This investigation explores the biomechanical response of titanium mini-implants (Ti6Al4V) subjected to various orthodontic loading conditions using finite element analysis (FEA). The purpose is to assess their strength, fatigue resistance, and structural reliability under clinically relevant forces. Appropriate force magnitudes are essential for maintaining implant durability and preventing deleterious stress transmission to surrounding bone tissues. A standard titanium MI (2.0 mm in diameter, 12 mm in length) was modeled and analyzed in an FEA framework. The mandibular structure was reconstructed from computed tomography (CT) data using SpaceClaim 2023.1 and meshed into 10-node tetrahedral elements in ANSYS Workbench. Material constants were defined based on published data, and the bone–implant interface was simulated through a nonlinear frictional contact model. Orthodontic loads of 2 N and 10 N, each applied at a 30° inclination, were tested to replicate actual treatment conditions. Mechanical outputs—including total deformation, von Mises stress, equivalent strain, fatigue life, and safety factors—were examined to evaluate overall implant performance. At a load of 2 N, displacement was minimal (0.0328 mm), and the model sustained approximately 445,000 loading cycles within safe fatigue limits, maintaining a safety factor of 4.8369. Under a 10 N load, however, the implant endured only 1546 cycles before predicted failure, accompanied by increased stress (6.468 × 10⁵ MPa) and concentrated strain zones—suggesting a higher likelihood of structural failure and bone overload. The simulations identified a force threshold beyond which mechanical stability and peri-implant health deteriorate. Findings confirm that maintaining orthodontic forces near 2 N maximizes implant lifespan and preserves bone integrity. Conversely, excessive loads (around 10 N) drastically shorten service life and raise the risk of mechanical or biological complications. These outcomes underscore the importance of carefully calibrated force application to enhance the efficiency and longevity of orthodontic mini-implants.
