Orbital Foraminal Morphometrics in Nonsyndromic Unilateral Coronal Craniosynostosis

Area of Science:

• Craniofacial surgery
• Pediatric ophthalmology
• Medical imaging

Background:

• Nonsyndromic unilateral coronal craniosynostosis (UCS) is a rare congenital disorder causing premature fusion of the coronal suture.
• UCS leads to restricted growth, affecting the calvarium, orbit, and skull base, and is associated with visual abnormalities.

Purpose of the Study:

• To investigate the morphometric differences in orbital foramina between synostotic and nonsynostotic sides in pediatric UCS patients.
• To explore the potential link between orbital foramen dimensions and the high prevalence of visual abnormalities in UCS.

Main Methods:

• Geometric morphometric analysis of 3D CT head scan models from pediatric UCS patients.
• Measurement and comparison of dimensions of orbital structures on synostotic versus nonsynostotic sides.
• Review of medical records to determine the prevalence of ophthalmologic abnormalities.

Main Results:

• Orbits on the synostotic side were significantly narrower (11.3% decrease) and had less volume (21.2% decrease) compared to the nonsynostotic side.
• No significant differences were found in the dimensions (width, circumference, area) of supraorbital, infraorbital, optic, and foramen ovale between the two sides.
• A high prevalence of visual abnormalities (77.8%) was observed, including astigmatism, anisometropic amblyopia, and motor nerve palsies.

Conclusions:

• While UCS affects orbital dimensions, the bony orbital foramina themselves are not significantly distorted or compressed.
• Compression or distortion of neurovascular structures within these foramina is unlikely to be the primary cause of visual abnormalities in UCS.
• Further research is needed to elucidate the role of ocular and neuro-ophthalmologic factors in the visual deficits associated with UCS.