Original Research ARTICLE
The mechanical effect of the periodontal ligament on bone strain regimes in a validated finite element model of a macaque mandible
- 1Biomedicine Discovery Institute, Monash University, Australia
- 2Department of Oral Biology, College of Dentistry, University of Illinois at Chicago, United States
- 3Department of Organismal Biology and Anatomy, Division of Biological Sciences, University of Chicago, United States
- 4Department of Basic Science, Touro University California, United States
The primary anatomical function of the periodontal ligament (PDL) is to attach teeth to their sockets. However, theoretical and constitutive mechanical models have proposed that during mastication the PDL redistributes local occlusal loads and reduces the jaw’s resistance to torsional deformations. These hypotheses imply that accurately modelling the PDL’s material properties and geometry in finite element analysis (FEA) is a prerequisite to obtaining precise strain and deformation data. Yet, many finite element studies of the human and non-human primate masticatory apparatus exclude the PDL or model it with simplicity, in part due to limitations in µCT/CT scan resolution and material property assignment. Previous studies testing the sensitivity of finite element models (FEMs) to the PDL have yielded contradictory results, however a major limitation of these studies is that FEMs were not validated against in vivo bone strain data. Hence, this study uses a validated and subject specific FEM to assess the effect of the PDL on strain and deformation regimes in the lower jaw of a rhesus macaque (Macaca mulatta) during simulated unilateral post-canine chewing. Our findings demonstrate that the presence of the PDL does influence local and global surface strain magnitudes (principal and shear) in the jaw. However, the PDL’s effect is limited (diff. ~200-300µε) in areas away from the alveoli. Our results also show that varying the PDL’s Young’s Modulus within the range of published values (0.07-1750 MPa) has very little effect on global surface strains. These findings suggest that the mechanical importance of the PDL in FE models of the mandible during chewing is dependent on the scope of the hypotheses being tested. If researchers are comparing strain gradients across species/taxa, the PDL may be excluded with minimal effect on results, but, if researchers are concerned with absolute strain values, sensitivity analysis is required.
Keywords: Finite Element Analysis, Mastication, Biomechanics, Rhesus monkey (Macaca mulatta), sensitivity analysis
Received: 15 May 2019;
Accepted: 27 Sep 2019.
Copyright: © 2019 Mehari Abraha, Iriarte-Diaz, Ross, Taylor and Panagiotopoulou. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Miss. Hyab Mehari Abraha, Biomedicine Discovery Institute, Monash University, Clayton, Australia, firstname.lastname@example.org
Dr. Olga Panagiotopoulou, Biomedicine Discovery Institute, Monash University, Clayton, Australia, Olga.Panagiotopoulou@monash.edu