title: Stress relaxation behaviors of articular cartilages in porcine temporomandibular joint.
abstract: In this study, we tested the compressive stress relaxation behaviors of the mandibular condylar and temporal cartilages in the porcine temporomandibular joint (TMJ). The aim was to determine the quantitative and qualitative similarities and differences of compressive stress relaxation behaviors between the two cartilages. Ten porcine TMJs were used; the articular surface was divided into 5 regions: anterior, central, posterior, lateral and medial. Compressive relaxation test was carried out at a strain level of 5% in each region of the two cartilages. The stress relaxation was monitored over a period of 5min. In all the regions of the two cartilages, the time-dependent stress relaxation curves showed a marked drop in stress within the initial 10s, which can be fitted by a standard linear viscoelastic model. The instantaneous moduli in the temporal cartilage were dominantly larger than those in the condylar cartilage, while the condylar cartilage had slightly larger relaxation moduli than the temporal cartilage except for the medial region. The both cartilages showed the regional differences in the compressive stress relaxation behavior, and in the temporal cartilage the lateral and medial regions revealed the largest values for the instantaneous and relaxation moduli. The present results demonstrate that the viscoelastic properties of compressive stress relaxation in both cartilages are region-specific, which might have an important implication for stress distribution and transmission along with the TMJ disc.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan. Electronic address: etanaka@tokushima-u.ac.jp.
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.affiliation: Department of Construction and Manufacturing Engineering, Faculty of Engineering, University of Oviedo, Gijón, Spain.
authors.forename: Fernández
authors.initials: F
authors.lastname: Pelayo
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan.
authors.forename: Namhee
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Construction and Manufacturing Engineering, Faculty of Engineering, University of Oviedo, Gijón, Spain.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Lamela
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Kawai
authors.affiliation: Department of Construction and Manufacturing Engineering, Faculty of Engineering, University of Oviedo, Gijón, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fernández-Canteli
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000502:physiology*; D004548:Elasticity; D008335:Mandibular Condyle / Q000502:physiology; D013314:Stress, Mechanical; D013552:Swine; D013704:Temporomandibular Joint / Q000502:physiology*; D014783:Viscosity
keywords: Articular cartilage; Stress relaxation; Temporomandibular joint; Viscoelasticity