Improving Oral health is a priority of the NHMRC Strategic Plan 2003-06. The proposed research is consistent with this priority as we will achieve a better understanding of the cortical control of human jaw muscles, which serves as the foundation for understanding conditions in which their function is impaired, and the development of rational therapies for these conditions. Transcranial magnetic stimulation will be used to activate the motor cortex and corticobulbar descending pathway to the jaw ....Improving Oral health is a priority of the NHMRC Strategic Plan 2003-06. The proposed research is consistent with this priority as we will achieve a better understanding of the cortical control of human jaw muscles, which serves as the foundation for understanding conditions in which their function is impaired, and the development of rational therapies for these conditions. Transcranial magnetic stimulation will be used to activate the motor cortex and corticobulbar descending pathway to the jaw muscles. The AIM 1 study will provide important new information about the functional organisation of the motor cortex in the control of jaw muscles during speech. This information is needed to improve understanding of dysarthria, a common disturbance of speech due to impaired muscular control following unilateral cortical stroke, and less common conditions involving speech motor control such as spasmodic dysphonia (a cranial dystonia) and dysprosody (disturbance of speech articulation and rhythm found in Parkinson s disease). The AIM 2 and 3 studies will provide a comprehensive characterization of cortical inhibitory mechanisms that are an important but poorly understood component of the cortical control of jaw muscles. This information is necessary to understand normal function, and the mechanisms of disturbances to jaw muscle function with neurological disease or injury. The AIM 4 studies will show whether impaired cortical inhibition contributes to the pathophysiology of two poorly understood disorders affecting jaw muscles (bruxism and oromandibular dystonia). Current therapies for these conditions are unsatisfactory, due to a limited understanding of the mechanisms involved. If cortical inhibition is abnormal in these conditions this will lead to novel treatment therapies (e.g., drugs to correct the imbalance, or strategies to induce plastic change in the cortex).Read moreRead less
Control Of Mastication By Periodontal Mechanoreceptors In Man
Funder
National Health and Medical Research Council
Funding Amount
$169,990.00
Summary
Despite the importance in chewing and speech, very little is known regarding the fine control of jaw muscles. A thorough understanding of the control of the jaw muscles is at the base of improved diagnosis and treatment of many chewing disorders. For example: We still do not understand the causes of the jaw muscle-joint pain disorder (temporomandibular dysfunction) which accounts for about 5 % of total dental patients. The current treatments, including pain killers, night plates and massage cure ....Despite the importance in chewing and speech, very little is known regarding the fine control of jaw muscles. A thorough understanding of the control of the jaw muscles is at the base of improved diagnosis and treatment of many chewing disorders. For example: We still do not understand the causes of the jaw muscle-joint pain disorder (temporomandibular dysfunction) which accounts for about 5 % of total dental patients. The current treatments, including pain killers, night plates and massage cure only about half of all patients. Improved diagnosis and treatment techniques require more precise elaboration of the neural and muscular mechanisms of chewing. Why do the chewing forces in toothless individuals, despite well fitting dentures, fall to about 20 % of the value in teethed individuals? Do jaw muscles in these subjects weaken because they get less feedback from the receptors around the teeth? How does the chewing force automatically adjust to overcome sudden or gradual changes in the characteristics of foodstuff? Although bite to bite changes in the chewing force is observed in subjects with natural teeth, no such changes occur in toothless subjects or subjects chewing with implanted bridges. How do the receptors adjust the activation of jaw muscles so that bite force is applied in the right direction and right amount at each bite? The aim of this study is to define the importance of the periodontal mechanoreceptors (tiny nerve cells that are situated between the roots of the teeth and the jaw bone that signal bite force to the brain) in the control of jaw muscles. This study will, therefore, illustrate the importance of keeping the teeth and gums healthy for the development of strong, smooth and well-controlled chewing forces, and potentially create opportunities to improve chewing (and thereby quality of life) in toothless individuals or those experiencing other difficulties in chewing.Read moreRead less
Temporomandibular Disorders (TMD) are characterised by pain and limited jaw movement and are a significant issue. Current management is influenced by the view of a simple association between pain and limited movement. This study will test a new theory that an individual's motor response to pain is influenced by the complexity of the jaw motor system as well as the individual's pain experience. This project will point towards individualised recommendations for effective management of TMD.
