Hidden bridges of the cranium: anatomical foundations of clinical challenges

Aims: This study aimed to evaluate the frequency, laterality, morphology, and coexistence of clinically relevant cranial bony bridges (interclinoid bridge, caroticoclinoid bridge, pterygospinous bridge and pterygoalar bridge ) in dry human skulls. Methods: Forty adult dry human skulls of unknown age and sex were examined. Only specimens allowing visualization of the sphenoid bone were included. The presence and morphology of the caroticoclinoid foramen (CCF), interclinoid foramen (ICF), pterygospinous bridge, and pterygoalar bridge were assessed. Variants were classified according to completeness, laterality, and associated spicules, and all findings were documented photographically.Results: Examination of 40 skulls identified infrequent sphenoidal bony bridges: one specimen showed bilateral complete caroticoclinoid foramina concomitant with bilateral interclinoid foramina, without spicular components. Unilateral pterygospinous bridging occurred in two skulls on opposite sides, whereas pterygoalar bridges were not observed.Conclusion: Cranial bony bridges represent clinically relevant anatomical variants that warrant careful consideration during diagnostic evaluation, particularly in patients presenting with atypical or unexplained neurological symptoms. Recognition of these variations is essential for preoperative planning, as their presence may increase the risk of neurovascular injury and intraoperative complications. A thorough understanding of the incidence and clinical implications of cranial bony bridges, as demonstrated in our laboratory observations and supported by the existing literature, is therefore critical for optimizing diagnostic accuracy and ensuring safe and effective surgical management.