Brushing your teeth could prevent heart disease

Prospective study finds clinically significant difference in atherosclerosis progression based on changes in periodontal health

Taking care of your gums by brushing, flossing, and regular dental visits could help hold heart disease at bay. Researchers at Columbia University's Mailman School of Public Health have shown for the first time that as gum health improves, progression of atherosclerosis slows to a clinically significant degree. Findings appear online in the Journal of the American Heart Association.

Artherosclerosis, or the narrowing of arteries through the build-up of plaque, is a major risk factor for heart disease, stroke, and death.

"These results are important because atherosclerosis progressed in parallel with both clinical periodontal disease and the bacterial profiles in the gums. This is the most direct evidence yet that modifying the periodontal bacterial profile could play a role in preventing or slowing both diseases," says Moïse Desvarieux, MD, PhD, lead author of the paper and associate professor of Epidemiology at the Mailman School.

The researchers followed 420 adults as part of the Oral Infections and Vascular Disease Epidemiology Study (INVEST), a randomly sampled prospective cohort of Northern Manhattan residents. Participants were examined for periodontal infection. Overall, 5,008 plaque samples were taken from several teeth, beneath the gum, and analyzed for 11 bacterial strains linked to periodontal disease and seven control bacteria. Fluid around the gums was sampled to assess levels of Interleukin-1β, a marker of inflammation. Atherosclerosis in both carotid arteries was measured using high-resolution ultrasound.

Over a median follow-up period of three years, the researchers found that improvement in periodontal health—health of the gums—and a reduction in the proportion of specific bacteria linked to periodontal disease correlated to a slower intima-medial thickness (IMT) progression, and worsening periodontal infections paralleled the progression of IMT. Results were adjusted for potential confounders such as body mass index, cholesterol levels, diabetes, and smoking status,

Clinical Significance

There was a 0.1 mm difference in IMT change over three years among study participants whose periodontal health was deteriorating compared with those whose periodontal health was improving. Previous research has shown that a .033 mm/year increase in carotid IMT (equivalent to approximately 0.1 mm over three years) is associated with a 2.3-fold increased risk for coronary events.

"When it comes to atherosclerosis, a tenth of a millimeter in the thickness of the carotid artery is a big deal. Based on prior research, it appears to meet the threshold of clinical significance," says Tatjana Rundek, MD, PhD, a co-author of the study and professor at the University of Miami whose lab read the carotid ultrasounds.

Even subtle changes to periodontal status had a dose-response relationship to carotid IMT. "Our results show a clear relationship between what is happening in the mouth and thickening of the carotid artery, even before the onset of full-fledged periodontal disease," says co-author Panos N. Papapanou, DDS, PhD, professor of Dental Medicine at Columbia University's College of Dental Medicine, whose laboratory assessed the bacterial profiles in the gums. "This suggests that incipient periodontal disease should not be ignored."

Bacteria in the mouth may contribute to the onset of atherosclerosis in a number of ways, scientists speculate. Animal studies indicate that they may trigger immune response and high levels of inflammatory markers, which may initiate or exacerbate the inflammatory aspect of atherosclerosis.

The results build on previous findings. In earlier cross-sectional results, Dr. Desvarieux and colleagues had reported that higher levels of disease-causing bacteria were associated with thicker IMT. The current study takes the next step by looking at the cohort over time.

"Our results address a gap identified in the AHA statement on periodontal disease and atherosclerosis, by providing longitudinal data supporting this association," says study co-author Ralph Sacco, MD, professor and chairman of Neurology at the University of Miami, Miller School of Medicine and former president of the American Heart Association. Concludes Dr. Desvarieux, "It is critical that we continue to follow these patients to see if the relationship between periodontal infections and atherosclerosis carries over to clinical events like heart attack and stroke and test if modifying the periodontal flora will slow the progression of atherosclerosis."

