Thursday, February 27, 2014
Patients with dental extractions before cardiac surgery still at risk for poor outcomes, study finds
To pull or not to pull? That is a common question when patients have the potentially dangerous combination of abscessed or infected teeth and the need for heart surgery. In such cases, problem teeth often are removed before surgery, to reduce the risk of infections including endocarditis, an infection of the inner lining of the heart that can prove deadly. But Mayo Clinic research suggests it may not be as simple as pulling teeth: The study found that roughly 1 in 10 heart surgery patients who had troublesome teeth extracted before surgery died or had adverse outcomes such as a stroke or kidney failure.
The findings are published in The Annals of Thoracic Surgery.
Prosthetic heart valve-related endocarditis accounts for up to one-fourth of infective endocarditis cases and proves fatal for up to 38 percent of patients who develop it. In light of that high mortality rate, physicians try to address risk factors such as poor dental health before cardiac surgery. Removing diseased teeth at some point before surgery as a preventive measure is common, but research on whether that helps has been limited. Medical guidelines acknowledge a lack of conclusive evidence, the Mayo researchers noted.
The new study shows that the risk for patients who do have teeth removed before heart surgery "may be higher than we thought," says senior author Kendra Grim, M.D., a Mayo Clinic anesthesiologist.
"We are always concerned with improving safety, and pulling infected teeth before heart surgery seemed to be the safer intervention. But we became interested in studying this complex patient group, as many patients that come to the operating room for dental surgery just before heart surgery are quite ill," Dr. Grim says.
The study is believed to be the largest so far evaluating adverse outcomes after pre-cardiac surgery dental extractions. The researchers studied outcomes in 205 adult Mayo patients who had teeth pulled before cardiovascular surgery. The study covered January 1, 2003, through Feb. 28, 2013; 80 percent of the patients were men, the median age at the time of tooth extraction was 62, and the median time lapse between dental extraction and heart surgery was seven days. The research found:
Six patients, or 3 percent, died in the period between their tooth extraction and the planned cardiac procedure.
Another six died after heart surgery, all while still hospitalized.
Ten patients, or roughly 5 percent, had other major adverse outcomes after heart surgery, such as bleeding, stroke, kidney failure requiring dialysis, acute coronary syndrome or stroke-like transient ischemic attacks.
Due to unexpected complications or findings from dental surgery, at least 14 patients, or 7 percent, had to have heart surgery delayed.
More information is needed to understand why patients died or had other major adverse outcomes, the researchers say. In addition to the stress placed on the body by dental extraction and heart surgery themselves, potential factors include the severity of individual patients' heart disease, other serious health problems they may have had, and how they reacted to anesthesia.
The bottom line for patients and physicians, the researchers conclude: Rather than following a rule of thumb, physicians should evaluate each patient individually to weigh the possible benefit of tooth extraction before heart surgery against the risk of death and other major adverse events.
"We hope this study sparks future discussion and research," Dr. Grim says. "In the meantime, we recommend an individualized approach for these patients, to weigh their particular risk and benefit of a dental procedure before cardiac surgery with the information we have currently available."
Wednesday, February 26, 2014
Two bacteria prevalent in gum disease incite the growth of deadly Kaposi's sarcoma-related (KS) lesions and tumors in the mouth
Researchers from Case Western Reserve University have discovered how byproducts in the form of small fatty acids from two bacteria prevalent in gum disease incite the growth of deadly Kaposi's sarcoma-related (KS) lesions and tumors in the mouth.
The discovery could lead to early saliva testing for the bacteria, which, if found, could be treated and monitored for signs of cancer and before it develops into a malignancy, researchers say.
"These new findings provide one of the first looks at how the periodontal bacteria create a unique microenvironment in the oral cavity that contributes to the replication the Kaposi's sarcoma Herpesvirus (KSHV) and development of KS," said Fengchun Ye, the study's lead investigator from Case Western Reserve School of Dental Medicine's Department of Biological Sciences.
The discovery is described in The Journal of Virology article, "Short Chain Fatty Acids from Periodontal Pathogens Suppress HDACs, EZH2, and SUV39H1 to Promote Kaposi's Sarcoma-Associated Herpesvirus Replication."
The research focuses on how the bacteria, Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn), which are associated with gum disease, contribute to cancer formation.
Ye said high levels of these bacteria are found in the saliva of people with periodontal disease, and at lower levels in those with good oral health -- further evidence of the link between oral and overall physical health.
KS impacts a significant number of people with HIV, whose immune systems lack the ability to fight off the herpesvirus and other infections, he said.
"These individual are susceptible to the cancer," Ye said.
KS first appears as lesions on the surface of the mouth that, if not removed, can grow into malignant tumors. Survival rates are higher when detected and treated early in the lesion state than when a malignancy develops.
Also at risk are people with compromised immune systems: people on medications to suppress rejection of transplants, cancer patients on chemotherapies and the elderly population whose immune systems naturally weaken with age.
The researchers wanted to learn why most people never develop this form of cancer and what it is that protects them.
The researchers recruited 21 patients, dividing them into two groups. All participants were given standard gum-disease tests.
The first group of 11 participants had an average age of 50 and had severe chronic gum disease. The second group of 10 participants, whose average age was about 26, had healthy gums, practiced good oral health and showed no signs of bleeding or tooth loss from periodontal disease.
The researchers also studied a saliva sample from each. Part of the saliva sample was separated into its components using a spinning centrifuge. The remaining saliva was used for DNA testing to track and identify bacteria present, and at what levels.
