[Atypical ossification of anomalous ribs]

Atypical ossifications of anomalous ribs were found in 22 cases of 400.000 fluorograms with rentgenological control (0,005% or 1:18.000). Among them there were 15 cases on the right side, 6--on the left and one bilateral case in the third ribs. The fourth ribs were altered more frequently (12) and the fifth one--less frequently (9). Atypical ossifications were observed only in forked bifurcations of anterior ends which may serve as one of differential diagnostical signs for distinguishing them from other pathological changes.