X-rays provide the dentist with an important tool that shows the condition of your teeth. As well as your teeth roots, jaw placement and the overall composition of your facial bones. X-rays can help your dentist determine the presence or degree of periodontal (gum) disease, abscesses, cavities and many abnormal growths, such as cysts and tumors. X-rays also show the exact location of impacted tooth. X-rays are normally taken once a year, sometimes more if the dentist wants to review a problem focus area.