An FMRI Analysis Of The Functional Organization Within The Brain Of Experimental Superficial And Deep Orofacial Pain
Funder
National Health and Medical Research Council
Funding Amount
$307,526.00
Summary
This project will investigate how the human brain processes a number of important aspects of human jaw muscle pain that are clinically relevant but poorly understood. For example, we do not understand why jaw muscle pain has such different behavioural effects to skin pain. Jaw muscle pain is associated with a significant emotional component not seen in with skin pains. Also, skin pain usually has a sharp or burning quality, is well-localized and is readily treated, while jaw muscle pain is a dee ....This project will investigate how the human brain processes a number of important aspects of human jaw muscle pain that are clinically relevant but poorly understood. For example, we do not understand why jaw muscle pain has such different behavioural effects to skin pain. Jaw muscle pain is associated with a significant emotional component not seen in with skin pains. Also, skin pain usually has a sharp or burning quality, is well-localized and is readily treated, while jaw muscle pain is a deep pain that has a dull, aching quality that may be referred to related sites of the face, head and neck. It is also not known why jaw muscle pain is more common in females in comparison to males. Chronic jaw muscle pain is a major symptom of patients with Temporomandibular Disorders, the most common form of non-dental orofacial pain and that involves pain in or about the jaw joint and-or jaw muscles, and often limitation of jaw movement. Chronic jaw muscle pain can have a severe effect on quality of life but its diagnosis and management is difficult. Despite the widespread prevalence of chronic orofacial pains, we have little information on the central processing of chronic human orofacial pain. This proposal will improve our fundamental understanding of how jaw muscle pain is processed in the brain. The way that the central nervous system processes and represents jaw muscle pain will help explain why these pains present differently in the clinic and should provide important information on the differences between females and males in the representation of jaw muscle pain. This information on the central processing of chronic orofacial pain is crucial to inform the direction of novel or specific management strategies. Our long-term goal is to improve the diagnosis and management of patients with Temporomandibular Disorders, and the present application represents a major new direction of research.Read moreRead less
Effects Of Jaw Muscle Pain On Jaw Muscle Activity And Jaw Movement In Humans
Funder
National Health and Medical Research Council
Funding Amount
$337,770.00
Summary
Chronic facial muscle pain is a significant community health problem that is poorly understood. Current treatments are based on the idea that structural or stress-related factors result in increased jaw muscle activity which then generates pain that in turn leads to more muscle activity - the so-called Vicious Cycle Theory. Treatments therefore aim to break the cycle by focussing on reducing muscle activity and thereby alleviate the pain. There is currently, however, little scientific evidence f ....Chronic facial muscle pain is a significant community health problem that is poorly understood. Current treatments are based on the idea that structural or stress-related factors result in increased jaw muscle activity which then generates pain that in turn leads to more muscle activity - the so-called Vicious Cycle Theory. Treatments therefore aim to break the cycle by focussing on reducing muscle activity and thereby alleviate the pain. There is currently, however, little scientific evidence for this Theory. Another theory has been recently proposed in the Pain Adaptation Model. This model says that changes in muscle activity and movement are protective against further pain rather than the cause of the pain. The evidence, however, for this model is limited and conflicting. The current lack of understanding of facial muscle pain limits advancement in its management. Our long-term goal is to improve the management of patients with facial pain. The present application aims to determine whether muscle pain alters jaw muscle activity and jaw movement. Our preliminary clinical data provide compelling evidence for the Pain Adaptation Model. We are confident of a better understanding of what goes wrong in the jaw muscles in chronic facial pain and this will have implications for muscle pains elsewhere in the body. The outcome may help to refute the Vicious Cycle Theory, and help shift the focus away from signs and symptoms associated with the jaw muscles, and re-direct the focus to the alleviation of pain as the primary management goal. The information obtained should also provide a solid basis on which treatments can be tested for optimal resolution of symptoms, and an evidence-based approach in the management of facial pain.Read moreRead less
Reflex Control Of Human Jaw Muscles By Periodontal Mechanoreceptors
Funder
National Health and Medical Research Council
Funding Amount
$405,173.00
Summary
