Abstract
OBJECTIVE: The study used finite element analysis (FEA) to assess and quantify anchorage loss during simultaneous retraction and intrusion with or without anterior mini-implants under different forces. MATERIALS AND METHODS: CBCT scans of a skeletal Class I patient were used. Mimics Research 18.0 was used to construct a maxilla 3D model from scans. FEA was done with ANSYS 2024 R2 employing a model with bilateral mini-screws and a control model without mini-screws. Each model received a 100g retraction force and additionally vertical intrusive forces 90 g, 120 g, and 150 g in model 2. Both models were limited to the superior maxilla and had appliance component glued connections. RESULTS: FEA indicated that simultaneous intrusion and retraction enhanced maxillary first molar anterior displacement. The least displacement (6.24E-06 mm) occurred in model without mini-implants, while maximum displacement (6.86E-06 mm) in model with bilateral mini-implants with highest intrusive force. CONCLUSION: This study showed that conventional retraction without intrusive forces minimizes anchorage loss. With increasing force magnitude of intrusion, anterior molar displacement also increases.