Patients with cleft lip and palate (CLP) related deformities frequently have maxillary hypoplasia in all dimensions. These patients usually present with class III malocclusions, retruded midfaces and narrow hard palates. The skeletal problems can be treated by means of Le Fort I maxillary procedures. Surgical and orthodontic correction of severe maxillary hypoplasia, as often seen in CLP patients, has however proved to be challenging. The magnitude of the advancement is often hampered and the post operative stability signifi cantly affected by palatal soft tissue scarring. The slow distraction of bone and the histogenic abilities of distraction osteogenesis (DO) have made it an atractive alternative treatment option for the management of maxillary hypoplasia in these patients. This paper presents the treatment results of 15 nongrowing CLP patients with severe maxillary hypoplasia treated by means of intra oral distraction. The mean anterior distraction of the maxillas was 12.7 mm (9-15.0 mm). The long-term cephalometric and clinical evaluation after a minimum of 60 months (mean follow-up 71 months) proved to be stable. The treatment results revealed, that distraction osteogenesis in nongrowing CLP patients with severe maxillary hypoplasia proved to be a predictable and stable option (Tab. 2, Fig. 3, Ref. 26). Text in PDF www.elis.sk. KEY WORDS: distraction osteogenesis (DO), cleft lip and palate (CLP), internal device, maxillary hypoplasia.