Abstract
In addition to congenital control, growth disorders of the facial bone have been attributed to other factors such as surgical invasion of the maxilla. For more than thirty years, animal experiments have been conducted in attempts to ascertain the extent of facial bone disorders induced by surgical procedures. The major congenital disorders of our patients have been cleft lip and palate, and most of the contemplated surgery has been for treatment of these disorders. Clinically, we suspected that partial exposure of the vomer bone, which often occurs when the cleft palate is closed, affects facial bone growth postoperatively. We investigated this possibility by resection of the partial mucous-periosteum compound tissue on the vomers of 220 rats. We divided 220 infant Wistar rats (100 g) into two equal groups, A and B. The vomer bone in group A was partially exposed by resecting the right vomerin mucous-periosteum compound tissue (6 mm×3 mm wide) under a flap made on the center of the palate. The flap was then returned to cover the palate bone and restore it to its preoperative condition. In group B, a flap was made the same as that in group A. This flap was then restored as in group A to complete the sham operation. This group was used as control. The skulls of the rats of both groups were removed and dried three months after the operations, and the length and symmetry of the maxilla was measured to determine any abnormality introduced as a result of surgery. Statistically, the maxilla of the rats in group A were significantly inclined in the direction of the side upon which we had operated, while the maxilla of the rats in group B were symmetrical. Forward growth of the maxilla of group A rats was significantly less than that of group B.
