sentences:  These regiments may be controlled by a brigade headquarters (more typical in World War I) or directly subordinated to the division commander.By contrast, in a square division, there were typically two brigades of two regiments.Other structures are possible, such as a pentomic division, where the division commander controls five maneuver elements, which was used in the United States Army in the late 1950s, with the regiments replaced by combined arms battlegroups.