The Effect of Neurocranial Surgery on Basicranial Morphology in Isolated Sagittal Craniosynostosis

Abstract

Objective Isolated sagittal craniosynostosis produces a scaphocephalic neurocranium associated with abnormal basicranial morphology, providing additional evidence of the developmental relationship of the neurocranium and basicranium. Corrective surgical procedures vary, but the immediate impact of the surgical procedure is restricted to the neurocranium. This study addresses the secondary effects of neurocranial surgery on the cranial base. Design Three-dimensional (3-D) computed tomography (CT) scans were obtained for preoperative (n = 25) and postoperative (n = 12) patients with isolated sagittal synostosis. Landmark data from 14 landmarks on and around the cranial base were collected from 3-D CT reconstructions and analyzed using Euclidean distance matrix analysis. Subsamples of age-matched patients were used to identify basicranial differences in pre- and postoperative patients and to compare postoperative growth patterns identified in longitudinal data with preoperative growth patterns characterized in cross-sectional data. Results Statistically significant differences (p ≤ 0.10) were found in the morphology of the cranial base in preoperative and postoperative patients. The relative positions of the landmarks nasion, right asterion, and left asterion are similar in preoperative and postoperative patients. However, the position of these landmarks relative to the cranial base is different in the two groups, being positioned relatively more anteriorly in postoperative patients. In addition, we found that the cranial base angle, on average, neither increases nor decreases in the first postoperative year. These morphological differences are associated with divergent growth trajectories in the operated and unoperated cranial base. Conclusion Regardless of specific procedure, neurocranial surgery in sagittal synostosis patients affects growth patterns of the cranial base. The lack of change in the postoperative cranial base angle suggests that neurocranial surgery alleviates the occipital rotation and decreased cranial base angle described in the sagittal synostosis basicranium.

Craniofacial Shape Variation in Twist1+/− Mutant Mice

“…In the present case of Twist1 haploinsufficiency, we cannot conclusively determine whether the morphological alterations to the rest of the skull are secondary to the coronal suture abnormality or whether the other areas are also directly affected by the null heterozygous condition. Changes in the calvarium are known to have effects throughout the entire skull; both culturally and postoperatively modified vaults in humans cause subsequent changes in the cranial base (Marsh and Vannier, ; Anton, ; Cheverud et al, ; DeLeon et al, ). This type of basicranial change has also been noted in animal models (Mooney et al, ; Burrows et al, ).…”

Morphological integration of the skull in craniofacial anomalies

“…Our purpose is not to differentiate among operative procedures on the basis of outcome, but rather to determine the generalized effect that the removal of the constraint of the fused sagittal suture has on the integration of cranial base measures. Data from these samples have been previously analysed and reported (11, 24).…”

“…Although the importance of the interaction of soft and hard tissues in development and evolution of the head has long been recognized, the skull has been singled out as a structure worthy of independent analysis. The impact that dysmorphology or deformation of one of the skull regions can have on the others is shown in studies of non‐local effects of 1) culturally motivated cranial deformation cradle boarding (4–6); 2) congenital cranial anomalies in humans and animal models (7–10); 3) analyses of the secondary effects of cranial vault surgery (11–13).…”

Growth‐related shape changes in the fetal craniofacial complex of humans (Homo sapiens) and pigtailed macaques (Macaca nemestrina): A 3D‐CT comparative analysis

“…on 3D‐CT reconstructions and axial slices for each macaque and human skull on a desktop personal computer (PC) running VoxBlast, a 3D measurement and visualization software package (Colburn et al, 1998). Landmarks were modified from Corner and Richtsmeier (1992), and were used by the authors in recent publications (DeLeon et al, 2001; Zumpano et al, 1999).…”