The American Dental Association has put forth a list of standards on dental x-rays, and the Canadian Dental Association has since adopted these standards as well. According to these standards, panoramic x-rays should be taken roughly every 5-6 years, and more frequently in cases where abnormalities are found. The first of these panoramic x-rays are taken at approximately ages 6, 12 and 18. These are critical stages of tooth and jaw development and a panoramic x-ray can help to assess a patient for early interceptive orthodontics (age 6), orthodontic treatment (age 12), and for wisdom tooth assessment/extractions (age 18). After a person reaches adulthood, a panoramic x-ray is taken every 5-6 years to monitor bone level (assessing for gum disease), as well as monitoring for any potential developments of cysts or unusual growths.
Individual x-rays only show distinct portions of the teeth and jaw. To show all the teeth one would need up to 18 individual x-rays (our digital panoramic machine uses the same radiation as approximately 2 conventional x-rays, and costs less than 18 individual x-rays). This many x-rays show the teeth and bone level around the teeth fairly well, but can be hard to see the complete picture as it is like putting together a puzzle. Additionally, these x-rays do not show the entire jaw, the joints for the jaw, or a complete picture of the sinus cavities. These areas are susceptible to various defects and abnormalities, and can be of extreme importance for your continued dental care. The bottom jaw bone is also a common place to find metastatic cancer (cancer that has spread from another area). Without panoramic x-rays, these concerns can often be missed. And missing them can have serious implications on appropriate timely treatment.
You can view some of these abnormal findings on our x-ray pathology page to learn more: http://www.myfamilydentist.ca/services/cleaning-and-prevention/oral-cancer-screening/x-ray-pathology/