Lack of sufficient anchorage often sets the limit for what can be reached with conventional orthodontics. If undesirable side effects can be transferred to skeletal anchorage the application of the correct force system directly to the teeth that should be displaced can be performed. Treatment planning can focus on the definition of the correct force system necessary for the desired displacement and biomechanical knowledge can be used for design of optimal appliances. Treatment possibilities can not only be widened, but the treatments can also be more efficient and with less iatrogenic results if skeletal anchorage is applied where indicated. The focus will be on the biomechanical possibilities given by the skeletal anchorage.