Rare earth magnets and impaction.

Area of Science:

• Biomaterials Science
• Orthodontics
• Biotechnology

Background:

• Tooth impaction is often caused by eruption abnormalities.
• Conventional traction methods can lead to gingival inflammation, bone recession, and root resorption due to uncontrolled forces and premature tooth exposure.

Purpose of the Study:

• To introduce and evaluate a novel magnetic attraction system for treating impacted teeth.
• To mimic natural tooth eruption pathways and mitigate side effects associated with traditional methods.

Main Methods:

• A magnetic bracket bonded to the impacted tooth and an intraoral magnet attached to a retainer were designed.
• Vertical and horizontal magnetic brackets were developed for different tooth types.
• A 3D analysis of the magnetic force system was performed using the OMSS apparatus.
• The system was tested on one animal subject and four patients, with magnets coated or encapsulated for biocompatibility.

Main Results:

• The magnetic system demonstrated efficient convergent guidance, particularly with a small bracket and large magnet pole surface area.
• Tooth emergence into the oral cavity mimicked natural eruption conditioning.
• The system operated at an attractive force of 0.2 to 0.5 N.
• No adverse side effects were observed in the treated cases, and treatment duration was reduced.

Conclusions:

• The magnetic attraction system presents a promising, less invasive approach to managing impacted teeth.
• It offers controlled spatial guidance and effective attractive forces at short distances.
• Further application of magnets in impaction treatment is recommended due to its benefits over conventional methods.