Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones

Previous studies suggest that semicircular canal dehiscences (SCDs) have a developmental origin. We hypothesized that if SCDs originate during development, incidence of radiographic SCDs in young children will be higher than in adults. Thirty-four temporal bone HRCTs of children younger than 2 years and 40 temporal bone HRCTs of patients older than 18 years were reformatted and re-evaluated for presence of SCD or canal thinning. Results were compared with indications for HRCT and clinical information. SCDs were detected in 27.3% of children younger than 2 years of age (superior, 13.8%; posterior, 20%) and in 3% of adults (P < 0.004). Of children with one radiographic dehiscence, 55.6% had multiple and 44% had bilateral SCDs on HRCT. No lateral canal SCDs were present. Thinning of bone overlying the semicircular canals was found in 44% of children younger than 2 years and 2.5% of adults (P < 0.0001). SCDs are more common on HRCTs of very young children. This supports the hypothesis that SCDs originate from discontinuation of bone deposition/maturation. However, SCDs on imaging do not necessarily correlate with canal dehiscence syndrome and should therefore be interpreted carefully. (orig.)