Maxillary distraction osteogenesis: A two-dimensional mathematical model

Patients with cleft lip and palate with severe maxillary retrusion usually have a mandible with anterior-superior autorotation and subsequent overclos ure and loss of the vertical facial dimension. Maxillary distraction osteog enesis can correct the sagittal maxillomandibular relationship and should s imultaneously reestablish vertical dimension through maxillary vertical hei ght increase and clockwise rotation of the mandible to restore facial balan ce. We present a two-dimensional mathematical model in the sagittal plane, which reestablishes sagittal and vertical skeletal deficiencies and proper occlusal alignment for planning maxillary advancement with distraction oste ogenesis in patients with cleft lip and palate. The model is illustrated in a case of a 13-year-old boy with a complete bilateral cleft lip and palate and severe maxillary retrusion. The two-dimensional mathematical model des cribed in this article allows the surgeon and orthodontist to calculate in a simple and accurate way the ideal distraction vector to advance the maxil la to its desired position.