An experimental study on the stress distribution in the periodontal ligament.
- Author:
Kwang Chul CHOY
1
;
Kyung Ho KIM
;
Young Chel PARK
;
Jung Yun HAN
Author Information
1. Department of Orthodontics, College of Dentistry, Yonsei University, Korea. kchoy@yumc.yonsei.ac.kr
- Publication Type:Original Article
- Keywords:
periodontal ligament;
stress distribution;
center of resistance;
center of rotation
- MeSH:
Axis, Cervical Vertebra;
Models, Theoretical;
Periodontal Ligament*;
Tooth;
Tooth Movement
- From:Korean Journal of Orthodontics
2001;31(1):15-24
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
In order to achieve a desirable tooth movement, it is of great importance to control the M/F ratio and to know the location of the center of resistance. The purpose of this study was to locate the center of resistance and the axis of rotation, and to estimate the stress distribution in the periodontal ligament with experimental model. After preparing a model of an upper canine with a simulated periodontal ligament and alveolar bone, the force and moment were applied. The tooth movement was traced using measuring device with LVDTs(Linear variable differential transformers) that can measure three dimensional tooth movement in real time. The results were as follows. 1. The location of center of resistance by transverse force was 29% of root length measured from alveolar crest to apex regardless of force magnitude. The position of the center of resistance is more coronal than that of two-dimensional model(42%). 2. The center of resistance and the axis of rotation coincide when couple moment was applied. 3. As the magnitude of moment increases, tooth tends to extrude irrespective of the direction of the moment. 4. The relationship between location of force and axis of rotation (a x b =49.6mm2) was obtained. A tooth movement can be predicted through this formula. 5. The centers of rotation by transverse force were plotted linearly.
