Developmental changes in hypoglossal canal morphometry and its anatomical relationships: a CT study in 180 pediatric patients.

PURPOSE: To evaluate age- and sex-related changes in hypoglossal canal (HC) morphology and its anatomical relationships with skull base landmarks in a pediatric population using computed tomography (CT). MATERIALS AND METHODS: Children aged 0-17 years who underwent cranial CT were included. Each age group comprised five males and five females. The HC diameters were measured on transverse and multiplanar reformatted images at the midpoint, as well as at the intracranial and extracranial openings. The HC length was also recorded. The distances between the HC and the clivus cortex, the occipital condyle (OC) and the posterior condylar canal (if present) were evaluated. Inter-observer and intra-observer agreement was assessed in 20% of the sample (36 patients, 72 HCs). RESULTS: A total of 360 HCs from 180 pediatric patients were analyzed using linear mixed-effects models accounting for the non-independence of bilateral measurements. Twelve of 13 measurements demonstrated significant age-related enlargement (FDR q < 0.05), most pronounced in distances from the HC to the clivus and OC, a pattern confirmed by monotonic trend analysis. Age-group comparisons showed a significant omnibus effect for 12 of 13 measurements, with the most pronounced differences observed between the youngest and oldest groups. Twelve of 13 measurements also differed significantly by sex, with consistently smaller dimensions in females (regression coefficients ranging from - 0.30 to -0.93 mm, all FDR q < 0.05) and no significant age-by-sex interaction. In contrast, no measurement showed a significant right-left difference or age-by-side interaction. CONCLUSION: This CT-based study provides detailed morphometric data on the pediatric HC and its anatomical relationships. The findings demonstrate age- and sex-related developmental changes while preserving bilateral symmetry and may serve as a reference for pediatric skull base imaging and surgery.