Classifying gum disease genetically could help earlier diagnosis and treatment

A study published in the Journal of Dental Research suggests a new system for classifying periodontal disease that may allow for earlier detection and personalized treatment before the disease becomes severe.

The researchers propose a new classification system – the first of its kind – based on the genetic expression of gum diseaseinstead of the current method based on clinical signs and symptoms.

They say such a system would enable earlier detection of gum disease, and allow individualized treatment, before teeth and bone loss sets in.

The present system, based on clinical symptoms, classifies periodontal disease as either “chronic” or “aggressive” depending on how swollen the gum is and how much bone is lost.

However, lead researcher, Panos N. Papapanou, professor and chair of oral and diagnostic sciences at the College of Dental Medicine at Columbia University Medical Center New York, NY, explains the problem with it:

“… there is much overlap between the two classes. Many patients with severe symptoms can be effectively treated, while others with seemingly less severe infection may continue to lose support around their teeth even after therapy.”

He says the problem is they cannot really tell when the gum infection is truly aggressive until the damage is severe and irreversible.

Researchers inspired by how genetic signatures are used to classify tumors

Spurred by the need for a better way to classify gum disease, the researchers looked at the recent changes to the way cancer is diagnosed.

Biologists are increasingly finding markers for cancer aggressiveness and responsiveness in the genetic signatures of tumors, and these are beginning to be used successfully to classify and select appropriate treatment for individual patients.

To establish whether such a model might work for gum disease, the researchers carried out a genome-wide analysis of diseased gum (gingival) tissue from 120 male and female patients aged from 11 to 76, diagnosed with either chronic or aggressive periodontitis.

They found each patient belonged to one of two clusters, depending on the genetic signature they found of their gum disease. Moreover, they found the two clusters did not align with the two classes of the current system based on symptoms, but they did differ with respect to extent and severity of the disease.

The patients whose gene signature put them in cluster 2 had much more serious gum disease.

Cluster 2 also contained patients with higher levels of infection of known oral pathogens, and there were more male than female patients in this cluster compared with cluster 1. This was in keeping with what we know about severe gum disease – that it is more common in men than women.

Molecular profiling could be basis of new system for classifying gum disease

Prof. Papapanou says the results indicate that molecular profiling offers a basis for a new classification system based on disease pathology that correlates well with how the disease presents clinically.

The new system could help spot patients with severe gum disease that has not yet shown clinical signs, he explains:

“If a patient is found to be highly susceptible to severe periodontitis, we would be justified in using aggressive therapies, even though that person may have subclinical disease. Now, we wait years to make this determination, and by then, significant damage to the tooth-supporting structures may have occurred.”

He and his team now want to carry out a study where they use the new classification system with a group of patients that they follow to see how well it predicts disease outcomes.

They also want to find a way to typify the two clusters with biomarkers instead of genes, because they would be much easier to look for (for instance by analyzing molecules present in gum samples) than having to perform genome-wide tests on each patient.

Medical News Today recently learned of a paper published in the Australian Dental Journal that exploredepigenetics and oral health. There, researchers from the University of Adelaide’s School of Dentistry, say epigenetics has much to offer in the future treatment and prevention of dental disease, and predict that one day a visit to the dentist may well involve looking at how the patient’s genes are being switched on and off.

Written by Catharine Paddock PhD

http://www.medicalnewstoday.com/articles/274458.php

 

 

Getting Teeth Pulled Before Heart Surgery May Pose Serious Risks

THURSDAY, Feb. 27, 2014 (HealthDay News) — If you’re a heart patient, you might be wise to wait to have any infected teeth pulled if you’re about to have cardiac surgery, a new study suggests.

In a small, retrospective study, Mayo Clinic researchers found that 8 percent of heart patients who did not wait to have teeth pulled suffered major adverse health outcomes, such as a heart attack, stroke, kidney failure or death.

“Guidelines from the American College of Cardiology and American Heart Association label dental extraction as a minor procedure, with the risk of death or non-fatal heart attack estimated to be less than 1 percent,” study co-author Dr. Mark Smith said in a statement. “Our results, however, documented a higher rate of major adverse outcomes [with the extractions].”

Such extractions are commonly done ahead of some types of heart surgery to lower the chances of infection during the procedure or avoid inflammation of the inner layer of the heart after the operation, the researchers noted.

However, the study didn’t pinpoint what risks might be posed by postponing major dental care until after heart surgery. The study also didn’t prove a cause-and-effect relationship.

Still, the finding “does help us to understand the risk we’re exposing patients to when they get their teeth extracted before their heart surgery,” said study co-author Dr. Kendra Grim, an anesthesiologist at the Mayo Clinic in Rochester, Minn. “It opens up a lot of different avenues for research and discussion.”

At issue is what to do with patients who have both dental problems and heart issues. A combination of these two conditions isn’t uncommon, explained Dr. Ann Bolger, a professor of medicine at the University of California, San Francisco, and a spokeswoman for the American Heart Association.

“Given the frequency of risk factors that poor oral health and cardiovascular disease share, such as age, smoking and diabetes, the fact that they overlap is not a surprise,” Bolger said.

But the combination can be dangerous.

“We know that patients with poor dental health are at higher risk of having bacteria in the bloodstream, which can cause infections in the heart valve,” Grim explained.

Previous research suggests that patients with infected artificial heart valves have a 38 percent higher risk of dying, according to background information in the study.

Surgeons may recommend dental care before heart valve surgery and other kinds of cardiac surgery, such as coronary artery bypass procedures and heart transplants.

But the authors of the new study write that it’s not clear whether it’s a good idea to get dental treatment before heart surgery. To try to get closer to an answer, they examined the medical records of 205 patients who had teeth removed before undergoing cardiac surgery.

Of those patients, a total of 8 percent (16 people) experienced a heart attack, stroke, kidney failure or death. Twelve patients died within 30 days after their teeth were removed — including six people who died before their cardiac operation and six who died after heart surgery, the investigators found.

What’s going on?

The condition of the patients may have been so poor that they had trouble tolerating anesthesia during a dental procedure, Grim said. As to whether things would have been different if patients hadn’t undergone dental treatment, Grim said it’s unclear.

Still, the risk of death and other medical problems was higher than the study authors expected, she noted.

“If a tooth is painful and obviously infected, it must be dealt with,” Grim said. “The dental procedures discussed here, and that are most common, are prophylactic [preventive]. That is, the extraction of an infected tooth may not be an urgent dental issue, but when the patient has [scheduled] heart surgery — particularly valve replacement surgery — pre-emptive dental imaging and extractions are often performed.”

For now, the study isn’t prompting any new guidelines or rules. For one, researchers don’t know exactly where the increased risk may originate. It’s not easy to figure out what to do except carefully control pain or high blood pressure resulting from a dental procedure, Bolger said.

“This is an interesting study that identifies a gap in our understanding of the risks of this practice. But it does not prove that doing the opposite would improve outcomes,” Bolger said. “This work will need to be followed by additional studies before we know with more certainty.”

The study appears in the March issue of The Annals of Thoracic Surgery.

More information

For more about dental and heart health, try the American Heart Association.

http://news.health.com/2014/02/27/getting-teeth-pulled-before-heart-surgery-may-pose-serious-risks/