With the 2011 season over, the Bengals no longer apply to the 53-man roster limit and the team can also dissolve their practice squad roster because, well, there's no need to have one.
However, the team still has a maximum roster limit of 80 players to stay under throughout the offseason, through training camp until late in the preseason when the roster limits are changed from 80, to 75 and then the 53-man roster you see in the regular and post seasons.
On Monday, the Bengals signed five players to their offseason roster from their practice squad. Those players are Guard Otis Hudson, Fullback James Develin, Offensive Tackle Andrew Gardner, Safety Cary Harris and Defensive End James Ruffin.