Burning Mouth Syndrome Is Often Difficult to Diagnose

Oral pain that feels like a scalded mouth and can last for months has baffled dental researchers since the 1970s, when burning oral sensations were linked to mucosal, periodontal, and restorative disorders and mental or emotional causes.

It’s called burning mouth syndrome (BMS), and it’s gaining the attention of such dental researchers as oral pain expert Andres Pinto, who recently joined Case Western Reserve University’s School of Dental Medicine faculty.

What’s frustrates patients and doctors alike, said Pinto, is that the mouth and gums appear normal with BMS, so its diagnosis is difficult. Patients often find themselves having to visit several doctors before finally arriving at BMS as the cause.

Pinto, new chair and associate professor in the Department of Oral Diagnosis and Radiology at the dental school and an oral medical specialist in the Department of Oral and Maxillofacial Surgery at UH Case Medical Center, encourages people with persistent mouth pain to check for the following symptoms that might be caused by BMS:

• Persistent burning tongue and oral pain with no apparent dental cause
• Abnormal taste or dry feeling in the mouth
• Symptoms that disappear when eating
• Burning sensations may migrate across several oral areas

Even if oral pain is present without these symptoms, Pinto recommended consulting a dentist for a thorough exam of the teeth, gums, mouth and throat.

Between two and five percent of the U.S. population acquires BMS, he said, but the syndrome especially strikes women between age 50 and 70, and from three years before to 12 years after menopause.

Early research in BMS explored the association with local oral changes that could be corrected by dentists, and the observed comorbidity with psychogenic disorders. Changes in neurologic sensory function in patients with BMS and reported cases of secondary BMS to anemia, diabetes, vitamin deficiency, and thyroid disorders, triggered further exploration into peripheral neural changes and central nervous system (brain) mechanisms that could contribute to the causes of this condition.

Although the exact cause of BMS is unknown, the suspected origin is deterioration of the nerves beneath the oral lining. The deterioration isn’t visible, which explains why the mouth appears normal when examined and can delay diagnosis, Pinto explained. Still unproven is the role hormones may play in BMS, given the link to menopause.

The pain from BMS often results in quality of life issues, from poor nutrition to the sufferer withdrawing from social situations. In some cases, the pain is so severe it has driven people to commit suicide, Pinto said.

Patients can receive relief with special mouthwashes, analgesics and other topical and systemic treatments.

Pinto recently joined a research team to learn what postgraduate programs in dental schools are teaching about BMS. The researchers report in the October issue of the Journal of the American Dental Association that BMS is being taught but more needs to be done.

Olympians say poor oral health is impairing performance

Many of the elite sportsmen and women who competed at the London 2012 Olympic Games had poor levels of oral health similar to those experienced by the most disadvantaged populations. 18 per cent of athletes surveyed said their oral health was having a negative impact on their performance.

The research, which was led by Professor Ian Needleman at the UCL Eastman Dental Institute, is published in the British Journal of Sports Medicine.

The researchers recruited 302 athletes to take part in the study at the Dental Clinic in the London 2012 athletes' village. The athletes represented 25 different sports, with 95 (34.9 per cent) competing in track and field, 38 (14 per cent) boxing and 31 (11.4 per cent) playing hockey. The athletes were given a systematic oral health check-up before being asked to give a personal assessment of the impact of oral health on their quality of life and athletic training/performance.

Overall, the research team found high levels of poor oral health with 55 per cent of athletes suffering from dental caries (tooth decay), of which 41 per cent was into the dentine (and therefore irreversible). More than three quarters of the participants had gingivitis (early stage gum disease) with 15 per cent showing signs of periodontitis, an irreversible gum infection in the soft tissue around the teeth.

42 per cent of athletes taking part in the study said that they were, "bothered by oral health" issues, with 28 per cent saying that it affected their quality of life. Almost one in five (18 per cent) athletes said that they believed poor oral health was negatively affecting their training or performance levels.

Nearly half of participants (46.5 per cent) had not attended for a dental examination or hygiene care in the previous year, while 8.7 per cent said they had never been to the dentist.

