In one of my recent cases, I used active intrusion of two maxillary central incisors to reposition their gingival margins in an apical direction. These teeth were then restored with porcelain laminate veneers, and the final result was esthetically improved with regard to both clinical crown lengths and labial marginal gingival levels. This case indicates to me that orthodontic treatment can contribute to results that are difficult, if not impossible, to obtain by other means of esthetic dentistry. Furthermore, a recent AJODO article1 from a team in Hong Kong demonstrated that the labial gingival margin of a maxillary canine substituting for a congenitally missing lateral incisor was moved almost 9 mm incisally by means of orthodontic extrusion. These cases imply that the potential of an orthodontist in improving gingival levels may often be overlooked by other dentists. As far as I know, most research on orthodontic intrusion and extrusion of teeth has dealt with tissue reactions other than changes of the gingival levels. What is actually the present knowledge or state-of-the-art when it comes to changes in crown lengths and repositioning of gingival levels associated with tooth movements in the vertical plane? —Arni Thordarson, Reykjavik, Iceland