IADR Abstract Archives
Native Properties in a Growing Porcine Temporomandibular Joint
Objectives: The porcine model is the gold standard for large animal temporomandibular joint (TMJ) research. However, in vivo studies are performed before the animal reaches skeletal maturity, creating the potential need for multiple control groups to account for the potential effects of aging. This highlights the need for a study examining native properties at varying time points during the porcine aging process. The objective of this study was to determine the mechanical and biochemical properties of the porcine TMJ disc at 3, 6, and 9 months.
Methods: Female pigs at 3, 6, and 9 months old were obtained from a local abattoir, and both TMJ discs were immediately excised. Samples were analyzed for biochemical properties (collagen, glycosaminoglycan (GAG), and DNA content), uniaxial tensile properties, and uniaxial stress relaxation compressive properties. All parameters were compared with a one-way ANOVA with a tukey’s post hoc test with α < 0.05.
Results: Collagen content for native discs at 3 months (49 ± 26%/DW) was significantly lower (p < 0.05) than at 6 months (80 ± 6%/DW) and 9 months (80 ± 13%/DW). No differences were detected (p < 0.05) in GAG or DNA content for any time points. For compression testing, the peak stress at 3 months (42 ± 35 kPa) was significantly lower (p < 0.05) than at 9 months (113 ± 58 kPa), but not 6 months (90 ± 22 kPa). The compressive modulus for 3 months (542 ± 429 kPa) was significantly lower (p < 0.05) than at both 6 months (1225 ± 260 kPa) and 9 months (1369 ±596 kPa). No significant differences were seen for uniaxial tensile testing for tensile stress and tensile modulus.
Conclusions: The differences observed in collagen content and compressive properties highlight the need for using age-matched controls in in vivo research using varying time points.
Methods: Female pigs at 3, 6, and 9 months old were obtained from a local abattoir, and both TMJ discs were immediately excised. Samples were analyzed for biochemical properties (collagen, glycosaminoglycan (GAG), and DNA content), uniaxial tensile properties, and uniaxial stress relaxation compressive properties. All parameters were compared with a one-way ANOVA with a tukey’s post hoc test with α < 0.05.
Results: Collagen content for native discs at 3 months (49 ± 26%/DW) was significantly lower (p < 0.05) than at 6 months (80 ± 6%/DW) and 9 months (80 ± 13%/DW). No differences were detected (p < 0.05) in GAG or DNA content for any time points. For compression testing, the peak stress at 3 months (42 ± 35 kPa) was significantly lower (p < 0.05) than at 9 months (113 ± 58 kPa), but not 6 months (90 ± 22 kPa). The compressive modulus for 3 months (542 ± 429 kPa) was significantly lower (p < 0.05) than at both 6 months (1225 ± 260 kPa) and 9 months (1369 ±596 kPa). No significant differences were seen for uniaxial tensile testing for tensile stress and tensile modulus.
Conclusions: The differences observed in collagen content and compressive properties highlight the need for using age-matched controls in in vivo research using varying time points.