除了脑癌，牙科X射线是甲状腺癌 (thyroid cancer)的危险因素。大多数暴露于牙科X射线的患者不会很快发生癌症，这会使他们在使用牙科X射线时得到不该有的安慰。
Dental x‐rays raises risk of meningioma
Dental x-ray is considered low dose. But lots of studies have found evidence that suggests that using dental x-ray can increase risk of brain cancer – meningioma. A study released in 2012 confirmed that exposure to dental x-ray can increase risk of meningioma.
Researchers found the link after they analyzed data from 1433 patients with intracranial meningioma diagnosed at ages 20 to 79 years who resided in Connecticut, Massachusetts, North Carolina, California and Texas between May 1, 2006 and April 28 2011.
In this case study, patients with meningioma were more than twice as likely to report having ever had a bitewing dental x ray imaging.
Those who had received bitewing films annually or more often were 40% more likely to develop meningioma among those ages 10 years or younger. Among those ages 10 to 19 years, the risk was raised by 60%. Among those ages 20 to 49 years, the risk was 90% increased and among those ages 40 or older, the risk was elevated by 50%.
Panorex imaging taken at a young age or frequently at ages younger than 10 years, the risk for meningioma was increased by nearly 500%.
In many dental clinics, dentists now use digital x-ray which uses relatively lower dose of x-ray. Still, this lower dose x-ray does not mean to be risk free. Any amount of x-ray can increase the risk of cancer! The worse thing is that dentists know the dose used is lower, which give them an excuse to abuse x-ray, as a result, they use it too often!
In addition to brain cancer, dental x-ray is a risk factor for thyroid cancer. Most patients exposed to dental x-ray will not develop cancer quickly, which can give them a false comfort with use of dental x-ray.
Most dentists do not care about the risk of dental x-ray to patients. In many cases, they force use of dental x-ray. They downplays dental x-ray. Many dental assistants are ill-trained and often take more pictures than needed. This practice not only increases risk of cancer in patients, but also dental assistants themselves.