Hypothyroidism and Mandibular Cortical Alterations Evaluated on Panoramic Radiography: A Cross-Sectional Study in Women.

BACKGROUND/

OBJECTIVES

Thyroid hormone deficiency may impair bone metabolism, but its mandibular impact remains uncertain. We aimed to compare the prevalence of altered Mandibular Cortical Index (MCI; C2-C3) and Panoramic Mandibular Index (PMI) on digital panoramic radiographs in adult women with primary hypothyroidism versus euthyroid controls, considering age and key clinical covariates. To our knowledge, this is the first study out of Spain addressing this question.

METHODS

This is a cross-sectional study (September 2021-June 2024) of 179 white women recruited at a university clinic. Cases were on L-thyroxine for ≥6 months, with TSH > 4.5 mIU/L and normal FT4; controls were euthyroid and untreated. Demographics, reproductive history, and BMI were recorded. Panoramic radiographs (Ratograph EVO 3D; 72 kV, 6 mA, 14.4 s) were analysed; MCI was graded (Klemetti C1-C3) distal to the mental foramen; PMI and mandibular cortical width (MCW) were measured bilaterally.

RESULTS

Women with hypothyroidism showed higher BMI and a greater number of years since menopause; age was slightly higher, but the difference was not significant. MCI distribution did not differ between groups (C3 and C2-C3, both p > 0.45). PMI (left/right) was similar (p = 0.253/0.160). Left MCW was higher in hypothyroidism in a crude analysis (4.86 ± 0.98 vs. 4.46 ± 0.94 mm; p = 0.039), but lost significance after age adjustment (adjusted p = 0.191); right MCW showed no differences. Total tooth loss tended to be higher (p = 0.055) without conclusive evidence.

CONCLUSIONS

In this cohort, primary hypothyroidism was not associated with a differential mandibular cortical pattern by MCI or PMI; the crude MCW difference was explained by age. These Spain-based data refine heterogeneous prior findings and indicate that, in women treated for hypothyroidism, mandibular cortical metrics largely resemble those of their euthyroid peers. Longitudinal and multicentre studies are warranted to clarify trajectories and enhance generalisability.