Optimized orthodontic palatal miniscrew implant insertion angulation: a finite element analysis

Area of Science:

• Orthodontics
• Biomaterials Engineering
• Biomechanics

Background:

• Optimal insertion angulation of orthodontic miniscrews for skeletal anchorage remains debated.
• Miniscrews are vital for anchorage in various orthodontic treatments.

Purpose of the Study:

• To investigate the effect of different miniscrew insertion angulations on stress and strain distribution in bone models.
• To determine the optimal angulation for minimizing mechanical stress and deflection during orthodontic force application.

Main Methods:

• A 8-mm miniscrew was virtually inserted at various angles (30-150 degrees) into a bilayer bone model simulating normal and osteoporotic conditions.
• Finite element analysis was used to calculate von Mises stress, microstrain, and deflection under a 2N horizontal force.
• Cone beam computed tomography (CBCT) data from a human palate was used to create the bone model.

Main Results:

• Cancellous bone experienced lower stress than cortical bone.
• Osteoporotic bone models showed higher strain values.
• The 30-degree insertion angulation resulted in the lowest stress and strain in cortical bone and the miniscrew.
• The 30-degree model also exhibited minimal bone and miniscrew deflection.

Conclusions:

• A 30-degree miniscrew insertion angulation, directed towards the applied force, effectively reduces cortical bone stress and strain.
• This angulation may enhance the stability and success of orthodontic miniscrew anchorage, particularly in compromised bone quality.