Comparative Analysis of Dentoalveolar Effects Induced by Various Fixed Functional Appliances: A Three-Dimensional...

Area of Science:

• Orthodontics
• Biomechanical Engineering
• Dental Mechanics

Background:

• Class II Division 1 malocclusion requires effective orthodontic treatment.
• Fixed functional appliances are used to correct this malocclusion.
• Quantifying dentoalveolar effects of different appliances is crucial for treatment planning.

Purpose of the Study:

• To quantify the dentoalveolar effects of three fixed functional appliances: PowerScope2, Forsus Fatigue Resistant Device (FFRD), and Herbst.
• To compare the biomechanical responses of these appliances using the finite element method.
• To analyze stress distribution and tooth displacement patterns during Class II correction.

Main Methods:

• Generated 3D finite element models of the mandible, maxilla, and skull from CBCT scans.
• Simulated the PowerScope2, FFRD, and Herbst appliances on the dental arches.
• Applied forces to the models and calculated Von Mises and principal stresses and tooth displacements.

Main Results:

• All appliances caused distal movement of maxillary teeth and mesial movement of mandibular teeth.
• The Herbst appliance resulted in the greatest maxillary distalization and highest stress values.
• The PowerScope2 showed the greatest mandibular mesialization.

Conclusions:

• The Herbst appliance simulation produced the highest stress and minimal initial mandibular displacement, suggesting potential for reduced dentoalveolar movement.
• The Herbst appliance demonstrated a more pronounced initial distalizing effect on maxillary teeth.
• Findings require clinical validation due to static muscle force assumptions in the model.