Professor Ian Needleman, lead author of the paper at the UCL Eastman Dental Institute, said: "Oral health is important for wellbeing and successful elite sporting performance. It is amazing that many professional athletes – people who dedicate a huge amount of time and energy to honing their physical abilities – do not have sufficient support for their oral health needs, even though this negatively impacts on their training and performance.

"Oral health assessment should be part of every athlete's routine medical care," continues Professor Needleman. "If we are going to help them optimise their level of performance we need to concentrate on oral health promotion and disease prevention strategies to facilitate the health and wellbeing of all our elite athletes."

In the report the authors speculate that the associations between oral health, wellbeing and performance might be explained by oral disease causing pain, systemic inflammation and a reduction in self-confidence and quality of life.

Previous studies have repeatedly found athletes to have poor oral health, something which might result from frequent carbohydrate intake, a reduced immune function through intensive training and a lack of awareness about the links between oral health and elite performance.

Are nanodiamond-encrusted teeth the future of dental implants?

UCLA researchers have discovered that diamonds on a much, much smaller scale than those used in jewelry could be used to promote bone growth and the durability of dental implants.

Nanodiamonds, which are created as byproducts of conventional mining and refining operations, are approximately four to five nanometers in diameter and are shaped like tiny soccer balls. Scientists from the UCLA School of Dentistry, the UCLA Department of Bioengineering and Northwestern University, along with collaborators at the NanoCarbon Research Institute in Japan, may have found a way to use them to improve bone growth and combat osteonecrosis, a potentially debilitating disease in which bones break down due to reduced blood flow.

When osteonecrosis affects the jaw, it can prevent people from eating and speaking; when it occurs near joints, it can restrict or preclude movement. Bone loss also occurs next to implants such as prosthetic joints or teeth, which leads to the implants becoming loose — or failing.

Implant failures necessitate additional procedures, which can be painful and expensive, and can jeopardize the function the patient had gained with an implant. These challenges are exacerbated when the disease occurs in the mouth, where there is a limited supply of local bone that can be used to secure the prosthetic tooth, a key consideration for both functional and aesthetic reasons.

The study, led by Dr. Dean Ho, professor of oral biology and medicine and co-director of the Jane and Jerry Weintraub Center for Reconstructive Biotechnology at the UCLA School of Dentistry, appears online in the peer-reviewed Journal of Dental Research.

During bone repair operations, which are typically costly and time-consuming, doctors insert a sponge through invasive surgery to locally administer proteins that promote bone growth, such as bone morphogenic protein.

Ho's team discovered that using nanodiamonds to deliver these proteins has the potential to be more effective than the conventional approaches. The study found that nanodiamonds, which are invisible to the human eye, bind rapidly to both bone morphogenetic protein and fibroblast growth factor, demonstrating that the proteins can be simultaneously delivered using one vehicle. The unique surface of the diamonds allows the proteins to be delivered more slowly, which may allow the affected area to be treated for a longer period of time. Furthermore, the nanodiamonds can be administered non-invasively, such as by an injection or an oral rinse.

"We've conducted several comprehensive studies, in both cells and animal models, looking at the safety of the nanodiamond particles," said Laura Moore, the first author of the study and an M.D.-Ph.D. student at Northwestern University under the mentorship of Dr. Ho. "Initial studies indicate that they are well tolerated, which further increases their potential in dental and bone repair applications."

"Nanodiamonds are versatile platforms," said Ho, who is also professor of bioengineering and a member of the Jonsson Comprehensive Cancer Center and the California NanoSystems Institute. "Because they are useful for delivering such a broad range of therapies, nanodiamonds have the potential to impact several other facets of oral, maxillofacial and orthopedic surgery, as well as regenerative medicine."

Ho's team previously showed that nanodiamonds in preclinical models were effective at treating multiple forms of cancer. Because osteonecrosis can be a side effect of chemotherapy, the group decided to examine whether nanodiamonds might help treat the bone loss as well. Results from the new study could open the door for this versatile material to be used to address multiple challenges in drug delivery, regenerative medicine and other fields.

