Great Question! Expansion is the process of creating growth change — usually to help alleviate crowding which most often prevents the need for extractions. Expansion also can correct a dental cross bite where the back teeth fit inside of the lower back teeth.
Not all cross bites, however, require a growth change. Often, the back teeth are tipped to fit inside the lower back teeth. In this case, we simply need to upright the upper molars cheek-wise to make the correction.
We make the decision on whether to expand by measuring the width of the upper front teeth and the width of the jaw at the upper 1st permanent molars. The upper jaw should be 35 to 40 millimeters for us to obtain a stable result. So we actually measure to make sure there is a proper proportionality. James McNomara has been teaching this diagnostic method since the late 1980’s and did a voluminous study to create these guidelines called the Michigan study.
The types of upper jaw expanders vary greatly! For young children (ages 6-11) we prefer to use our press-on expanders whereby the patient does not have to wear a jack-screw appliance. Our method is virtually painless and you can learn all about them on our website. Please visit our treatment options tab to learn more.