The effect of total maxillary advancement on facial growth

The effect of total maxillary advancement on the growing skull was examined in 25 pigs, subjected to facial operations of varied severity at the age of 5 weeks (elevation of periosteum, simple osteotomy, and osteotomy immobilized by wire fixation, with or without bone grafts) and in controls. When the animals were killed 8 months later, the body weight had increased tenfold and the skull size had doubled. In 5 pigs whose maxillae were advanced 10 mm by bone grafts, the relative increase in length was not maintained. The overall skull length showed no difference from the control measurements. The extent of the growth in the area adjacent to the osteotomy was less than in the controls, but the same as in pigs subjected to periosteal elevation only. Scattered areas of bone damage were seen with no consistent pattern. Incision of the periosteum over the frontal bone decreased the local blood supply, increased the adherence of the periosteum to the bone, and affected bone growth locally.