Use of Distraction Osteogenesis to Change Endocranial Morphology in Unilateral Coronal Craniosynostosis Patients

Background: The endocranial morphology of the skull base is an important factor in determining craniofacial asymmetry. Moreover, although the patency of cranial suture would be the first determining factor, unicoronal, unilambdoid synostosis and deformational plagiocephaly can also be differentiated by means of axis angulation of anterior and posterior cranial fossa. These findings indicate the importance of endocranial morphology in craniofacial asymmetry. The authors hypothesized that distraction of the skull base might cause stress on the skull base that could modify skull base angulation deformities. Methods: This study compared the distraction technique with traditional bone repositioning techniques for remodeling skull base axis deformities in synostotic plagiocephaly patients. The study recruited 19 unicoronal craniosynostotic patients, of whom seven underwent distraction treatment and 12 underwent traditional bone graft treatment. Results: The authors found that both approaches resulted in successful outcomes in terms of exocranial morphology correction, but that the distraction technique may offer advantages over traditional methods. Moreover, the authors found that distraction did modify the skull base angulation. Distraction created more changes in the endocranial morphology. The average correction of skull base angulation with distraction was from 164.6 to 174.3 degrees, whereas the correction for the traditional technique was from 165.2 to 166.2 degrees. The amount of change in skull base axis was statistically significant according to the Mann-Whitney test (p < 0.001), but the change in cranial index of asymmetry was not (p = 0.363). Conclusion: The skull base axis in synostotic plagiocephaly, which is composed of the anterior and posterior cranial fossa, underwent greater correction using the distraction method. (Plast. Reconstr. Surg. 126: 995, 2010.)