Evaluation of the Foramen of Civinini and Foramen of Hyrtl in the Human Skull Base: An Osteological Study

Objective: The infratemporal region of the skull base is traversed by critical neurovascular structures, and anatomical variations such as ossified cranial base ligaments, which can pose significant clinical challenges. The foramen of Civinini and Hyrtl, formed by ossification of the pterygospinous and pterygoalar ligaments respectively, are infrequent but surgically relevant entities. This study aims to investigate the anatomical variations in the infratemporal region, with a focus on the ossified ligaments and their clinical implications.
Methods: This osteological study was conducted on 134 adult dry human skulls of unknown age and sex. Each skull was examined bilaterally for the presence of the foramen of Civinini and the foramen of Hyrtl. Parameters analyzed included presence or absence, laterality, completeness of ossification, and their anatomical relationship to the foramen ovale. Notable morphological variations were documented photographically.
Results: The foramen of Civinini was observed in 9 skulls (6.7%), predominantly unilaterally (78%), with complete ossification in 7 cases. The foramen of Hyrtl was identified in 3 skulls (2.2%), all of which were unilateral. Co-existence of both foramina was noted in a single skull, where the foramen of Hyrtl appeared fused with the foramen of Civinini. Comparative analysis using Fisher’s exact test showed no statistically significant differences between the two foramina in terms of laterality or ossification pattern.
Conclusion: Although uncommon, the foramina of Civinini and Hyrtl represent important anatomical variations with potential implications for neurosurgical and maxillofacial procedures. Their presence may hinder access during percutaneous interventions and contribute to unexpected anesthetic or neural complications. Awareness of these variants is essential in surgical planning and radiological interpretation.