Bilinear elastic property of the periodontal ligament for simulation using a finite element mandible model

Abstract

This study aimed to introduce a procedure for determining the bilinear elastic moduli (E1 and E2) of the periodontal ligament for a mathematical tooth model to analyse stress in the mandible. The bone and tooth morphology were scanned from a dry skull and an extracted intact tooth, respectively, and reconstructed in a three-dimensional finite element model. The model showed good agreement with previously reported in vivo premolar movement when an E1 for the first phase tooth movement of 0.05 MPa and an E2 for the second phase of 8.0 MPa with ε12 of 0.075 were adopted. The mandible model analysis indicated that a remarkably high maximum compressive stress in the cervical cortical bone and the tensile stress in areas of masticatory muscle attachment were found. Future stress analyses using a jaw model may follow the process of determination of bilinear moduli to enhance accurate simulation with less calculation time.

The Biomechanical Function of Periodontal Ligament Fibres in Orthodontic Tooth Movement

“…Katona & Qian [29]). The tooth root is surrounded by a uniform layer to represent the PDL, which is in turn surrounded by another uniform layer to represent the alveolar bone, both 0.2 mm thick [29], [32]. The tooth, PDL and alveolar bone components were then surrounded by a block to represent the mandibular bone.…”

“…This value would seem reasonable when compared to the vertical intrusion of 0.12 mm cited by Borák et al . [32] from an experiment by Kato [41]. To get the same displacement for the solid PDL model, it was found necessary to use a Young's modulus value of 12.2 MPa for the PDL layer (determined through the ANSYS optimisation facility).…”

Computer aided modelling to simulate the biomechanical behaviour of customised orthodontic removable appliances

“…The volume shell is then subtracted from the alveolar bone in order to define the PDL volume [24]. Finally, the bone modelling process has been performed by taking into account the division between cancellous and cortical bone, which has a mean thickness value of 0.25 mm around the teeth socket [25]. The bone volume, obtained by segmenting CBCT data, has been divided into two different regions, assuming an external layer with a 0.25 mm thickness as cortical bone and the inner part as cancellous bone (Figure 4).…”

Efecto de las fuerzas oclusales sobre el periodonto analizado por elementos finitos / Effect of occlusal forces over periodontium analyzed through finite elements

“…El modelo geométrico del diente y sus tejidos circundantes en el maxilar inferior se crearon por medio del programa de diseño asistido por computador CAD de Solidworks®, versión 2013, a partir de imágenes médicas y de medidas tomadas con calibrador de un diente real, tejidos blandos y hueso. El periodonto tiene dos porciones fibrosas: el ligamento periodontal y la unión cemento-dentina, estructuras que soportan y distribuyen las cargas (6,12,13,16). Se seleccionó la dentina como estructura del modelo que se iba a analizar, debido a que hace parte de las estructuras de apoyo de las fuerzas oclusales.…”

“…Adicionalmente, la fuerza oclusal puede variar en diferentes regiones del arco. Entre tanto, no es sorprendente que los datos de los valores de las fuerzas oclusales sea variable, ya que el complejo de la oclusión se encuentra en un movimiento dinámico (12)(13)(14)(15)(16)(17). Se consideró necesario realizar un estudio para analizar la anatomía, la magnitud y la dirección dentro del sistema estomatognático, a fin de sugerir los posibles efectos deletéreos relacionados con las fuerzas excesivas generadas en parafunción en la cavidad oral.…”