Age-dependent differences in hyoid bone position and shape in thyroglossal duct cyst: a three-dimensional computed tomography case–control study

Abstract Purpose The thyroglossal duct cyst (TGDC) is closely related to the hyoid bone, whose central segment is resected in the Sistrunk procedure, yet hyoid morphology in TGDC has only been examined two-dimensionally in pre-school children. This first age-stratified three-dimensional CT (3D-CT) study aimed to determine whether hyoid size, shape and position differ between TGDC patients and controls and whether this depends on age. Methods Neck CT scans of 30 patients with TGDC and 30 controls frequency-matched by age stratum (0–18, 19–50 and ≥ 51 years) were reconstructed in 3D, and 11 size, shape and positional parameters were measured. Logistic regression and ROC analyses were performed in adults. Results TGDC patients had a lower right greater cornu height (p = 0.031), a greater hyoid–vertebral distance (p = 0.014) and a wider inter-greater-cornu angle (p = 0.048) than controls. In children, no parameter differed between groups; differences were concentrated in the 19–50-year stratum (hyoid–vertebral distance 6.35 ± 1.41 vs 4.68 ± 0.75 mm, p < 0.001; angle p = 0.008; smaller greater cornu heights and body width). In adults, each 1-mm decrease in body width (OR 1.69, 95% CI 1.08–2.65) and each 1-mm increase in hyoid–vertebral distance (OR 1.74, 1.04–2.89) were independently associated with TGDC; AUCs were 0.80 (distance) and 0.77 (angle). Sexual dimorphism present in controls was absent in TGDC. Conclusion Adult, but not paediatric, TGDC is associated with an anteriorly positioned, wider-angled hyoid with lower greater cornua and a narrower body, suggesting age-related perihyoid remodelling relevant to planning the Sistrunk procedure.