Roentgen stereophotogrammetric analysis of restricted periods of neurocranial suture immobilization in rabbits.

The effect of temporary fusion of sutures on craniofacial growth was studied biometrically in 4-week-old male New Zealand White rabbits. Tantalum bone markers were implanted in the cranial vault, and the coronal suture immobilized with isobutyl-2-cyanoacrylate adhesive. Linear craniectomy was performed after 2 or 6 weeks of sutural growth restriction (four animals in each group). The animals were followed for approximately 17 weeks. Early craniectomy resulted in greatly increased coronal suture bone separation (175% of control growth rates in peers and 125% of maximal control rates). Growth after late craniectomy showed an age-dependent lower rate, but still the overshoot markedly surpassed controls (210% of control rates in peers and 65% of maximal control growth rates). Overall, both exhibited overcompensation in coronal suture growth. A rapid compensation of adjacent sutures to temporary growth restriction and a tendency toward spontaneous correction following release of growth inhibition were demonstrated. Thus, the total anteroposterior growth of the combined frontonasal and coronal sutures nearly equaled that of control animals. Following linear craniectomy, volumetric calvarial expansion increased considerably in both early and late groups, due to compensatory coronal suture growth, but probably due also to spatial bone rearrangements. Based upon the findings, the length of the suture immobilization period seems critical to longitudinal and volumetric growth as well as to subsequent compensatory activity after surgical correction.