Abstract
<title>Abstract</title> <p>Purpose The purpose of this study is to determine the frequency of coexistence of greater horn of hyoid bone (GHHB) elongation and twisted carotid bifurcation (TCB) and to hypothesize a possible developmental mechanism underlying this association. Methods One part of the study is monocentric and retrospective: we selected consecutive patients over a 4-year period in whom carotid entrapment by an elongated GHHB was identified. The second part consists of a structured electronic literature search of published case reports. Results In total, 24 patients were included. Cases with a normal carotid bifurcation (Group 1) numbered 10 (41.7%), while those with TCB (Group 2) numbered 14 (58.3%). In all patients of Group 2 the TCB was exclusively right-sided (100%), and GHHB elongation was either right-sided or bilateral. In contrast, in Group 1 GHHB elongation occurred on the right, bilaterally, or on the left. Our findings establish a clear regularity: when TCB and GHHB elongation coexist, the TCB is invariably right-sided and the elongation is right-sided or bilateral. This pattern does not apply when GHHB elongation occurs against a background of normal carotid bifurcation. Conclusion We propose that the most plausible explanation is a shared developmental disturbance of the third pharyngeal arch field, which can simultaneously produce GHHB elongation and excessive lateral migration of the external carotid artery, resulting in TCB. Right-sided predominance is consistent with the normal asymmetry of aortic arch remodeling. This hypothesis remains speculative in the absence of direct embryological series, yet it coherently integrates the clinical regularity we observed.</p>