The American Cancer Society estimates that 44,670 new cases of thyroid cancer occurred in 2010 (33,930 in women, and 10,740 in men). Thyroid cancer caused about 1,690 deaths (960 women and 730 men). Thyroid cancer is different from many other adult cancers in that it is commonly diagnosed in younger people. Nearly two of three cases are found in people between the ages of 20 and 55.

Despite these changes in incidence rates, risk of death has remained stable over the past 30 years. It has been at about 0.5 deaths per 100,000 American women and at 0.4 to 0.5 per 100,000 for American men. Indeed, thyroid cancer is one of the most survivable of cancers. More than 97% of patients do very well.

Much of this increase is thought to be the result of the increased medical imaging of the thyroid. It is not so much that there are more thyroid cancers, as that more thyroid cancers are being discovered or diagnosed. Use of CAT scans, MRI scans and thyroid ultrasound has dramatically increased over the past 30 years. These tests can detect very small thyroid nodules that several decades ago would not have been found.

While the experts that I consulted do recommend use of a thyroid collar, none of the experts was especially worried that dental X-rays are a significant cause of thyroid cancer. There is however significant concern that radiation from other forms of medical testing may be causing some thyroid cancers. CT scanning is the medical procedure that concerns experts the most. It uses higher levels of radiation than conventional X-rays and much higher levels of radiation than are used in dental X-rays。