Long-term effects of rigid fixation on the growing craniomaxillofacial skeleton.

Fixation of craniomaxillofacial bones with plates and screws is becoming an increasingly popular method of managing patients with maxillofacial fractures, congenital anomalies, and skeletal defects after tumor extirpation. The effects of rigid fixation on growth, however, are not well defined and remain controversial. This experimental work was designed to evaluate the effects of rigid fixation on the growing craniomaxillofacial skeleton. Eight 2-month-old beagle dogs were divided into two groups. Cephalometric analysis and computed tomography were obtained preoperatively to establish a baseline of the craniomaxillofacial skeleton. Rigid fixation using plates and screws was applied across the intact coronal and nasofrontal sutures. The contralateral side served as the control. The periosteum was elevated over the contralateral suture and replaced without any surgical intervention. The animals were killed one year after application of rigid fixation, when they had achieved full and mature skeletal growth. The skulls were evaluated both grossly and cephalometrically. There was bony growth over some of the plates, as well as sclerosis of the plated suture lines. Cephalometric analysis demonstrated consistent asymmetry between the plated and nonplated sides, with deviation of the midline toward the plated side in all of the animals. Although further studies are necessary to clarify this issue fully, we conclude from our study that rigid fixation during skeletal development can potentially alter the growth patterns of the craniomaxillofacial skeleton and should be used with caution.