"This discovery serves as a foundation for the future of nanotechnology in dentistry, orthopedics and other domains in medicine," said Dr. No-Hee Park, dean of the School of Dentistry. "Dr. Ho and his team have demonstrated the enormous potential of the nanodiamonds toward improving patient care. He is a pioneer in his field."

Bacteria responsible for gum disease facilitates development and progression of rheumatoid arthritis

Does gum disease indicate future joint problems? Although researchers and clinicians have long known about an association between two prevalent chronic inflammatory diseases - periodontal disease and rheumatoid arthritis (RA) - the microbiological mechanisms have remained unclear.

In an article published today in PLoS Pathogens, University of Louisville School of Dentistry Oral Health and Systemic Diseases group researcher Jan Potempa, PhD, DSc, and an international team of scientists from the European Union’s Gums and Joints project have uncovered how the bacterium responsible for periodontal disease, Porphyromonas gingivalis worsens RA by leading to earlier onset, faster progression and greater severity of the disease, including increased bone and cartilage destruction.

The scientists found that P. gingivalis produces a unique enzyme, peptidylarginine deiminanse (PAD) which then enhances collagen-induced arthritis (CIA), a form of arthritis similar to RA produced in the lab. PAD changes residues of certain proteins into citrulline, and the body recognizes citullinated proteins as intruders, leading to an immune attack. In RA patients, the subsequent result is chronic inflammation responsible for bone and cartilage destruction within the joints.

Potempa and his team studied another oral bacterium, Prevotella intermedia for the same affect, but learned it did not produce PAD, and did not affect CIA.

“Taken together, our results suggest that bacterial PAD may constitute the mechanistic link between P. gingivalis periodontal infection and rheumatoid arthritis, but this ground-breaking conclusion will need to be verified with further research,” he said.

Potempa said he is hopeful these findings will shed new light on the treatment and prevention of RA.

Studies indicate that compared to the general population, people with periodontal disease have an increased prevalence of RA and, periodontal disease is at least two times more prevalent in RA patients. Other research has shown that a P. gingivalis infection in the mouth will precede RA, and the bacterium is the likely culprit for onset and continuation of the autoimmune inflammatory responses that occur in the disease.

Expectant mothers' periodontal health vital to health of her baby

When a woman becomes pregnant, she knows it is important to maintain a healthy lifestyle to ensure both the health of herself and the health of her baby. New clinical recommendations from the American Academy of Periodontology (AAP) and the Eurpean Federation of Periodontology (EFP) urge pregnant women to maintain periodontal health as well. Research has indicated that women with periodontal disease may be at risk of adverse pregnancy outcomes, such giving birth to a pre-term or low-birth weight baby, reports the AAP and EFP.

Periodontal disease is a chronic, bacteria-induced, inflammatory condition that attacks the gum tissue and in more severe cases, the bone supporting the teeth. If left untreated, periodontal disease, also known as gum disease, can lead to tooth loss and has been associated with other systemic diseases, such as diabetes and cardiovascular disease.

"Tenderness, redness, or swollen gums are a few indications of periodontonal disease," warns Dr. Nancy L. Newhouse, DDS, MS, President of the AAP and a practicing periodontist in Independence, Missouri. "Other symptoms include gums that bleed with toothbrushing or eating, gums that are pulling away from the teeth, bad breath, and loose teeth. These signs, especially during pregnancy, should not be ignored and may require treatment from a dental professional."

Several research studies have suggested that women with periodontal disease may be more likely to deliver babies prematurely or with low-birth weight than mothers with healthy gums. According to the Center for Disease Control and Prevention (CDC), babies with a birth weight of less than 5.5 pounds may be at risk of long-term health problems such as delayed motor skills, social growth, or learning disabilities. Similar complications are true for babies born at least three weeks earlier than its due date. Other issues associated with pre-term birth include respiratory problems, vision and hearing loss, or feeding and digestive problems.

