In patients with maxillary horizontal deficiency, maxillary collapse, nasal stenosis, arch length problem, temporomandibular disorder and in arch coordination prior to orthognatics, the use of rapid maxillary expansion (RME) has become an accepted initial step in comprehensive orthodontic treatment. On the other hand, in adults where maxillary horizontal deficiency is present particularly above 25 years of age only surgical facilitation of RME is applicable. In this case presentation, upon failure of conservative expension in the widening of adult maxilla at the midpalatal suture is accomplished by lateral maxillary corticotomies and a Hyrax RME device. Separation of the midpalatal suture was confirmed by occlusal radiographs and a diastema between the maxillary central incisors.

Keywords: Adult, rapid maxillary expansion, surgery