The researchers were interested in Pg's and Fn's byproducts of lipopolysaccharide, fimbriae, proteinases and at least five different short-chain fatty acids (SCFA): butyric acid, isobutryic acid, isovaleric acid, propionic acid and acetic acid.
After initially testing the byproducts, the researchers suspected that the fatty acids were involved in replicating KSHV. The researchers cleansed the fatty acids and then introduced them to cells with quiescent KSHV virus in a petri dish for monitoring the virus' reaction.
After introducing SCFA, the virus began to replicate. But the researchers saw that, while the fatty acids allowed the virus to multiple, the process also set in motion a cascade of actions that also inhibited molecules in the body's immune system from stopping the growth of KSHV.
"The most important thing to come out of this study is that we believe periodontal disease is a risk factor for Kaposi sarcoma tumor in HIV patients," Ye said.
With that knowledge, Ye said those with HIV must be informed about the importance of good oral health and the possible consequences of overlooking that area.
Monday, February 3, 2014
The first evidence-based diagnostic criteria have been developed to help health professionals better diagnose temporomandibular disorders (TMD), commonly known as TMJ, a group of often-painful jaw conditions that affect an estimated 10 to 15 percent of Americans. The diagnostic criteria, developed by researchers in North America, Europe and Australia, are professional recommendations on how best to detect a disease or condition.
The new criteria, supported in part by the National Institutes of Health, comprise an improved screening tool to help researchers and health professionals including dentists more readily differentiate the most common forms of TMD and reach accurate diagnoses that are grounded in supportive scientific evidence. Historically, diagnostic criteria for TMD have been based on a consensus of expert opinion and often reflect a shared clinical perspective. None have been rigorously tested by scientists.
“We’ve had diagnostic criteria for years,” said Eric Schiffman, D.D.S., a co-lead author on the article, who studies TMD at the University of Minnesota School of Dentistry, Minneapolis. “What is unique here is instead of a panel of experts empirically deciding best practices, we relied on science as a methodology to test our best assumptions and see if we were actually correct.”
Called DC/TMD, the latest criteria are published today in the winter issue of the Journal of Oral and Facial Pain and Headache. They are available online at the International RDC/TMD Consortium Network website: http://www.rdc-tmdinternational.org/TMDAssessmentDiagnosis/DCTMD.aspx External Web Site Policy
Although TMD is commonly considered a jaw problem, researchers have determined that most people with chronic temporomandibular problems also contend with other ailments. In 1992, the Research Diagnostic Criteria for TMD (RDC/TMD) reflected this awareness. They were the first to integrate biological, psychological, and social factors into two distinct protocols, or axes. Axis I was designed to evaluate the physical diagnoses, while Axis II characterized the nature of a person's pain, distress, and disability. The criteria were translated into 18 languages and become the most widely used diagnostic system among TMD researchers.
But the RDC/TMD dual axes represented a first step with biopsychosocial diagnostic criteria. In the early 2000s, the NIH's National Institute of Dental and Craniofacial Research (NIDCR) assembled a group of experts to lead the first comprehensive assessment of the criteria. The group found Axis I in particular to be less valid than previously thought, leading to a mandate from the TMD clinical and research communities to create the diagnostic equivalent of RDC/TMD 2.0.
All agreed at the outset that the "R" was no longer needed. Research criteria, while useful for scientists in the laboratory and clinic, can leave researchers and health care providers using different diagnostic terms, measures, and tools.
“A common language allows clinicians to communicate more easily to researchers about their daily diagnostic challenges,” said Richard Ohrbach, D.D.S., Ph.D., a co-lead author on the publication who studies TMD at the University at Buffalo School of Dental Medicine in New York. “Conversely, a common language allows research findings to be more easily integrated into a clinical setting and improve patient care.”
The DC/TMD start with a refined version of Axis I, the physical assessment. It begins with an easily administered patient questionnaire that is specially designed to detect pain-related TMD. If TMD is detected, the protocol moves on to newly crafted diagnostic criteria to help practitioners differentiate among the common subtypes. In field tests, the diagnostic criteria for painful TMD were found to have at least 86 percent sensitivity and 97 percent specificity. Sensitivity refers to how well a test identifies a person with a given ailment, while specificity characterizes the ability to identify correctly those who are not affected.
Axis II, the psychosocial assessment, screens patients to assess pain location, pain intensity, pain-related disability, psychological distress, degree of jaw dysfunction, and presence of oral habits (i.e.,e.g. grinding teeth) that may contribute to the dysfunction. If more information is needed, a more comprehensive follow-up questionnaire is available to tap into additional anxiety measures and the possible presence of other pain-causing physical ailments. Both instruments have been scientifically validated.
“By diagnosing the person, beyond only the physical condition, a whole avenue of treatment options opens up,” said Schiffman. “Instead of prescribing mouth guards, exercises, or surgery, practitioners can consider trying bio-behavioral treatments including relaxation techniques and biofeedback to help the patient successfully manage their TMD. In short, you can better customize the treatment to fit the whole person, not just their disorder.”
The National Institute of Dental and Craniofacial Research (NIDCR) is the Nation’s leading funder of research on oral, dental, and craniofacial health. The NIDCR-supported International RDC/TMD Consortium Network provided the investigative framework for researchers from North America, Europe, and Australia to develop an improved diagnostic system and test its validity. Visit the NIDCR website at http://www.nidcr.nih.gov.