Arch form and dimensional changes in orthodontics

Abstract

In the first part of this article arch dimensional changes related to growth and fixed appliance therapy were discussed. A trend towards greater acceptance of arch development and expansion has followed advances in orthodontic appliances and arch wires. Longitudinal studies have highlighted the relapse potential related to expansion of the transverse dimension, particularly the mandibular inter-canine width. In this paper the literature related to arch expansion is considered and its implications for treatment and retention protocols discussed.