Characterization of the Bony Matrix of the Otic Capsule in Human Fetuses by EPMA

The fetal ossification pattern of the human otic capsule is studied using electron probe microanalysis (EPMA). By scanning electron microscopy the differences in geometry and orientation in the specimen, as well as the non-uniform matrix density and thickness, are clearly observed. The "peak-to-background" method was applied in order to compensate for the variation in density and surface topography. Standards were used as reference samples and the reproducibility, precision and accuracy of the analysis were studied for the three layers composing the otic capsule.