Comparison of Infrazygomatic Crest Mini-Implant and Inter-Radicular Mini-Implant as Skeletal Anchorage when used for En Masse Anterior Retraction and En Masse Distalization - A Fem Study

Introduction: This paper describes a finite element model study comparing infrazygomatic crest mini-implants with inter-radicular mini-implants for both En Masse retraction of anterior teeth and En masse distalization of the upper dentition. Aim: The main objectives of this study were to examine the forces on the bone generated by the alternative biomechanic systems of anterior retraction or en masse distalization. Design: Finite element analysis. Setting: Department of orthodontics. Material and Methods: Finite element models of maxillary anterior teeth and surrounding bone were constructed from CT scans Main outcome methods: FEM model was used to simulate the force levels and direction using the two alternative mini-implant systems under investigation. Results: There was no significant difference between the force levels used in infrazygomatic crest mini-implants compared to inter-radicular mini-implants. Maximum distalization was achieved when the infrazygomatic crest mini-implants were placed at 70 degrees. The infrazygomatic crest mini-implants were more effective in en masse distalization of the maxillary dentition. If both intrusion and retraction are indicated infrazygomatic mini-implants are a better choice than inter-radicular mini-implants. Conclusions: The infrazygomatic crest mini-implants were more effective in en masse distalization of the maxillary dentition. If both intrusion and retraction are indicated infrazygomatic mini-implants are a better choice than inter-radicular mini-implants.