A comparative study of roentgenologic signs and pathological changes in experimental subacute fluorosis in rabbits

Summary

A comparative study of the roentgenologic signs and pathological changes in experimental subacute fluorosis was carried out. The plain X-ray films, taken at the end of the first and the second months, revealed that the long bones of the extremities, especially in the anterior limbs, had localized osteoproliferation in the cortex, prominence of the cortex, unevenly thickening of the cortex. Pathological examinations demonstrated osteoporosis of different degree in the cortex of the same areas. In cross section the typical specimens appeared porous and spongy. Microscopically, the haversian system was found to be distorted, the lumina of the canals were irregularly dilated, and the number of micrangia was increased. In the inner wall of the canals the osteoblasts were densely crowded and linearly arranged, and the osteoclasts depressed. Under the fluorescent microscope, the growing skeleton of the experimental animals, labelled by tetracycline, showed disappearance of the endogenous growth zone and the double fluorescence lines. Other changes, such as external shifting, winding, thickening as well as irregular pattern, could also be observed. The formation of new bone was irregular. All these suggested that the long bones of the domestic rabbit were affected by fluorine in growth and development.