Speech and chewing are accomplished automatically by the jaw muscles which have both the power to chew meat and even bone, and the precision to make extremely fine adjustments to the shape of the mouth that enable speech. The brain needs constant inputs from sensory receptors in and around the mouth to control these muscles. We will investigate how these sensory mechanisms automatically fine-tune the activity of the jaw muscles and the mechanisms that keep the jaw in its normal position when the ....Speech and chewing are accomplished automatically by the jaw muscles which have both the power to chew meat and even bone, and the precision to make extremely fine adjustments to the shape of the mouth that enable speech. The brain needs constant inputs from sensory receptors in and around the mouth to control these muscles. We will investigate how these sensory mechanisms automatically fine-tune the activity of the jaw muscles and the mechanisms that keep the jaw in its normal position when the subject is sitting quietly, or when the head is moving up and down during running. This normal rest position of the jaw is a vital point of reference for dentists who are making false teeth and for surgeons who are restoring damaged faces, but it is not known what mechanisms are responsible for it. Anyone who has experienced a sore tooth or sore jaw muscles will know that pain adversely affects normal chewing. A common symptom is limitation of jaw movements. We will determine how pain affects the control of jaw muscles. This is important for people with chronic facial pain from arthritis of the jaw joint or from grinding their teeth while they are asleep. Even if it is not possible to eliminate their pain, we hope to suggest approaches which will alleviate its effects. Another part of our study involves a computer model of the chewing system. Computer models enable scientists to examine the effect of various interventions such as surgery or orthodontics on a model before these are tried on humans. It is also possible to use such a virtual patient to answer important functional questions that cannot be examined in humans because the methods are unavailable, or because the procedures would be ethically unacceptable. The current version of the computer model is quite sophisticated anatomically, but lacks important information on the control systems that activate the muscles. We will collaborate with the developers of the model by providing this information.Read moreRead less
The South Australian Dental Longitudinal Study has been the first comprehensive dental longitudinal study of older adults to be conducted in Australia. Participants were aged 60+ years at the 1991 baseline data collection, and were a random sample of community-dwelling older adults in urban Adelaide and rural Mount Gambier. The 11-year follow-up data collection will build upon the previous study findings to provide important and new information about the onset and progression of oral diseases in ....The South Australian Dental Longitudinal Study has been the first comprehensive dental longitudinal study of older adults to be conducted in Australia. Participants were aged 60+ years at the 1991 baseline data collection, and were a random sample of community-dwelling older adults in urban Adelaide and rural Mount Gambier. The 11-year follow-up data collection will build upon the previous study findings to provide important and new information about the onset and progression of oral diseases in older Australians. It will also assist with the identification of general health and other characteristics (socio-demographic, medical, functional, cognitive, nutritional, swallowing, dental history, oral hygiene care, financial, social support and oral disorder social impact characteristics) that are associated with oral diseases in various groups of older adults. Groups of older adults within the study include those who are healthy and living in the community, those who are frail and use support services, and those who have moved into residential care. This information will assist both private and public health sectors, dental professionals and other health professionals with the identification of those older adults who are at high risk for developing oral diseases, such as those with dementia, those with physical disabilities, and those living in residential care. This 11-year data collection will be one of only 4 similar international studies currently being conducted, and will provide important comparison data for future studies of older Australians.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