Effects of unilateral premature fusion of the zygomaxillary suture on the growth of nasomaxillary complex.

Unilateral premature fusion of the zygomaxillary suture was produced in 2-week-old guinea pigs by immobilization with methyl-cyanoacrylate adhesive. The effects of sutural fusion on the growth of the nasomaxillary complex were evaluated by radiographic cephalometry with implants, and histologic assessment. The immobilization successfully constrained the anteroinferior displacement of the maxilla and zygomatic bone on the fused side. Compensatory responsive remodeling at adjacent sutures and in certain regions of the nasomaxillary complex was observed. Developmental asymmetry was found when the fused side was compared with the nonfused side. No gross anatomic asymmetry of the facial complex as a whole, however, was detected. Adaptive compensation involving periosteal bone deposition occurred at the junction of the lower maxillary process and the maxilla proper on the fused side. This, together with periosteal bone resorption in corresponding areas on the nonfused side served to offset any developmental asymmetry that might have occurred, thus leading to a compensatory preclusion of gross anatomic asymmetry.