Phase I, or early treatment, can be limited orthodontic tooth movement, dental orthopedic correction of the jaws or a combination of both. Limited orthodontic tooth movement can be done with partial braces or specially designed removable appliances before all of the permanent teeth have erupted. Dental orthopedic corrections are treatments to improve the relationships of the upper and lower jaws to each other. The appliances generally attach to the teeth, but are designed to transfer their action to the jaws. Such treatment often occurs between the ages of six and ten. These treatments are recommended to make more space for developing teeth, correction of crossbites, overbites, large overjets, underbites or harmful oral habits.
Phase II treatment is also called comprehensive treatment because it involves full braces or Invisalign when all of the permanent teeth have erupted, usually between the ages of ten and thirteen.