A HISTOLOGICAL AND DEVELOPMENTAL STUDY OF THE TEMPORAL BONE IN COMPARISON WITH THE FEMUR, PARIETAL BONE AND COSTAL BONE

Abstract

Pneumatization of the temporal bone is developed by apposition and resorption of the bone. These two processes are most remarkable in the last stage of the fetal life and postnataly these pro-cesses gradually decrease until adolescence. After adolescence these processes reach to their minimum activity, so that the, bone structure keep its status.As the age advances, only absorbing activity becomes active and in the temporal bone of the aged person very significant resorption of the bone walls of the air cells was found. This process results in well-developed air cells, which coresponds to osteoporosis in the general bone tissues.But in the temporal bone the resorption process in the preadolescence and postadolescence period is not same. The resorption in the fomer is lacunar and the giant cells were found in the area where bone resorption is suspected, but in the latter there were found now formation of the capillary blood vessels and connective tissues in stead of the giant cells.These appearances of the temporal bones in the old-aged may be reconized as the characteristics of the temoral bone.In the other bones apposition of the bone tissue is active in the preadolescence period as that of the temporal bone, but the absorption is not so remarkable. It is beyond doubt that in the postnatal life resorption process in these bones is present, because the osteoporotic appearance is found in them, namely wide marrow spaces and dilated Haver's canal, but the giant cells or other findings related to resorption could not be demonstrated.From the comparison of the structure of the temporal bone with that of the other bones, the author has concluded that the well-developed temporal bones appear in the cases with the thin lamellae and the wide marrow spaces in the parietal bone and femur, and that the temporal bones with under-developed pneumatization appear in the cases with thick lamellae and narrow marrow spaces in the parietal bone and femur.