Interceptive Treatment, also known as Phase I, is a treatment that is usually based on "growth guidance". A Phase I treatment is used to correct a problem that may be caused by a harmful habit, such as thumb sucking or tongue thrusting, or an issue that is genetic in nature.
Interceptive Treatment is used to correct several problems such an a narrow palate, an open bite or a deep bite. All of these issues can affect how the adult teeth are able to come in. Correcting these problems early can help the adult teeth to come in properly. Taking advantage of growth is easiest on the patient. Guiding growth in a specific direction, the correct direction, will help the patient's dental development overall.
Having a Phase I does not mean that a patient will not need comprehensive treatment in the future. It usually means, however, that comprehensive treatment will be shorter and easier than it would have been if there wasn't a Phase I.
This Phase is usually done when a patient is between 6-10 years old and still has several baby teeth remaining.