Abstract :
Objectives: This study aims to perform a comparative evaluation of sequential maxillary molar distalization using clear aligners in combination with micro-implants and Class II elastics for reinforcing anchorage. The goal is to assess the biomechanical effectiveness and outcomes of these methods in achieving distalization without unwanted tooth movements.
Materials and Methods: A finite element model (FEM) study was conducted using the CBCT data of a 21-year-old female patient with Class II malocclusion. The 3D model of the maxilla and maxillary dentition was created and meshed for simulation. Five sub-models were developed to represent different treatment scenarios: clear aligners alone (control), aligners with Class II elastics using buttons or precision cuts, and aligners with micro-implants combined with elastics. Each model simulated sequential molar distalization with static loading forces. Displacement and stress responses were analyzed to determine the effectiveness and control of tooth movements.
Results: The FEM simulations revealed that the use of clear aligners with Class II elastics and micro-implants enhanced molar distalization efficiency while minimizing mesial displacement of anchorage teeth. Models with precision cuts and micro-implants showed superior anchorage control, reducing unwanted tipping and rotation. The greatest displacement was observed in models using precision cuts with Class II elastics, while the least displacement occurred in the control models.
The study concluded that Class II elastics provide superior control over molar movement compared to micro-implants when used with clear aligners for sequential maxillary molar distalization. Precision cuts on aligners offer better anchorage reinforcement than buttons.
Keyword :
Class II elastics, Microimplants, Maxillary molar distalization, Finite element model (FEM)