Maxillary expansion has been carried out for more than a century. The prime objective of palatal expansion is to coordinate the transverse dimensions of maxillary and mandibular denture bases. Expansion of narrow or collapsed maxillary arches has been performed in many different ways and may be achieved through tooth movement (orthodontic), orthopedic movement (bony), or a combination of the two. A wide range of appliances are used: fixed, semi-fixed, and removable.