[Upper central incisors and asymmetry: a significant orthodontic challenge].

In any assessment of the esthetic characteristics of a smile the central incisors play a decisive role. Moreover, correction of their malpositions and, especially, their asymmetry, is one of the principal reasons patients consult orthodontists. The etiology of this asymmetry may be vertical, with one incisor more erupted than its mate or horizontal, with a mid-line discrepancy, and can be objectified by a clinical examination and supplementary studies, especially radiological as a means of helping orthodontists adopt the most appropriate treatment plan. In accordance with the etiopathogenesis of the malocclusion, alveolo-dental trauma, skeletal asymmetry, or asymmetry of arches, the orthodontic treatment may be undertaken on three levels, with the teeth themselves by extrusion, intrusion, or rotation; regionally with the arches by retraction of teeth en masse; or globally at the skeletal level with maxillo-facial surgery. The complexity of some treatment in relation to the coordination of different levels of therapeutic action is intensified by the occasional necessity of obtaining collaboration of other specialists like general dentists, periodontists, and maxillo-facial surgeons. In such cases the initial treatment plan takes on increased importance, as does the choice of collaborating colleagues. However, once successfully completed these complicated treatments become a source of great satisfaction both for practitioners and for patients because of the enormous improvement that has been obtained.