Prediction of optimal bending angles of a running loop to achieve bodily protraction of a molar using the finite element method

• 발행기관: 대한치과교정학회
• 저자명: WoonKuk Ryu JaeHyun Park Kiyoshi Tai Yukio Kojima Youngjoo Lee JongMoon Chae
• 간행물 정보: 『The Korean Journal of Orthodontics』제48권 제1호, 3~10쪽, 전체 8쪽
• 주제분류: 의약학 > 기타의약학
• 파일형태: PDF
• 발행일자: 2018.01.31

영문 초록

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 threedimensional 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 9.6° and rotated counterclockwise by 5.4°. These angles were almost similar to those predicted by the beam theory. When the amount of tip-back and toe-in angles were 11.5° and 9.9°, respectively, bodily movement of the molar was achieved. When the bend angles were increased to 14.2° and 18.7o, the molar tipped distally by 4.9° and rotated clockwise by 1.5°. 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.

목차

INTRODUCTION

MATERIALS AND METHODS

RESULTS

DISCUSSION

CONCLUSION

ACKNOWLEDGEMENTS

REFERENCES

키워드

Finite element method Molar protraction Running loop Tip-back angle