Multiple external-internal resorptions as late effects of thorium X (224 Ra)

Multiple external-internal resorptions are infrequent and are related to a variety of etiological factors. Thorium X (224Ra) is believed to cause the dental resorptive changes observed in 2 patients who had received a series of injections each containing 8 to 70 muCi of 224Ra 25 years previously.