Premium
Diagnostic group differences in temporomandibular joint energy densities
Author(s) -
Gallo L. M.,
Iwasaki L. R.,
Gonzalez Y. M.,
Liu H.,
Marx D. B.,
Nickel J. C.
Publication year - 2015
Publication title -
orthodontics and craniofacial research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 55
eISSN - 1601-6343
pISSN - 1601-6335
DOI - 10.1111/ocr.12074
Subject(s) - temporomandibular joint , medicine , population , orthodontics , nuclear medicine , environmental health
Structured Abstract Objectives Cartilage fatigue, due to mechanical work, may account for precocious development of degenerative joint disease in the temporomandibular joint ( TMJ ). This study compared energy densities (mJ/mm³) in TMJ s of three diagnostic groups. Setting and Sample Population Sixty‐eight subjects (44 women, 24 men) gave informed consent. Diagnostic criteria for temporomandibular disorders ( DC / TMD ) and imaging were used to group subjects according to presence of jaw muscle or joint pain (+ P ) and bilateral disk displacement (+ DD ). Material and Methods Subjects (+ P + DD , n = 16; – P + DD , n = 16; and – P – DD , n = 36) provided cone‐beam computed tomography and magnetic resonance images, and jaw‐tracking data. Numerical modeling was used to determine TMJ loads ( F normal ). Dynamic stereometry was used to characterize individual‐specific data of stress‐field dynamics during 10 symmetrical jaw‐closing cycles. These data were used to estimate tractional forces ( F traction ). Energy densities were then calculated as W / Q ( W = work done or mechanical energy input=tractional force × distance of stress‐field translation, Q = volume of cartilage). anova and T ukey– K ramer post hoc analyses tested for intergroup differences. Results Mean ± standard error energy density for the +P+ DD group was 12.7 ± 1.5 mJ/mm³ and significantly greater (all adjusted p < 0.04) when compared to – P + DD (7.4 ± 1.4 mJ/mm³) and –P– DD (5.8 ± 0.9 mJ/mm³) groups. Energy densities in –P+ DD and –P– DD groups were not significantly different. Conclusion Diagnostic group differences in energy densities suggest that mechanical work may be a unique mechanism, which contributes to cartilage fatigue in subjects with pain and disk displacement.