Getting at the cause of severe jawbone pain
Dental research is under way at the JGH to gain a better understanding of temporo-mandibular disorders (TMD), encompassing several problems associated with pain in and around the joint on either side of the jaw bone. TMD is second only to back disorders as a source of chronic pain.
This involvement by the hospital highlights the strong and growing connection between dental research and general health, as well as the JGH’s increasing participation in dental research.
Among the leaders is Dr. Ana M. Velly, an investigator at the Lady Davis Institute (LDI), who is heading research into the cause and risk factors that underlie the persistence of TMD. Dr. Velly is an Associate Professor in McGill’s Faculty of Dentistry and an Associate Member in the Centre for Clinical Epidemiology and Community Studies at the LDI.
TMD is a particularly troubling condition, says Dr. Mervyn Gornitsky, who is Research Director and Emeritus Chief in the JGH Department of Dentistry, and has served for more than 60 years at the hospital.
“It has a physical manifestation, in that the muscles in the jaw spasm. But there is also a psychological element, in that it can be brought on by stress.”
Two current projects focus on this problem. One seeks to assess the causes, evaluate underlying risk factors, and detect salivary biomarkers observable in TMD patients. The other looks at risk factors associated with patients’ adherence to treatment.
Funding for dental research
Research projects in the JGH Department of Dentistry currently receive over $500,000 in funding from the Canadian Institutes for Health Research, the National Institutes of Health in the United States, Parkinson Canada, MITACS Canada, the Senator Leo Kolber Fund for Parkinson Biomarker Research, and the Dr. Mireille and Murray Steinberg Foundation.
“Our objective is to understand the mechanisms that contribute to the transition from acute to chronic pain,” Dr. Velly explains, referring to the broad range of her research into pain.
“This is a significant problem that affects patients with all types of conditions. For example, we are studying breast cancer patients to ascertain whether their initial health condition, psychological factors, cancer characteristics and salivary biomarkers offer clues to whether patients will experience acute and chronic post-surgical pain.
“Pain is peculiar—at once a physical response, but also incorporating psychological and genetic factors. Some people feel it more than others.”
Two of Dr. Velly’s projects involve assessing the risk factors between opioids and cancer: one looks at cancer incidence, and the other at cancer recurrence, with both having received CIHR operating grants. In addition, a third CIHR-funded randomized clinical trial study will examine pain management after arthroscopic shoulder surgery.
Using saliva to help solve medical mysteries
As home to the largest salivary biobank in Canada, the JGH has played a key role in a major multi-site study on oral manifestations of scleroderma and their effect on the quality of life.
This involvement by the JGH highlights the growing importance of using saliva to analyze biomarkers in detecting disease or infection, as well as the strong connection between dental research and general health.
The recently completed study was funded by the Canadian Institutes of Health Research (CIHR), with participation by Dr. Murray Baron, JGH Chief of Rheumatology. It examined aspects of scleroderma, an autoimmune disease that is characterized by hardening of connective tissues and can lead to substantial damage to the skin, blood vessels, muscles and internal organs.
The study made use of the JGH’s salivary biobank, which contains samples from more than 2,500 patients of all ages of varying health status and comorbidities. The biobank is co-directed by Dr. Gornitsky and by Dr. Hyman Schipper, a neurologist and senior investigator in the LDI.
Saliva samples can be of great help in detecting biomarkers, which are bits of biological data that reveal the presence of conditions as varied as cancer, Alzheimer’s disease, Parkinson’s disease, diabetes, chronic pain and scleroderma.
“Saliva can serve as an excellent repository for biomarkers, because it is easier to collect than blood or urine, and it can be obtained as frequently as necessary,” explains Dr. Gornitsky. “It’s as simple as having a patient spit in a cup.”
Dr. Melvin Schwartz, Chief of Dentistry, notes that the JGH is one of the few hospitals in Canada where a department of dentistry maintains its own active clinical research program.
“Our own mission coincides with the overall mission of the hospital,” he says, “which is to provide excellent patient care, to teach aspiring practitioners, and to advance scholarly activity.”
In addition to maintaining the salivary biobank, Dr. Schipper examines saliva samples for biomarkers of oxidative stress, which can be indicative of Parkinson’s disease and Alzheimer’s disease.
“We have observed changes in a certain protein and enzyme in the saliva of patients with neurodegenerative disease,” he says. “Evidence suggests that we may be successful in using saliva to diagnose very early onset. This will enable us to tailor care to suit our patients’ needs, possibly delay progression of the disease, and contribute to a higher quality of life for a longer period of time.”
For more than 10 years, Dr. Schipper has had a fruitful collaboration with Dr. Gornitsky. Together they have produced nine major papers, supervised eight students, and won three Hinman Prizes for Best Poster Presentation at McGill University’s Department of Dentistry Research Day. They have also founded HemOX Biotechnologies to further develop and commercialize the salivary HO1 biomarker as a diagnostic tool.