Your last two answers in this column have considered orthodontic extrusion of individual teeth to improve the location of the labial marginal gingiva (WJO 2003;4:72–77) and relocating the alveolar bone for implant site development in a vertical direction (WJO 2003;4:168–173). To complete the picture, it would be prudent to mention and discuss the possibility of creating alveolar bone in the horizontal dimension. In cases of agenesis or previous extractions of permanent teeth, when the bone is atrophic, the insertion of implants is often not possible without surgical augmentation and grafting. However, when a tooth is moved through the alveolar process, new bone is formed around it, building up the alveolar process and thereby providing, in a biologic manner, optimal space for implants. Similarly, in cases of agenesis of the maxillary lateral incisors, the surgeon may get the best bone for implants if the canines are allowed to erupt close to the central incisors, and are then moved distally during the creation of space for the lateral incisors, as we have discussed elsewhere.1 Would you like to comment on what is the state-of-the-art regarding horizontal implant site development?