Influence of Aging and Menopause in the Origin of the Superior Semicircular Canal Dehiscence

Abstract

OBJECTIVE: Determine if aging and menopause, known to be associated with bone resortion, also are associated with superior semicircular canal dehiscence. DESIGN: Observational study. SETTING: Study conducted in 3 tertiary Spanish hospitals. PATIENTS: Nonselected consecutive patients of all ages. INTERVENTIONS: Thin-section multi-detector row computed tomographic scan of the temporal bones. MAIN OUTCOME MEASURE: The minimum thickness of the bone covering the roof of the superior semicircular canal (SSC) measured in each temporal bone. The outcome was studied both as a continuous and as a dichotomous variable: thin (<0.6 mm) and normal (≥ 0.6 mm). RESULTS: Five hundred eighty-two ears of 312 patients were included in the study. Fifty-five percent of the sample were women. Patient's age ranged from 2 to 88 years. A 40-year age difference between ears was associated with a decreased thickness of bone covering the SSC of 0.10 mm, which is 10% of the average thickness of such bone. The thickness of the bone overlying the SSC of subjects younger than 45 years was an average of 1.14 mm (SD, 0.52 mm), whereas that of the subjects older than 45 years was equal to 1.02 mm (SD, 0.45 mm; p = 0.006). The percentage of ears with thin bone coverage of SSC was 7.1% in subjects younger than 45 years and 13.8% in those older than 45 years (p = 0.013). CONCLUSION: Our data support the hypothesis that there is a slight osteopenia of the roof of the superior semicircular canal associated with aging, and this effect seems to be more pronounced in menopausal women.