Experimental effects of bone plating in infancy on craniomaxillofacial skeletal growth

The potential effects of mini- and microfixation on craniofacial development was investigated in an animal model. Twenty-four rabbits had amalgam markers placed bilaterally at the lambdoid, coronal, and frontonasal sutures at 28 days of age. In group 1, plating was not done and served as controls. In groups 2 to 4, single 2- and 4-hole microplates and 4-hole miniplates were fixed across the left coronal suture. The right suture was not plated. After 6 months, intermarker distances and craniofacial angles were measured radiographically. Coronal sutures underneath the plates were also histologically evaluated. Plating across the coronal suture resulted in local anteroposterior constriction of marker distances that did not differ with the type of fixation used. More distant markers, however, were increased in all specimens as a compensation and, as a result, the cranionasal length of all groups were similar. No change in craniofacial angles was observed from that of the controls. Sutural morphology on the side of fixation was altered with decreased widths, cellular numbers, and bone deposition. These experimental results demonstrate that early plate application in a normal calvarium results in local growth restriction that can be overcome by regional bone growth compensation.