Quantitative Assessment of Supraorbital Osseous Bar Stability and Symmetry after Frontal Orbital Advancement for Unilateral Coronal Craniosynostosis

Frontal-orbital advancement is the accepted surgical treatment for correcting the cranial deformity associated with premature fusion of one of the coronal cranial sutures. Removal and reshaping of the brow and lower forehead bone is performed to correct ipsilateral frontal flattening and parietal bulging, recession of the supraorbital rim, and contralateral forehead bossing. In addition to the functional aspects of the treatment, bilateral symmetry is one desirable outcome that is difficult to achieve because of the recessive movement and shape changes of the supraorbital rim that continue to occur over a prolonged period of time after the operation. Surgeons often over correct the deformity to compensate for post-operative recession and achieve better symmetry at skeletal maturity. This study is to quantitatively evaluate the stability and symmetry of the repaired supraorbital rim after the craniofacial reshaping procedures in patients with unilateral fusion of the coronal suture. CT scans taken at pre-op, post-op and two years later were available for digital analysis. Quantitative methods are developed to calculate the magnitude of advancement, magnitude of movement in the two years period following the surgery, and supraorbital bilateral symmetry at all three time points. Quantitative statistics of the post-op supraorbital rim stability will provide clinically relevant information for surgical planning that could optimize surgical technique.