The relationship between the carotid canal and mandibular condyle: an anatomical study with application to surgical approaches to the skull base via the infratemporal fossa

Objectives: To review the relationship of the internal carotid artery, and carotid canal to the mandibular condyle, specifically from an infratemporal fossa approach. Skull base procedures which involve the middle cranial fossa utilize an infratemporal fossa approach either as the primary or adjunct surgical approach often performed with access osteotomies. In these surgeries, injury to the internal carotid artery and carotid canal may occur leading to many vascular complications ranging from internal carotid artery transection and thrombosis to embolism of distal communicating segments. Hence, knowing the relationship of these important structures is of utmost importance for skull base surgeons. In addition, the necessity for this knowledge is critical for clinicians to be able to understand the mechanism by which medial displacement of the mandibular condyle may cause blunt internal carotid artery injury in the evaluation of trauma patients. Identification of these structures and understanding their relationship on imaging may be used in the decision process to perform angiography based imaging. Methods: Twenty dry skulls were utilized for a total of forty sides and the distance between the proximal carotid canal and the medial aspect of the mandibular condyle was measured. Results: The average distance between the mandibular condyle and the carotid canal on right and left sided specimens was 1.03 cm and 1.11 cm, respectively. The length ranged from 0.2 cm to 1.7 cm. No significant differences were found between right and left sides. Conclusion: A clear understanding of the anatomical relationship between the carotid canal and the head of the mandible, an easily identifiable landmark, is important for clinicians and surgeons alike. A substantial distance variability was observed in the samples studied. The understanding of this relationship should help identify patients at risk for ICA injury during surgical approaches and in the trauma setting.