The answer to the questions in World J Orthod 2003;1:72–77, regarding changes in crown lengths and repositioning of the gingival margins by orthodontic extrusion and intrusion was interesting, and the statements were of clinical significance. However, extrusion of teeth is also known to be able to improve the hard tissue architecture of different types of bone defects in adults with varying degrees of periodontal tissue breakdown. Of particular interest to me in this regard are the potential possibilities to create increased volumes of alveolar bone in the vertical plane prior to placement of single-tooth implants. What do we presently know about the possibilities for such orthodontic ridge augmentation? —Ahmet Keles, Farmington, Connecticut, USA