A rodent model using skeletal anchorage and low forces for orthodontic tooth movement

Area of Science:

• Biomedical Engineering
• Orthodontics
• Animal Models

Background:

• Nonhuman animal models are crucial for studying orthodontic tooth movement (OTM).
• Rodent models often show reduced bone volume during OTM, posing limitations.
• A need exists for reliable models to study OTM with minimal bone loss.

Purpose of the Study:

• To assess the efficacy of a skeletal anchorage system for OTM in rats.
• To investigate the impact of low orthodontic force (3 cN) on interradicular bone volume.
• To validate a novel rat model for OTM research.

Main Methods:

• Ninety Sprague-Dawley rats underwent OTM using a miniscrew and nickel-titanium coil spring (3 cN experimental, 0 cN sham).
• A split-mouth design was employed, with measurements taken at five time points.
• Tooth displacement and interradicular bone volume/total volume (BV/TV) were quantified.

Main Results:

• Miniscrew success rate was high at 98.9%.
• Consistent linear and angular tooth movement was observed (0.1 mm/wk).
• BV/TV reduction in the 3 cN group was less pronounced than in previous studies.

Conclusions:

• The developed skeletal anchorage model enables efficient OTM in rats.
• The model demonstrated minimal reduction in interradicular bone volume.
• This validated model provides a foundation for future orthodontic research.