Project 434805

Pain is the primary cause of long-term disability, and it poses the most significant health-related burden on Canadian society. Temporomandibular disorders (TMD), a set of conditions affecting the jaw muscles and the temporomandibular joint (the jaw joint), are the most common cause of chronic (persistent) pain relating to the mouth and face. The causes of muscular TMD, the most common TMD, are still poorly understood, and a definite cause of this condition has yet to be identified. This uncertainty contributes to misdiagnosis, delays accurate diagnoses, and leads to inappropriate treatments. For these reasons, more than 30% of patients with TMD have recurrent or persistent pain after 5 years regardless of the treatment they had received. Currently, patients' self-reported pain is the main way that TMD severity is diagnosed, but the experience of pain is influenced by other factors, including cultural context and coping strategies, so this may not be the most accurate way to determine a case of TMD's severity. Therefore, in order to improve diagnosis and treatment of TMD, this project aims to identify and characterize the muscular and neural abnormalities associated with chronic muscular TMD. This will allow us to determine whether biological severity - in other words, the extent of changes in the jaw muscles and neurological systems of people with TMD - predicts the extent of the disability caused by a given patient's TMD. To accomplish this, we will use multiple methods to characterize the structure and function of the jaw muscles in patients with chronic TMD, as well as the structure of their nerves and brains. In the long term, our project will allow us to classify the extent and spread of TMD, leading to increased understanding of biological severity, improved diagnosis, more efficient and specific treatments, and a reduced burden on patients and the healthcare system.