Interindividual Variability in Thyroid Cartilage Lamina Width and Its Implications for Personalized Medialization...

Aim: The aim of this study was to analyze anterior and posterior thickness measurements of the thyroid cartilage lamina and to assess their association with age and sex, with a focus on interindividual anatomical variability relevant to personalized medialization thyroplasty. Methods: A retrospective observational study was conducted on 47 patients with unilateral vocal cord paralysis who were candidates for medialization thyroplasty. The thickness of the thyroid cartilage was measured at its anterior and posterior aspects on an axial CT scan at the level of the glottic plane. The Wilcoxon signed-rank test was used to compare anterior and posterior thickness measurements, and a generalized linear mixed model (was fitted to assess the influence of anatomical region, age, and sex on cartilage thickness, with patient as a random effect. Results: The posterior thickness was significantly greater than the anterior thickness (median difference = 1 mm; p < 0.001). No significant differences were found in the magnitude of this difference by gender (p = 0.37) or a significant correlation with age (r = 0.16; p = 0.28). The mixed model confirmed that anatomical region was the only statistically significant fixed effect: the posterior region showed a Risk Ratio of 1.71 (95% CI: 1.26-2.32; p < 0.001) relative to the anterior region, indicating that the posterior thickness was approximately 71% greater than that of the anterior region. The interaction between cartilage thickness, age and gender was not statistically relevant. Discussion: In our sample, the thyroid cartilage had a thicker posterior width in both sexes. These findings underscore the importance of individualized radiological assessment in laryngeal framework surgery and support a personalized approach to implant selection and surgical planning in medialization thyroplasty.