The researchers at the Oregon Health & Science University’s School of Dentistry have discovered a novel function of the peptide known as nerve growth factor (NGF) in the development of the trigeminal nerve. The trigeminal nerve provides the signaling pathway for periodontal pain, dental surgical pain, and pain associated with temporomandibular disorder, trigeminal neuralgia, migraine and other neuropathic and inflammatory conditions. The study is posted online in Neuropeptides and will appear in print issues of that journal in early 2009. Working with researchers in the dental school departments of Endodontology and Integrative Biosciences, second-year Endodontology resident and lead author of the study, Leila Tarsa, DDS, MS, found a new mechanism involved in establishing junctions known as synapses between trigeminal nerve cells. Nerve cells communicate with one another through chemicals called transmitters that are released at synapses. The transmitter release from nerve cells endings is possible only if aided by several molecules that are critical for proper function of the synapse. Dr. Tarsa’s research shows that NGF promotes transport of one of the molecules (called synaptophysin) from the nerve cell body to its ending. “This study has broad implications for trigeminal nerve regeneration,” said Agnieszka Balkowiec, MD, PhD, assistant professor of integrative biosciences and adjunct assistant professor of physiology and pharmacology, senior author of this study and whose lab hosted the research. The study was supported by grants from the NIH and the Medical Research Foundation of Oregon. (Source: OHSU, news@ohsu.edu, January 7, 2009)

New York University (NYU) researchers published a study in the Journal of Periodontology on the treatment outcomes of dental flossing in twins. The purpose was to assess the effects of dental flossing on the microbial composition of interproximal plaque samples in matched twins. It was a 2-treatment, examiner masked, randomized, parallel-group, controlled study. Researchers studied 51 well-matched twin pairs (each set was a case and a control), regarding their treatment responses to dental flossing over a 2-week period. After 2 weeks, putative periodontal pathogens and cariogenic bacteria were overabundant in the group that did not floss compared to the group that performed flossing. The twins who flossed had a significant decrease in gingival bleeding compared to twins who did not floss. Relative to baseline, bleeding scores were reduced by 38% over the 2 weeks in the flossing group of twins. The author concluded, “In a well-matched twin cohort, tooth and tongue brushing plus flossing significantly decreased the abundance of microbial species associated with periodontal disease and dental caries after 2-week program.” Because they live together and have similar dietary habits and health practices, twins are considered excellent subjects for research that compares periodontal diseases and dental caries development in people of the same age from similar environments. This research stems from a 5-year study funded by a National Institute of Dental and Craniofacial Research grant to assess the relative significance of potential factors in caries development utilizing 500 pairs of twins. (Source: NYU College of Dentistry, December 17, 2008)

Your heart rate changes from minute to minute, depending on such factors as whether you are standing up or lying down, moving around or sitting still, stressed or relaxed. When you have been at rest for a while the heartbeat settles down and this is your heart rate. Slowing the heartbeat with exercise and stress reduction may help you enjoy more beats, reports the Harvard Heart Letter. Sixty years ago, researchers showed that men with fast resting heart rates were more likely to develop high blood pressure than those with slower rates. Since then, a high resting heart rate has been linked to atherosclerosis, sudden death, and an increased risk of dying from cardiovascular disease. Why? Each pulse of blood puts a mild stress on artery walls. More beats per minutes means more stress. A faster heartbeat also gives the coronary arteries less time to fill with blood. This can lead to an imbalance between heart cell’s demand for oxygen and the heart ability to provide it. Resting heart rate seems to be a common denominator for various types of heart diseases. A tantalizing possibility is that lowering your heart rate could help protect you from heart disease and may even let your heart beat for a longer period of time. The Harvard Heart Letter notes that if your resting heart rate is high, you can do something about it: exercise more and reduce stress. When you exercise, your heart beats faster during the activity and for a short time afterward. But exercising every day gradually slows the resting rate. The relaxation response, meditation, and other stress-busting techniques also lower heart rate over time. (Source: Harvard Heart Letter, December 2008, Harvard Health Publications)