type 2 diabetes, body mass index, the stage and duration of diabetes, and the onset and severity of periodontitis are difficult to assess or are broadly controlled in such studies.
"Thus, the causal nature between periodontitis, diabetes and obesity remains unclear."
Diabetes is a disease in which the body fails to produce -- or responds poorly to -- insulin, a hormone needed to control the level of blood sugar. It is estimated that 300 million people worldwide will suffer from type 2 diabetes by the year 2025, nearly double the number of people affected in the year 2000. Most Americans diagnosed with diabetes have type 2, according to the American Diabetes Association.
Watanabe's initial study was published in the July issue of the Journal of Periodontology. The study was funded by a UIC College of Dentistry Research Seed Grant.
The new study, totaling $432,000, is being funded by the National Institute of Dental and Craniofacial Research, one of the National Institutes of Health. Dr. Terry Unterman, professor of medicine, physiology and biophysics, and Haohua Qian, associate professor of ophthalmology, will collaborate on the project.
Dr. Keiko Watanabe of the UIC College of Dentistry has found that periodontitis accelerates the onset of insulin resistance in rats fed a high-fat diet. Her new research will determine how periodontitis affects diabetic complications in the retina, aorta and pancreas.
"The prevalence of type 2 diabetes has risen dramatically as the result of an increase in obesity caused by a high-fat diet, junk food and a sedentary lifestyle," said Watanabe, associate professor of periodontics. Although the association between obesity, type 2 diabetes and periodontitis is recognized, she said, the underlying causes remain poorly understood.
Watanabe said the goal of the new study is to identify the causes by which periodontitis influences insulin resistance, type 2 diabetes and organ damage, so clinicians will be able to screen prediabetic individuals at risk of developing the disease. A plan to treat periodontal inflammation will also be developed so that insulin resistance will not accelerate to diabetes.
A key challenge is to determine whether the relationship between diabetes, obesity and periodontitis is causal, Watanabe said. Most of the data linking the conditions are based on epidemiologic or cross-sectional studies, she said.
Watanabe uses female diabetic fatty rats in her research, a model that closely resembles humans who consume a high-fat diet and subsequently develop insulin resistance and type 2 diabetes. Human subjects, she said, cannot be used to study the direct effect of periodontitis because it is not ethical to induce the disease.
"Several prospective studies using human subjects demonstrated that the treatment of periodontitis led to improvement of glycemic control in subjects with type 2 diabetes," she said. "However, confounding factors, such as medications used to treat type 2 diabetes, body mass index, the stage and duration of diabetes, and the onset and severity of periodontitis are difficult to assess or are broadly controlled in such studies.
"Thus, the causal nature between periodontitis, diabetes and obesity remains unclear."
Diabetes is a disease in which the body fails to produce -- or responds poorly to -- insulin, a hormone needed to control the level of blood sugar. It is estimated that 300 million people worldwide will suffer from type 2 diabetes by the year 2025, nearly double the number of people affected in the year 2000. Most Americans diagnosed with diabetes have type 2, according to the American Diabetes Association.
Watanabe's initial study was published in the July issue of the Journal of Periodontology. The study was funded by a UIC College of Dentistry Research Seed Grant.
The new study, totaling $432,000, is being funded by the National Institute of Dental and Craniofacial Research, one of the National Institutes of Health. Dr. Terry Unterman, professor of medicine, physiology and biophysics, and Haohua Qian, associate professor of ophthalmology, will collaborate on the project.
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.
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.
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.
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.
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