Phase I treatment, or early interceptive treatment, is limited orthodontic treatment (i.e., expander or partial braces) before all of the permanent teeth have erupted. Such treatment can occur between the ages of 7 and 10. The goal of Phase I treatment is to intercept a moderate or severe orthodontic problem early in order to reduce or eliminate it. This treatment is sometimes recommended to make more space for developing teeth, correction of crossbites, overbites, underbites or harmful oral habits. Phase I treatment takes advantage of the early growth spurt and turns a difficult orthodontic problem into a more manageable one. This often helps reduce the need for extractions or surgery. Most Phase I patients require a second phase of treatment in order to achieve an ideal final bite.
Phase II treatment usually occurs a number of years later. We wait for the remaining permanent teeth to erupt, sometimes including second molars before Phase II treatment begins. This most commonly occurs at the age of 12 or 13. The goal of Phase II treatment is to achieve an ideal bite with all of the permanent teeth.
Not every child needs a Phase I treatment. Only some children with certain bites require early intervention. All others can wait until most, if not all, of their permanent teeth erupt for comprehensive one-step treatment. However, it is important that every child be evaluated.