There is no reason why using a hyaluronic acid filler such as Juvederm should not be used after using Aquamid.Juvederm, unlike Aquamid is an absorbable filler and unlike Aquamid is FDA approved. Just keep in mind that in theory the Aquamid is still there so be conservative with the fillers.
Different types of fillers can and are used to fill in and create shape to the face. There should be no problem of having Juvederm injections, IMHO.