[Effects of stress level on the biomechanical behavior of the temporomandibular joint disc in domestic pigs].
This study aimed to examine the responses of the temporomandibular joint (TMJ) disc against compression, to clarify the property of viscoelasticity and permeability of the disc, and to provide experimental data for further analyzing the mechanism of stress dissipation within the TMJ disc. With the use of confined compression mechanics and biphasic theory, creep experiments on eight TMJ discs of four domestic pigs were performed under three stress levels(0.07 MPa, 0.13 MPa and 0.30 MPa). The results showed that at 0.07 stress level, the compressive stiffness at 2 seconds of the anterior band(AB), intermediate zone(IZ) and posterior band(PB) of the disc was 4.48 MPa, 3.93 MPa and 6.31 MPa, respectively; the coefficient K of permeability was 0.272 x 10(-12) m4/NS, 0.30 x 10(-12) m4/NS, and 0.042 x 10(-12) m4/NS. At 0.30 Mpa level, the compressive stiffness increased to 14.07 MPa, 13.68 Mpa and 14.00 MPa; the coefficient K lowered to 0.017 x 10(-12) m4/NS, 0.012 x 10(-12) m4/NS and 0.005 x 10(-12) m4/NS. In conclusion, the TMJ disc has viscoelastic and biobiphasic properties against compression. The stiffness of the disc increases with the increment of stress level but the coefficient of permeability decreases. These findings demonstrate that the modulation of stress and of permeability may be two important factors influencing stress dissipation and shock absorption behavior of the disc during compressive and impact loads.
Bao
G
G
Department of Stomatology, Lanzhou Medical College, Lanzhou 73000.
Kang
H
H
Dong
Y
Y
Zhu
R
R
Chao
Y
Y
Yi
X
X
Chen
M
M
D000818:Animals; D000829:Animals, Domestic; D001696:Biomechanical Phenomena; D004548:Elasticity; D005260:Female; D008297:Male; D010539:Permeability; D013552:Swine; D019224:Temporomandibular Joint Disc / Q000502:physiology*; D013718:Tensile Strength