MedElevator
Войти в исследования American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics · 2025
Biomechanical analysis of mandibular molar intrusion with or without an archwire constriction bend: A finite element study.
СтатьяНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Komaki Hiroya, Chae Jong-Moon, Park Jae Hyun, Hamanaka Ryo, Yoshida Noriaki
Аннотация
INTRODUCTION: This study aimed to analyze 3-dimensional (3D) tooth movement patterns during mandibular molar intrusion using finite element analysis, with a particular focus on the effects of temporary skeletal anchorage devices positioning and archwire constriction bend (ACB).
METHODS: A 3D finite element model of the mandibular dentition was constructed. Intrusive forces of 2.0 N were applied to the archwire either mesial (M6 model) or distal (D6 model) to the first molar, whereas bilateral forces of 1.0 N were applied in the MD6 model. An ACB force of 1.0 N was applied lingually to both ends of the archwire. Tooth displacement, angulation change, and occlusal plane rotation were evaluated in 3 dimensions after 100 cycles of bone remodeling simulation, both with and without ACB during molar intrusion.
RESULTS: Mandibular molars exhibited intrusion accompanied by mesial tipping in the M6 model, distal tipping in the D6 model, and minimal tipping in the MD6 model, regardless of the presence or absence of ACB. The mandibular central incisor (Mn1) demonstrated labioversion in the M6 model and linguoversion in both the D6 and MD6 models without ACB. With ACB applied, Mn1 consistently showed labioversion across all models, with the greatest intrusion and labioversion observed in the M6 model. The occlusal plane angle (OPA) rotated counterclockwise in all models except the M6 model with ACB, which exhibited a slight clockwise rotation. Mandibular posterior teeth showed buccal tipping in all models except the M6 model with ACB, where molars tipped lingually. ACB application reduced buccal tipping of the mandibular posterior teeth and mitigated counterclockwise rotation of the OPA, while promoting intrusion and labioversion of Mn1. Notably, OPA remained nearly stable during molar intrusion in the M6 model with ACB.
CONCLUSIONS: The appropriate force direction for mandibular molar intrusion, combined with ACB, facilitates controlled 3D tooth movement patterns.
METHODS: A 3D finite element model of the mandibular dentition was constructed. Intrusive forces of 2.0 N were applied to the archwire either mesial (M6 model) or distal (D6 model) to the first molar, whereas bilateral forces of 1.0 N were applied in the MD6 model. An ACB force of 1.0 N was applied lingually to both ends of the archwire. Tooth displacement, angulation change, and occlusal plane rotation were evaluated in 3 dimensions after 100 cycles of bone remodeling simulation, both with and without ACB during molar intrusion.
RESULTS: Mandibular molars exhibited intrusion accompanied by mesial tipping in the M6 model, distal tipping in the D6 model, and minimal tipping in the MD6 model, regardless of the presence or absence of ACB. The mandibular central incisor (Mn1) demonstrated labioversion in the M6 model and linguoversion in both the D6 and MD6 models without ACB. With ACB applied, Mn1 consistently showed labioversion across all models, with the greatest intrusion and labioversion observed in the M6 model. The occlusal plane angle (OPA) rotated counterclockwise in all models except the M6 model with ACB, which exhibited a slight clockwise rotation. Mandibular posterior teeth showed buccal tipping in all models except the M6 model with ACB, where molars tipped lingually. ACB application reduced buccal tipping of the mandibular posterior teeth and mitigated counterclockwise rotation of the OPA, while promoting intrusion and labioversion of Mn1. Notably, OPA remained nearly stable during molar intrusion in the M6 model with ACB.
CONCLUSIONS: The appropriate force direction for mandibular molar intrusion, combined with ACB, facilitates controlled 3D tooth movement patterns.