title: Dynamic shear behavior of mandibular condylar cartilage is dependent on testing direction.
abstract: Little information is available on the direction-dependency of shear behavior in mandibular condylar cartilage. Therefore, we tested the hypothesis that such a dependency of the dynamic shear properties is present in mandibular condylar cartilage. From each of 17 condyles, two cartilage-bone plugs were dissected and tested in a simple shear sandwich configuration under a compressive strain of 10%. Sinusoidal shear strain (frequency range: 0.01-10 Hz) was applied in the medio-lateral or antero-posterior direction with an amplitude of 1.0%, 2.0%, and 3.0%. The magnitudes of the dynamic shear moduli, as calculated from the resulting shear stress, were found to increase with applied frequency and the shear strain amplitude. The values |G*|, G' and G'' for a medio-laterally applied shear were about 20-33% of those in the antero-posterior shear, although the loss tangent (elasticity/viscosity ratio) was almost the same. In conclusion, the present results clearly show the direction-dependent characteristic of the mandibular condylar cartilage in dynamic shear.
authors.affiliation: Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University, Graduate School of Biomedical Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 7348553, Japan. etanaka@hiroshima-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Iwabuchi
authors.forename: Emanuel B
authors.initials: EB
authors.lastname: Rego
authors.forename: Jan Harm
authors.initials: JH
authors.lastname: Koolstra
authors.forename: Eizo
authors.initials: E
authors.lastname: Yamano
authors.forename: Takuro
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Aki
authors.initials: A
authors.lastname: Kawazoe
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Kawai
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tanne
mesh_terms: D000818:Animals; D002356:Cartilage / Q000502:physiology*; D004548:Elasticity; D008335:Mandibular Condyle / Q000502:physiology*; D033081:Shear Strength; D034421:Sus scrofa; D013718:Tensile Strength / Q000502:physiology; D014783:Viscosity