Bimaxillary protrusion has a significant influence on facial esthetics and orthodontics plays an important role in its correction, since incisor retrusion allows major lip changes. In contemporary orthodontics this can be achieved, in varying degrees, by three basic mechanisms: interproximal reduction, full arch distalization using skeletal anchorage, or premolar extractions. In premolar extraction cases it is not yet clear if there is a difference in anchorage loss and therefore in the amount of incisor retraction with two-step or en-masse retraction mechanics. Three dimensional aspects of cases treated with such mechanics will be presented regarding occlusal and facial effects. Although bimaxillary protrusion has been traditionally looked at in a profile view by our profession, it will be shown that this malocclusion is of greater impact in the frontal view, being associated with perioral muscular contraction, which can suggest unrested facial expressions. This presentation will demonstrate that 3D analysis and frontal perception of bimaxillary protrusion can shed light to a whole new perspective on this malocclusion.
Understand the tridimensional differences of space closure on two-step and en masse retraction.
See the tridimensional effect of incisor retraction on the lips.
Recognize the impact of the bimaxillary protrusion in the frontal view on facial esthetics.