Annals of Biomedical Engineering

, Volume 36, Issue 5, pp 801–812

Mode I and Mode III Fractures in Intermediate Zone of Full-Thickness Porcine Temporomandibular Joint Discs

Authors

    • Department of Adult Restorative DentistryUniversity of Nebraska Medical Center College of Dentistry
    • Department of Oral BiologyUniversity of Nebraska Medical Center College of Dentistry
  • Rebecca H. Hohl
    • Department of Growth and DevelopmentUniversity of Nebraska Medical Center College of Dentistry
  • Jeffrey C. Nickel
    • Department of Oral Biology, Division of Orthodontics, Dentofacial Orthopedics Graduate StudiesUniversity of Missouri – Kansas City
  • Laura R. Iwasaki
    • Department of Oral Biology, Division of Orthodontics, Dentofacial Orthopedics Graduate StudiesUniversity of Missouri – Kansas City
  • Ramana M. Pidaparti
    • Department of Mechanical EngineeringVirginia Commonwealth University
Article

DOI: 10.1007/s10439-008-9436-9

Cite this article as:
Beatty, M.W., Hohl, R.H., Nickel, J.C. et al. Ann Biomed Eng (2008) 36: 801. doi:10.1007/s10439-008-9436-9

Abstract

The aim of this study was to assess the critical energy required to induce flaw propagation in the temporomandibular joint (TMJ) disc when tensile and shear stresses were applied. J-integrals were measured for Mode I and III fractures because excessive tensile and shear stresses promote disc failure. Single edge notch (Mode I) and trouser tear (Mode III) specimens were constructed with flaws oriented parallel to the predominant anteroposteriorly oriented collagen fibers of the TMJ disc. Disks with and without an impulsive pre-load of 3 N s were studied to compare impact-damaged and healthy tissues. Results demonstrated that impulsive loading stiffened the tissues and significantly increased the Mode I fracture energy (JIC) but not Mode III (JIIIC) (p ≤ 0.05). JIC and JIIIC values were similar for undamaged tissues, but JIC values were 2.3 times higher for impulsively loaded tissues (p ≤ 0.05). This suggests that when flaws are introduced through impact, the TMJ disc responds by requiring more energy for tensile flaw extension. This research is a first step towards characterizing the mechanical microenvironment that initiates joint disease. This characterization is essential for successful integration of engineered replacement tissues for damaged TMJs.

Keywords

CartilageJ-integralImpact damageFracture mechanics

Copyright information

© Biomedical Engineering Society 2008