The panoramic x-ray is an x-ray of the entire jaw unraveled and flattened out. It is technically a tomogram. A tomogram is a moving x-ray. The image from a tomogram can focus in on special areas. In this case it focuses on the entire upper and lower jaw. It’s important to do a panoramic x-ray in early childhood (around 10 years old) and at about 16 years old and then every 5 years thereafter. This is because the jaws can develop many types of lesions that can be identified on an x-ray of this type.
Some people worry about getting too much radiation. The amount of radiation from a panoramic is about 1,000 millirads. It takes a minimum of 1,000,000 millirads to cause cancer. So a patient who got a panoramic x-ray every 5 years for their entire life if they lived to 100 years old would only get 20,000 millirads. In other words they could get 980 more panoramic x-rays before the radiation would be a problem.
Even though x-rays are very safe we follow strict safety protocols and only get x-rays as necessary.