TEMPORAL BONE FINDINGS IN TRISOMY-18 AND TRISOMY-21 SYNDROMES

The temporal bones from fetuses with known autosomal trisomy syndromes were examined histopathologically after spontaneous or induced aborti ons. Fetal ages dated from the 17th to the 24th week of pregnancy. In all, 17 temporal bones from nine fetuses were studied and included sev en cases of Down's syndrome and two of Edwards' syndrome. Temporal bon es from fetuses with Down's syndrome had more abnormalities of the ext ernal and middle ears than of the inner ear. The bones from the fetuse s with Edwards' syndrome showed abnormalities of the external or middl e ear and retarded development of the inner ear (failed ossification o f the otic capsule and unformed organ of Corti).