Temporomandibular disorders (TMDs), such as myofascial pain of the masticatory muscles and degenerative joint disease of the temporomandibular joint (TMJ), affect over 10 million Americans, have annual health care and societal costs estimated to be $750,000,000, and are recognized as a significant women's health problem. To date, it is unknown if there are gender based interactions between the variables of neuromuscular organization of the masticatory muscles and static mechanics that are significant in the pathogenesis of some TMDs. Our long-term goals are to improve the understanding of the role of mechanics in TMDs and explore the reason for its predilection in women. To achieve this goal, the proposed study will use validated computer-assisted numerical model predictions of muscle and TMJ forces in subjects with and without TMDs.
Specific Aim #1 will establish that the neuromuscular objective of minimization of joint loads is the basis of sagittal TMJ eminence shape in subjects with and without TMDs. Minimization of joint loads is a leading candidate objective since intracapsular stresses would be reduced, thereby reducing potential for fatigue failure of TMJ tissues.
Specific Aim #2 will demonstrate that the neuromuscular objectives for muscle force allocation during biting are not significantly different in individuals with and without TMDs. We hypothesize that the neuromuscular objectives of a) Minimization of joint loads, and/or b) Minimization of muscle effort, explain the apportionment of muscle forces during biting in humans.
Specific Aim #3 will demonstrate that for a given bite force, muscle and TMJ forces are larger in 1) subjects with TMDs compared to healthy subjects, and 2) women compared to men. We expect that numerical models, validated by comparing model predictions for a given subject with results measured from that subject, can be used to assess and compare variables that predispose higher muscle and TMJ forces. The impact of this project on health is the provision of clinical tools (validated numerical models) for TMDs that will: identify susceptible people, diagnose problematic structural relationships that could be corrected by surgery or other treatments, and provide essential information for future tissue engineering research.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
7R01DE016417-03
Application #
7343368
Study Section
Special Emphasis Panel (ZRG1-CFS (01))
Program Officer
Kusiak, John W
Project Start
2006-03-01
Project End
2009-02-28
Budget Start
2007-03-01
Budget End
2008-02-29
Support Year
3
Fiscal Year
2007
Total Cost
$479,075
Indirect Cost
Name
University of Missouri Kansas City
Department
Dentistry
Type
Schools of Dentistry
DUNS #
010989619
City
Kansas City
State
MO
Country
United States
Zip Code
64110
Gallo, L M; Fankhauser, N; Gonzalez, Y M et al. (2018) Jaw closing movement and sex differences in temporomandibular joint energy densities. J Oral Rehabil 45:97-103
Iwasaki, L R; Gonzalez, Y M; Liu, Y et al. (2017) Mechanobehavioral Scores in Women with and without TMJ Disc Displacement. J Dent Res 96:895-901
Iwasaki, L R; Gonzalez, Y M; Liu, Y et al. (2017) TMJ energy densities in healthy men and women. Osteoarthritis Cartilage 25:846-849
Khawaja, Shehryar N; Crow, Heidi; Mahmoud, Ruba F G et al. (2017) Is There an Association Between Temporomandibular Joint Effusion and Arthralgia? J Oral Maxillofac Surg 75:268-275
Wei, F; Van Horn, M H; Coombs, M C et al. (2017) A pilot study of nocturnal temporalis muscle activity in TMD diagnostic groups of women. J Oral Rehabil 44:517-525
Iwasaki, L R; Gonzalez, Y M; Liu, H et al. (2015) A pilot study of ambulatory masticatory muscle activities in temporomandibular joint disorders diagnostic groups. Orthod Craniofac Res 18 Suppl 1:146-55
Gallo, L M; Iwasaki, L R; Gonzalez, Y M et al. (2015) Diagnostic group differences in temporomandibular joint energy densities. Orthod Craniofac Res 18 Suppl 1:164-9
Khawaja, Shehryar N; Iwasaki, Laura R; Dunford, Robert et al. (2015) Association of Masseter Muscle Activities during Awake and Sleep Periods with Self-Reported Anxiety, Depression, and Somatic Symptoms. J Dent Health Oral Disord Ther 2:
Khawaja, S N; McCall Jr, W; Dunford, R et al. (2015) Infield masticatory muscle activity in subjects with pain-related temporomandibular disorders diagnoses. Orthod Craniofac Res 18 Suppl 1:137-45
Khawaja, S N; Nickel, J C; Iwasaki, L R et al. (2015) Association between waking-state oral parafunctional behaviours and bio-psychosocial characteristics. J Oral Rehabil 42:651-6

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