 The study evaluated pre- and post-treatment lateral cephalograms from 182 late mixed-intitian patients with Class 1 and Class 2 malocclusions, with or without crowding, to determine whether anteroposterior mandibular dentoalveolar and skeletal changes occurring with growth and a specific late mixed-intitian treatment approach are influenced by the required amount of incisal overbite correction. The study found that non-headgear patients who had very deep overbites reduced showed significantly greater forward movements at both point B and Pagonian when compared to patients with less required incisal overbite reduction. This finding supports the concept of unlocking dentoalveolar structures with early reduction of very deep incisal overbites in appropriate patients, suggesting that bite opening should be undertaken at least as early as the late mixed-intitian stage to provide an improved environment for the mandibular dentoalveolus as it moves forward with normal growth. This article was authored by Woods Michael.