Viscoelastic properties of bovine retrodiscal tissue under tensile stress-relaxation.
To test the hypothesis that the condylar part of the retrodiscal tissue of the temporomandibular joint exhibits resistance to tensile force, we investigated its viscoelastic properties and stress-relaxation behavior under tension. Ten specimens were tested. Stress-relaxation tests were conducted from four different initial stress levels. The tissue exhibited a non-linear stress-strain relationship, which could be represented by a bilinear relation of two line segments. The stress-relaxation curves showed a marked drop in load during the initial 10 s and after 2 min the stress reached an almost steady non-zero level. This feature can be well represented by Kelvin's model. It is concluded that the condylar part of the retrodiscal tissue (a) exhibits a non-linear strain-dependent viscoelastic behavior (b), has a great capacity for energy dissipation and resistance to tensile forces, and (c) contributes to maintain the position of the disc relative to the condyle during jaw closing.
Tanaka
Eiji
E
Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan. etanaka@hiroshima-u.ac.jp
Hanaoka
Koichi
K
Tanaka
Masao
M
Van Eijden
Theo
T
Iwabe
Tatsunori
T
Ishino
Yoshihiro
Y
Sasaki
Akiko
A
Tanne
Kazuo
K
D000818:Animals; D002417:Cattle; D003799:Dental Stress Analysis; D004548:Elasticity; D066298:In Vitro Techniques; D008335:Mandibular Condyle / Q000502:physiology*; D008422:Materials Testing; D013314:Stress, Mechanical; D019224:Temporomandibular Joint Disc / Q000502:physiology*; D013718:Tensile Strength; D014783:Viscosity