Load transfer across a mandible during a mastication cycle: The effects of odontogenic tumour

Abstract

The extent to which load transfer in a diseased mandible with odontogenic tumour might influence the potential risk of pathological fracture has scarcely been investigated. The study sought to investigate the quantitative deviations in load transfer across healthy and cancer-affected (diseased) mandibles having odontogenic tumours. The effect of size of the tumours (small: 9 mm diameter, large: 19 mm diameter), and variation in bone mechanical (elastic) properties of the mandible on load transfer in cancer-affected mandibles during a mastication cycle have been investigated. Based on patient-specific computed tomography–scan datasets, detailed three-dimensional finite element models of healthy and diseased mandibles were developed. High stresses of 25–30 MPa and strains ∼700 µε were observed in the healthy mandible during the right molar bite. However, marginal deviations were observed in principal stress distributions in the diseased mandibles with small- and large-sized tumours, as compared to the healthy mandible. Maximum principal strains of ∼1474 µε were found in the body region adjacent to the symphysis region for small-sized tumour. Whereas for large-sized tumour, maximum strains of ∼2700 µε were observed in the right buccal regions. Reduction in Young’s modulus due to different stages of odontogenic tumours had a localised effect on the principal stress distributions, but triggered an abrupt increase in the principal tensile strains. It appears that there is a potential risk of pathological fracture for large-sized odontogenic tumour, owing to high tensile stresses and strains.

Biomechanical influence of plate configurations on mandible subcondylar fracture fixation: a finite element study

“…In all the load cases, high tensile and compressive strains (~700-940 με) were observed. These strain levels were comparable with those reported in earlier studies 21, 24 having similar boundary and loading conditions. These corroborations provided confidence in the developed FE models.…”

“…The predictions of the developed FE model were qualitatively compared with previously published clinical and experimental studies. Despite the differences in the absolute magnitudes of stresses and strains 21, 24 , there was overall similarity in terms of magnitudes and location of the strains and stresses in the mandible between our FE predictions and previous publications 21, 24 which provide confidence in our FE predictions. The difference in the absolute magnitudes of stresses and strains between our FE predictions and previous publications could be attributed towards the variations in mandibular shape and material properties.…”

Biomechanical comparison of plate materials and designs for subcondylar fracture fixation: Anin silicoassessment

“…All the solid models of components, including the soft tissues, were discretized with a 10-noded tetrahedral element (SOLID 187) [24]. A 0.2 mm thick PDL layer was included due to the notable impact of the PDL on the load transfer from the teeth to the bone [22, 25]. Two blocks representing the temporal bone were modelled with 20×15×15 mm 3 having a concave depression [25, 26].…”

“…A 0.2 mm thick PDL layer was included due to the notable impact of the PDL on the load transfer from the teeth to the bone [22, 25]. Two blocks representing the temporal bone were modelled with 20×15×15 mm 3 having a concave depression [25, 26]. The condylar fibrocartilage, a soft tissue layer of 0.3 mm thickness, was attached to the depression [25, 26].…”

“…Two blocks representing the temporal bone were modelled with 20×15×15 mm 3 having a concave depression [25, 26]. The condylar fibrocartilage, a soft tissue layer of 0.3 mm thickness, was attached to the depression [25, 26]. A mesh convergence study was performed and mesh sizes were chosen for the model having <1% deviation in the state of stresses and strains [22].…”