An understanding of the functional connection between the jaw muscles and various receptor organs in and around the mouth is necessary to elucidate the process of chewing and its underlying rules. Unless the details of this functional connection in health and disease are thoroughly understood, the diagnosis and treatment of chewing related disorders will remain at the present state. For example: a We still do not know why chewing in edentulous subjects is less efficient and why the bite forces i ....An understanding of the functional connection between the jaw muscles and various receptor organs in and around the mouth is necessary to elucidate the process of chewing and its underlying rules. Unless the details of this functional connection in health and disease are thoroughly understood, the diagnosis and treatment of chewing related disorders will remain at the present state. For example: a We still do not know why chewing in edentulous subjects is less efficient and why the bite forces in these individuals immediately fall to about 20 % of the teethed value. Do jaw muscles in these subjects get weak because they get less support from the receptor organs around the teeth? a We still do not understand the cause-causes of the temporomandibular dysfunction (a painful disease involving jaw muscles) which forms 18.7 % of total dental patients consulted per week in South Australia. This South Australian study indicated that the current treatments (such as pain killers, night plates, massage) Ocures? only about the half of all patients. We cannot increase the success of the treatment if we do not fully understand the control mechanisms of chewing? It is expected that the results of this study will establish the functional connection between one of the most important receptor organs in the mouth (periodontal mechanoreceptors) to the jaw muscle motoneurons in subjects with healthy teeth and gums and will illustrate the importance of keeping the periodontium healthy for developing strong and smooth masticatory forces. This knowledge can also allow us to treat jaw related disorders by approaches that bring back normal operation of the system. For example, this knowledge may help us design active dentures that replace the missing support.Read moreRead less
Exertional Dyspnoea With Increased Filling Pressure - Mechanisms And Treatment Strategies
Funder
National Health and Medical Research Council
Funding Amount
$387,793.00
Summary
Patients with early heart disease often present with shortness of breath with exercise, as myocardial reserve at that stage is usually sufficient to maintain normal function at rest . Indeed, much myocardial dysfunction may originate from the modern lifestyle, including inactivity, obesity, the metabolic syndrome and type II diabetes. The potential benefits of making a definitive early diagnosis are large, because it seems more likely that an impact can be made on the disease process (and theref ....Patients with early heart disease often present with shortness of breath with exercise, as myocardial reserve at that stage is usually sufficient to maintain normal function at rest . Indeed, much myocardial dysfunction may originate from the modern lifestyle, including inactivity, obesity, the metabolic syndrome and type II diabetes. The potential benefits of making a definitive early diagnosis are large, because it seems more likely that an impact can be made on the disease process (and therefore, outcome) than with late stage disease. Current treatment strategies are expensive and because they are directed at end-organ damage (heart failure, heart attacks etc), rather ineffective. This multispecialty, multidisciplinary group will undertake a series of unique studies aimed at identifying early cardiovascular disease. The strategy will involve detection of abnormal filling behaviour at stress echocardiography, with randomization into longterm and short-term trials to examine various therapeutic strategies. Sensitive new cardiovascular imaging techniques will be used to detect preclinical abnormalities in the structure and function of the heart and vasculature, facilitating a mechanistic understanding of the process of increasing filling pressure with exercise.Read moreRead less
A Program Of Research Addressing The Transition From Health To Advanced Cardiovascular Disease.
Funder
National Health and Medical Research Council
Funding Amount
$13,017,057.00
Summary
Cardiovascular disease (CVD) is the major cause of death and disability in Australia and worldwide. This burden will increase without new knowledge. We will address knowledge gaps that delay more effective prevention and control. Our team has a strong track record of influencing clinical practice of CVD prevention, treatment and technology transfer. For many, the first indication of a heart problem is sudden heart attack or death. By understanding mechanisms we aim to develop new tests and treat ....Cardiovascular disease (CVD) is the major cause of death and disability in Australia and worldwide. This burden will increase without new knowledge. We will address knowledge gaps that delay more effective prevention and control. Our team has a strong track record of influencing clinical practice of CVD prevention, treatment and technology transfer. For many, the first indication of a heart problem is sudden heart attack or death. By understanding mechanisms we aim to develop new tests and treatments that prevent heart attack, heart failure and other serious consequences of atherosclerosis.Read moreRead less