The Osseous Anatomy of Unilateral Coronal Synostosis

Abstract

While cranial and orbital osseous manipulation has become popular for infants with unilateral coronal synostosis (UCS), critical evaluation of the efficacy of these operations with respect to the configuration and growth of the skull, brain, and globes is lacking. The absence of a means for quantitative description of the unaltered original deformity precludes effective postoperative study. Nonetheless, detailed images of cranio-orbital hard and soft tissues are available from CT scanning. The high geometric fidelity of CT scans makes these images preferable for quantitation of these deformities. Our study was undertaken to: (a) qualitatively describe the cranial base anomalies associated with UCS; (b) define a set of quantitative measurements which are useful in evaluation of the skull in patients with UCS; (c) identify sources of error in selected linear and angular measurements on axial, paraxial reformated, and 3-D surface reformated CT images; and (d) use these measurements to study a series of eight patients with UCS, before and for up to 1 year after surgery (Figs. 1, 2).