On the CONDITIONS toolbar on right side click the MISSING icon. (it looks like a grayed out tooth) Now click the graphic of the baby tooth. (not the toggle switch)
The Adult tooth graphic will now appear. If the adult tooth is present in the patient's mouth, then remove the "Unerupted" condition from the adult tooth. Look in the "Other Conditions" list for Unerupted, double-click it to select, and then click the adult teeth that have erupted.