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Updated: Aug 23, 2025
Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Biomechanical analysis of maxillary anterior teeth movements during different retracting methods with a lever arm
Dongcai Wang1,2, Boxiu Li3, Yi Xu3
1College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, China.
Objective:
The objective of the study was to find the most effective retracting method for the six maxillary anterior teeth with double-slot lingual brackets using a lever arm and miniscrew system.
Methods:
Six finite element models were constructed: (A) a ribbon-wise archwire with a lever arm; (B) a ribbon-wise archwire with a lever arm and a sectional edgewise archwire; (C) a ribbon-wise archwire and a sectional edgewise archwire with a lever arm; (D) an edgewise archwire with a lever arm; (E) an edgewise archwire with a lever arm and a sectional ribbon-wise archwire; and (F) an edgewise archwire and a sectional ribbon-wise archwire with a lever arm. Initial displacements of maxillary teeth driven by a 1.5 N retraction force to the lever arm were analysed.
Results:
In models B, C, E and F, anterior torque loss and inter-canine distance increases were significantly lower than that of the models without auxiliary archwires. In models C and F, the main archwire was less likely deformed. In models A, B and C, the displacement of canines in sagittal and vertical directions were less than in models D, E and F.
Conclusions:
The combination of edgewise and ribbon-wise archwires in double-slot lingual brackets effectively preserves the anterior arch shape. An edgewise archwire with lever arms on the auxiliary sectional ribbon-wise archwire is recommended for better performance in anterior teeth retraction.
