The effects of early Le Fort I osteotomies on craniofacial growth of juvenile Macaca nemestrina monkeys.

Le Fort I osteotomies were performed on three juvenile Macaca nemestrina monkeys with midface deficiencies from prior extraoral traction. The maxillas of these monkeys were moved anteriorly an amount necessary to achieve about 8 mm. of horizontal overjet. Interosseous wires were used to stabilize the segments; the animals were not placed in intermaxillary fixation. Craniofacial growth in the three experimental monkeys and in three control monkeys was monitored for 2 years with serial cephalometric radiographs. Compared to the controls, the maxillas of the experimental animals demonstrated less anterior growth, and this was manifested clinically in anterior dental cross-bite relationships. Histologic examination of the circummaxillary sutural complex revealed normal morphology. It is concluded, therefore, that early Le Fort I osteotomies significantly affect subsequent maxillary growth in monkeys and that this effect probably is due to formation of scar tissue.