Osteoporosis--an early radiographic sign of endemic fluorosis.

Radiological investigation of skeletal fluorosis was carried out among the inhabitants from two areas where the fluoride content of water was high, using both conventional radiography and radiographic measurements of bone mineral content (BMC). Of 139 cases in the first group, 68 presented bone abnormalities while 21 of 54 cases in the second group showed a similar change. Four essential types of bony lesion were classified. Osteoporosis, especially in the long bones, was the earliest change to be observed. The results of measurements at the distal end of the ulna indicated the presence of a low BMC even among inhabitants with a good nutritional status. It is concluded that osteoporosis towards the ends of long bones is an early radiographic sign of endemic fluorosis especially in an individual under the age of 40 years.