Indian Board of Orthodontics Case Report: Orthodontic Management of a Class I Malocclusion with Bilateral Posterior Crossbite and Vertical Growth Pattern Using Maxillary Expansion Followed by Achieving Vertical Control Using Skeletal Anchorage and Ex

AT, a 14-year-old postpubertal female, presented with a Class I malocclusion and posterior crossbite on a Class II skeletal base with exaggerated backward rotation of the mandible on an apparently symmetrical face. The malocclusion showed crowding of 9 mm in the upper arch and 5 mm in the lower arch, bilateral posterior crossbite (crossbite tendency only with respect to molars on the right side), reduced intermolar width of 29 mm and wide buccal corridor, reduced overjet (0.5 mm) and shallow overbite (0.5 mm). The upper midline was shifted to the left side by 0.5 mm due to local crowding. An anterior crossbite was present in the 22 region, with a crossbite tendency with respect to 12. Individual tooth irregularities, such as labially erupted 13, 23 and mesiolabially rotated 33 and 43, were also noted. Treatment included correction of posterior crossbite with bonded Hyrax expander (semi-rapid expansion protocol) followed by extraction of all second premolars for alignment and levelling; and extraction of all third molars for vertical control using upper and lower pre-adjusted edgewise appliances (0.022” × 0.028” slot) with MBT prescription and skeletal anchorage.