SDN Members don't see this ad. (About Ads) I was recently looking on the Army's Human Resources Command Website and came across a list of projected available assignments for 2012 and 2013. They are listed under three columns. Tier 1, Tier 2, and Dental Clinic Commands. What's the difference between the three? Can anyone out of dental school go to any category or do some require the AEGD or more experience?