Effect of Mechanical Loading on Electrical Conductivity in Porcine TMJ Discs

• Published in: Journal of dental research Vol. 90; no. 10; pp. 1216 - 1220
• Main Authors: Kuo, J., Wright, G.J., Bach, D.E., Slate, E.H., Yao, H.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.10.2011; International Association for Dental Research
• Subjects: Animals; Biological and medical sciences; Biomechanical Phenomena; Compressive Strength; Dental Stress Analysis; Dentistry; Diffusion; Electric Conductivity; Fundamental and applied biological sciences. Psychology; Ion Transport; Male; Porosity; Research Reports; Skeleton and joints; Sus scrofa; Temporomandibular Joint Disc - physiology; Vertebrates: osteoarticular system, musculoskeletal system; solute transport; solute diffusivity; electrical conductivity; temporomandibular joint (TMJ) disc; cartilaginous tissue; tissue mechanics; Electrical conductivity; Electrical properties; Biological transport; Temporomandibular joint; Solutes; Diffusivity; Pig; Osteoarticular system; Biomechanics; Vertebrata; Mammalia; Mechanical stress; Animal; Artiodactyla; Porosity; Ungulata
• ISSN: 0022-0345; 1544-0591
• DOI: 10.1177/0022034511415275

The objective of this study was to examine the impact of mechanical loading on solute transport in porcine temporomandibular joint (TMJ) discs using the electrical conductivity method. The electrical conductivity, as well as ion diffusivity, of TMJ discs was determined under confined compression with 3 strains in 5 disc regions. The average electrical conductivity over the 5 regions (mean ± SD) at 0% strain was 3.10 ± 0.68 mS/cm, decreased to 2.76 ± 0.58 mS/cm (-11.0%) at 10% strain, and 2.38 ± 0.55 mS/cm (-22.2%) at 20% compressive strain. Correspondingly, the average relative ion diffusivity (mean ± SD) at 0% strain was 0.273 ± 0.055, decreased to 0.253 ± 0.048 (-7.3%) at 10% strain, and 0.231 ± 0.048 (-15.4%) at 20% compressive strain. These results indicated that compressive strain impeded solute transport in the TMJ disc. Furthermore, our results showed that the transport properties of TMJ discs were region-dependent. The electrical conductivity and ion diffusivity in the anterior region were significantly higher than in the posterior region. This regional difference is likely due to the significant differences of tissue hydration between these 2 regions. This study provides important insight into the electrical and solute transport behaviors in TMJ discs under mechanical loading and aids in the understanding of TMJ pathophysiology related to tissue nutrition.