Finite element analysis of equine incisor teeth. Part 1: determination of the material parameters of the periodontal ligament.

The research article is about a study conducted to determine the variations in the material properties, specifically Young’s Modulus, of the periodontal ligament (PDL) in equine incisor teeth. The research explored equine dentistry, focusing on PDL diseases prevalent in aged horses, and the reasons for their frequent occurrence, using finite element (FE) analysis.

Research Context

• The research was initiated due to frequent findings of periodontal diseases in aged horses, which can be attributed to excessive strains and stress within the PDL. This is especially prevalent in older horses with short, worn-out teeth due to the repetitive masticatory cycle.
• The study aims to understand the specifics of these strains and stresses using a computational method called finite element (FE) analysis. This method, however, requires a precise understanding of the material parameters, particularly for the PDL of equine incisor teeth, information about which was unavailable prior to this research.
• The study involved determining the equine-specific, age-dependent, and load-dependent Young’s modulus of equine incisors, which is a crucial material parameter for FE analysis.

Research Methodology

• The research included extracting the incisor jaw-regions of horses of different ages and slicing these specimens into 5mm thick samples.
• These samples were then intruded (or axially displaced into the alveolus) under experimental conditions while monitoring the load-displacement relationship.
• A high-resolution micro-computer tomography (μCT) technique was used to create three-dimensional models of these slice samples, with particular attention paid to accurately modelling the anatomy of the PDL.
• After obtaining these models, Finite Element (FE) calculations were executed, and comparisons between the FE results and the experimentally measured displacements were made to obtain the Young’s modulus of the PDL.

Research Findings

• The results of this study reveal a non-linear behaviour in the collagen fibres of the PDL and a high load dependency in the PDL’s Young’s modulus. This indicates that as the load on the PDL increases, the flexibility or strain capacity decreases.
• The findings suggest a need for further investigation into the strains and stresses within the PDL, teeth, and surrounding bone of the entire rostral aspect of the jaw to gain a comprehensive understanding of periodontal diseases in aged horses.