The medical and dental communities concur that maintaining periodontal health is an important part of a healthy pregnancy. The clinical recommendations released by the AAP and the EFP state that non-surgical periodontal therapy is safe for pregnant women, and can result in improved periodontal health. Published concurrently in the Journal of Periodontology and Journal of Clinical Periodontology, the report provides guidelines for both dental and medical professionals to use in diagnosing and treating periodontal disease in pregnant women. In addition, the American College of Obstetricians and Gynecologists recently released a statement encouraging pregnant women to sustain their oral health and recommended regular dental cleanings during pregnancy.

"Routine brushing and flossing, and seeing a periodontist, dentist, or dental hygienist for a comprehensive periodontal evaluation during pregnancy may decrease the chance of adverse pregnancy complications," says Dr. Newhouse. "It is important for expectant mothers to monitor their periodontal health and to have a conversation with their periodontist or dentist about the most appropriate care. By maintaining your periodontal health, you are not only supporting your overall health, but also helping to ensure a safe pregnancy and a healthy baby," says Dr. Newhouse.

Poor oral health linked to cancer-causing oral HPV infection

Poor oral health, including gum disease and dental problems, was found to be associated with oral human papillomavirus (HPV) infection, which causes about 40 percent to 80 percent of oropharyngeal cancers, according to a study published in Cancer Prevention Research, a journal of the American Association for Cancer Research.

"Poor oral health is a new independent risk factor for oral HPV infection and, to our knowledge, this is the first study to examine this association," said Thanh Cong Bui, Dr.P.H., postdoctoral research fellow in the School of Public Health at the University of Texas Health Sciences Center in Houston. "The good news is, this risk factor is modifiable — by maintaining good oral hygiene and good oral health, one can prevent HPV infection and subsequent HPV-related cancers."

The researchers found that among the study participants, those who reported poor oral health had a 56 percent higher prevalence of oral HPV infection, and those who had gum disease and dental problems had a 51 percent and 28 percent higher prevalence of oral HPV infection, respectively. In addition, the researchers were able to associate oral HPV infections with number of teeth lost.

Similar to genital HPV infection, oral HPV infection can be of two kinds: infection with low-risk HPV types that do not cause cancer, but can cause a variety of benign tumors or warts in the oral cavity, and infection with high-risk HPV types that can cause oropharyngeal cancers.

Bui, Christine Markham, Ph.D., and colleagues used data from the 2009-2010 National Health and Nutrition Examination Survey (NHANES) conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. This survey consisted of a nationally representative sample of about 5,000 people recruited each year, located in counties across the United States.

The researchers identified 3,439 participants aged 30 to 69 years from NHANES, for whom data on oral health and the presence or absence of 19 low-risk HPV types and 18 high-risk HPV types in the oral cavity were available. Oral health data included four measures of oral health: self-rating of overall oral health, presence of gum disease, use of mouthwash to treat dental problems within past seven days of the survey, and number of teeth lost. They examined data on age, gender, marital status, marijuana use, cigarette smoking, and oral sex habits, among others, which influence HPV infection.

The researchers found that being male, smoking cigarettes, using marijuana, and oral sex habits increased the likelihood of oral HPV infection. They also found that self-rated overall oral health was an independent risk factor for oral HPV infection, because this association did not change regardless of whether or not the participants smoked or had multiple oral sex partners.

Because HPV needs wounds in the mouth to enter and infect the oral cavity, poor oral health, which may include ulcers, mucosal disruption, or chronic inflammation, may create an entry portal for HPV, said Bui. There is, however, currently not enough evidence to support this, and further research is needed to understand this relationship, he said.

"Although more research is needed to confirm the causal relationship between oral health and oral HPV infection, people may want to maintain good oral health for a variety of health benefits," said Bui. "Oral hygiene is fundamental for oral health, so good oral hygiene practices should become a personal habit."