The purpose of this article is to provide an update of the interrelationship between periodontics and orthodontics in adults. Specific areas reviewed are the reaction of periodontal tissue to orthodontic forces, the influence of tooth movement on the periodontium, the effect of circumferential supracrestal fiberotomy in preventing orthodontic relapse, the effect of orthodontic treatment on the periodontium, microbiology associated with orthodontic bands, and mucogingival and esthetic considerations. In addition, the relationship between orthodontics and implants (eg, using dental implants for orthodontic anchorage) is discussed.