Unilateral maxillary hypoplasia is a characteristic feature of an oblique facial cleft. This three-dimensional shortage of osseous structures and soft tissue becomes more prominent over the years and is difficult to correct. The authors describe a 17-year-old boy born with a unilateral nasomaxillary dysplasia and nasal dysplasia (Tessier type 1, 2, 3) who underwent a hemi-Le Fort III distraction with a rigid external distraction (RED) system. This distraction, in combination with initial peroperative advancement and retained with elastic traction with a facial mask, achieved a substantial horizontal improvement of the hemi-midface; this resulted in a better projection of the left cheek, infra-orbital rim, nasal ala, and improved occlusion. Owing to the underdevelopment of the maxilla and zygoma in all three dimensions, contour deformities remain. Creating several bone segments for multidirectional distraction would jeopardize vascularization of the bone. Good long-term planning is essential in these complicated cases, and more long-term results need to be assessed. The major reconstructive challenge for this complex pathology continues.