Variations in the spatial relationship between the hyoid bone and the carotid arteries and their clinical significance.

BACKGROUND: The topography between the common carotid artery (CA), internal CA, and external CA (ECA) with the greater horn of the hyoid bone (GHHB) is of particular importance for anatomists, radiologists and neck surgeons. AIM: To investigate these topographical relationships emphasizing anatomical classification, sexual dimorphism, and clinical significance. METHODS: A retrospective study was performed on 224 computed tomography angiographies from a cohort comprising 161 male and 63 female patients, with a mean age of 63.2 years. Multiplanar and three-dimensional reconstructions were executed utilizing Horos software. The spatial relationships between the CA and hyoid bone were categorized based on the 12-type classification system delineated by Manta et al in 2023. The data were subsequently stratified by sex and laterality. RESULTS: Type 0 (no arterial contact with the GHHB) was the most common configuration (46.9%), followed by type VI (ECA lateral to GHHB, 23.9%) and type VIII (internal CA and ECA lateral to GHHB, 13.2%). Bilateral symmetry was present in 54.02% of cases, mainly in males. Statistically significant sex-based differences were found (P = 0.012), while laterality was not significant (P = 0.779). CONCLUSION: Carotid-hyoid topography displays significant anatomical variation with clinically essential patterns. Non-null variants, such as types VI and VIII, may increase the risk of dynamic carotid compression, especially in younger patients with cryptogenic cerebrovascular symptoms. Recognizing these variants during preoperative imaging is crucial to minimize surgical risk and inform patient care.