Japan Academy of Aligner Orthodontics 2016

Basic Research Background of Tooth Movement Examined by Aligner Orthodontics -Studies of Histological and Finite Element Simulation-

There are active tissue reactions due to orthodontic mechanical stress during orthodontic treatment. The mechanical stress causes bone remodeling mainly due to both activated osteoblasts and osteoclasts. The osteoblasts and osteoclasts cause both bone formation on the orthodontic tension side and bone resorption on the orthodontic pressure side. For establishing a pathological background of orthodontic treatment, many animal experiments have been performed. For examination of the histopathological changes and their repair, we examined the reactions of the mouse periodontal tissues after receiving the mechanical stress using Waldo method.
Next we tried to find out active tissue reactions due to orthodontic mechanical stress during aligner orthodontic treatment. If aligner orthodontic treatment enables optimal tooth movement, it has more advantages than conventional orthodontic treatments. However, unclear points still remain in the tooth movement patterns caused by aligner orthodontics. In addition, it was difficult to establish in Vivo method by using aligner orthodontics. In order to clarify tooth movement patterns caused by aligner orthodontics, we have conducted finite element simulation.
As a result the incisor was translated or rotated slightly, orthodontic tooth movements were simulated by the finite element method. At the same time axial rotation of the incisor was almost achieved. In the case of mesial translation, the crown moved to the predicted position but the root apex hardly moved. Slight intrusion of the incisor was achieved, but extrusion was almost impossible. Therefore, further research is required for our next examination.
This presentation has been conducted by following institutions, Matsumoto Dental University, Aichi-Gakuin University and Nagoya Institute of Technology.