Effect of force on alveolar bone surrounding miniscrew implants: a 3-dimensional microcomputed tomography study

Area of Science:

• Orthodontics
• Biomaterials Science
• Bone Biology

Background:

• Miniscrew implants are crucial for orthodontic anchorage.
• Understanding bone's response to miniscrew implant forces is essential for treatment optimization.
• The influence of force magnitude and direction on bone adaptation requires further investigation.

Purpose of the Study:

• To investigate bone adaptation to varying forces applied to miniscrew implants.
• To determine the effect of force direction on the bone surrounding miniscrew implants.

Main Methods:

• A randomized split-mouth design in 6 foxhound dogs compared loaded (200g or 600g) and unloaded miniscrew implants over 9 weeks.
• Microcomputed tomography (6 μm resolution) assessed bone volume fractions at different distances from the implant surface.
• Bone volume fractions were analyzed in compression and non-compression zones.

Main Results:

• Bone volume fraction was lower in the 6-24 μm layer compared to outer layers.
• Loaded miniscrew implants showed less cortical bone but more non-cortical bone than unloaded ones.
• Lower force (200g) resulted in greater non-cortical bone volume than higher force (600g); compression zones had higher bone volume.

Conclusions:

• Force application, magnitude, and direction significantly impact bone formation around miniscrew implants.
• Bone adaptation is complex, with distinct responses in cortical and non-cortical bone.
• Findings suggest that optimizing force parameters can enhance bone response around miniscrew implants.