Effects of resorbable fixation on craniofacial skeletal growth: modifications in plate size.

On the basis of previous experimental work in young rabbits, modifications in the polymer fixation used (i.e., smaller plate size, change in ratio of polymer components) were studied for potential alleviation of known growth restriction in this model. Ten juvenile rabbits with metallic markers placed at the calvarial sutural junctions were plated across the left coronal suture. At 6 months of age, measurements were taken of both intermarker distances radiographically (growth) and the plates directly. Unlike previous reports, these resorbable plates permitted symmetrical frontal bone development, unaffected growth across the coronal suture, and a histologically normal underlying suture. These changes appear to be the result of elongation of the fixation plate across a growth site. These results indicate that the change in shape of resorbable fixation after initiation of degradation is more important than complete degradation of the material in rapidly growing bone sites.