TY - JOUR
T1 - Static and dynamic mechanics of the temporomandibular joint
T2 - Plowing forces, joint load and tissue stress
AU - Nickel, J.
AU - Spilker, R.
AU - Iwasaki, L.
AU - Gonzalez, Y.
AU - McCall, W. D.
AU - Ohrbach, R.
AU - Beatty, M. W.
AU - Marx, D.
PY - 2009/8
Y1 - 2009/8
N2 - Objectives - To determine the combined effects 1) of stress-field aspect ratio and velocity and compressive strain and 2) joint load, on temporomandibular joint (TMJ) disc mechanics. Setting and Sample Population - Fifty-two subjects (30 $; 22 #) participated in the TMJ load experiments. Material and Methods - In the absence of human tissue, pig TMJ discs were used to determine the effects of variables 1) on surface plowing forces, and to build a biphasic finite element model (bFEM) to test the effect of human joint loads and 2) on tissue stresses. In the laboratory, discs received a 7.6 N static load via an acrylic indenter before cyclic movement. Data were recorded and analysed using ANOVA. To determine human joint loads, Research Diagnostic Criteria calibrated investigators classified subjects based on signs of disc displacement (DD) and pain (+DD +pain, n = 18; +DD) pain, n = 17; -DD/-pain, n = 17). Three-dimensional geometries were produced for each subject and used in a computer model to calculate joint loads. Results - The combined effects of compressive strain, and aspect ratio and velocity of stress-field translation correlated with plowing forces (R2 = 0.85). +DD )pain subjects produced 60% higher joint loads (ANOVA, p < 0.05), which increased bFEM-calculated compressive strain and peak total normal stress. Conclusions - Static and dynamic variables of the stress-field and subjectdependent joint load significantly affect disc mechanics.
AB - Objectives - To determine the combined effects 1) of stress-field aspect ratio and velocity and compressive strain and 2) joint load, on temporomandibular joint (TMJ) disc mechanics. Setting and Sample Population - Fifty-two subjects (30 $; 22 #) participated in the TMJ load experiments. Material and Methods - In the absence of human tissue, pig TMJ discs were used to determine the effects of variables 1) on surface plowing forces, and to build a biphasic finite element model (bFEM) to test the effect of human joint loads and 2) on tissue stresses. In the laboratory, discs received a 7.6 N static load via an acrylic indenter before cyclic movement. Data were recorded and analysed using ANOVA. To determine human joint loads, Research Diagnostic Criteria calibrated investigators classified subjects based on signs of disc displacement (DD) and pain (+DD +pain, n = 18; +DD) pain, n = 17; -DD/-pain, n = 17). Three-dimensional geometries were produced for each subject and used in a computer model to calculate joint loads. Results - The combined effects of compressive strain, and aspect ratio and velocity of stress-field translation correlated with plowing forces (R2 = 0.85). +DD )pain subjects produced 60% higher joint loads (ANOVA, p < 0.05), which increased bFEM-calculated compressive strain and peak total normal stress. Conclusions - Static and dynamic variables of the stress-field and subjectdependent joint load significantly affect disc mechanics.
KW - Biphasic finite element model
KW - Cartilage
KW - Mechanics
KW - Plowing
KW - Temporomandibular joint
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U2 - 10.1111/j.1601-6343.2009.01449.x
DO - 10.1111/j.1601-6343.2009.01449.x
M3 - Article
C2 - 19627517
AN - SCOPUS:67349181386
SN - 1601-6335
VL - 12
SP - 159
EP - 167
JO - Orthodontics and Craniofacial Research
JF - Orthodontics and Craniofacial Research
IS - 3
ER -