This document discusses various methods for opening a deep bite through intrusion or extrusion of incisors and posterior teeth. It describes Burstone's principles of intrusion using light continuous forces and sequential movement. Cetlin's intrusion arch and Mulligan's appliance are explained. Utility arches are discussed as a versatile way to intrude and align segments. The three-piece intrusion base arch is presented as a way to simultaneously intrude and retract flared incisors through segmented mechanics while controlling force direction along the tooth axis.