title: Effect of mechanical strain on solute diffusion in human TMJ discs: an electrical conductivity study.
abstract: This study investigated the effect of mechanical strain on solute diffusion in human TMJ discs (mean cadaver age 77.8) using the electrical conductivity method. The electrical conductivity, as well as small ion diffusivity, of male and female TMJ discs was determined under three compressive strains. In the male group, the average disc electrical conductivity (mean ± SD) at 0% strain was 5.14 ± 0.97 mS/cm, decreased to 4.50 ± 0.91 mS/cm (-12.3%) at 10% strain, and 3.93 ± 0.81 mS/cm (-23.5%) at 20% compressive strain. Correspondingly, the average disc relative ion diffusivity at 0% strain was 0.44 ± 0.08, decreased to 0.40 ± 0.08 (-8.9%) at 10% strain, and 0.36 ± 0.08 (-16.7%) at 20% compressive strain. In the female group, the average disc electrical conductivity at 0% strain was 5.84 ± 0.59 mS/cm, decreased to 5.01 ± 0.50 mS/cm (-14.2%) at 10% strain, and 4.33 ± 0.46 mS/cm (-25.8%) at 20% compressive strain. Correspondingly, the average disc relative ion diffusivity at 0% strain was 0.49 ± 0.05, decreased to 0.43 ± 0.04 (-11.3%) at 10% strain, and 0.39 ± 0.04 (-19.9%) at 20% compressive strain. The results indicated that mechanical strain significantly impeded solute diffusion through the disc. This mechanical strain effect was larger in the female than in the male human TMJ disc. This study may provide new insights into TMJ pathophysiology.
authors.affiliation: Clemson-MUSC Bioengineering Program, Department of Bioengineering, Clemson University, 173 Ashley Avenue, P.O. Box 250508, Charleston, SC, 29425, USA.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Wright
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kuo
authors.forename: Changcheng
authors.initials: C
authors.lastname: Shi
authors.forename: Thierry R H
authors.initials: TR
authors.lastname: Bacro
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Slate
authors.forename: Hai
authors.initials: H
authors.lastname: Yao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D019245:Compressive Strength; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007477:Ions / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D012727:Sex Characteristics; D019224:Temporomandibular Joint Disc / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology
chemical_list: D007477:Ions