The Finite Element Method: a Tool to Study Orthodontic Tooth Movement

TLDR

Orthodontic tooth movement relies on alveolar bone remodeling driven by stress/strain changes in the periodontium, and the finite element method has been employed to model the stress distribution in the periodontal ligament and surrounding bone. The study aimed to determine how modeling choices affect finite element outcomes and relate these to current theories of orthodontic tooth movement. The authors performed a series of finite element analyses simulating orthodontically loaded teeth, varying geometry/morphology, material properties, and boundary conditions. Accurate modeling of alveolar bone morphology and nonlinear mechanical properties of the PDL elements shows that periodontium loading cannot be explained simply by compression and tension along the loading direction, with tension in the alveolar bone being far more predominant than compression.

Abstract

Orthodontic tooth movement is achieved by (re)modeling processes of the alveolar bone, which are triggered by changes in the stress/strain distribution in the periodontium. In the past, the finite element (FE) method has been used to describe the stressed situation within the periodontal ligament (PDL) and surrounding alveolar bone. The present study sought to determine the impact of the modeling process on the outcome from FE analyses and to relate these findings to the current theories on orthodontic tooth movement. In a series of FE analyses simulating teeth subjected to orthodontic loading, the influence of geometry/morphology, material properties, and boundary conditions was evaluated. The accurate description of alveolar bone morphology and the assignment of non-linear mechanical properties for the PDF elements demonstrate that loading of the periodontium cannot be explained in simple terms of compression and tension along the loading direction. Tension in the alveolar bone was far more predominant than compression.