Prediction of optimal bending angles of a running loop to achieve bodily protraction of a molar using the finite element method
Ryu Woon-Kuk, 박재현, Tai Kiyoshi, Kojima Yukio, 이영주, 채종문,
소속 상세정보
( Ryu Woon-Kuk ) - Private practice
박재현 ( Park Jae-Hyun ) - A.T. Still University Arizona School of Dentistry & Oral Health Postgraduate Orthodontic Program
( Tai Kiyoshi ) - A.T. Still University Arizona School of Dentistry & Oral Health Postgraduate Orthodontic Program
( Kojima Yukio ) - Nagoya Institute of Technology Department of Mechanical Engineering
이영주 ( Lee Young-Joo ) - Wonkwang University School of Dentistry Department of Orthodontics
채종문 ( Chae Jong-Moon ) - Wonkwang University School of Dentistry Department of Orthodontics
Abstract
Objective: The purpose of this study was to predict the optimal bending angles of a running loop for bodily protraction of the mandibular first molars and to clarify the mechanics of molar tipping and rotation.
Methods: A three-dimensional finite element model was developed for predicting tooth movement, and a mechanical model based on the beam theory was constructed for clarifying force systems.
Results: When a running loop without bends was used, the molar tipped mesially by 9.6o and rotated counterclockwise by 5.4o. These angles were almost similar to those predicted by the beam theory. When the amount of tip-back and toe-in angles were 11.5o and 9.9o, respectively, bodily movement of the molar was achieved. When the bend angles were increased to 14.2o and 18.7o, the molar tipped distally by 4.9o and rotated clockwise by 1.5o.
Conclusions: Bodily movement of a mandibular first molar was achieved during protraction by controlling the tip-back and toe-in angles with the use of a running loop. The beam theory was effective for understanding the mechanics of molar tipping and rotation, as well as for predicting the optimal bending angles.
키워드
Finite element method; Molar protraction; Running loop; Tip-back angle
원문 및 링크아웃 정보
등재저널 정보