When getting X-rays, there are usually two types involved, intraoral and extraoral. When a digital X-ray needs to be taken inside the mouth, those are referred to as intraoral X-rays. Digital X-rays that are taken outside of the mouth (the most common) are referred to as extraoral X-rays.
When X-rays are taken, they allow dental professionals to see a high level of detail not only of the teeth but the roots, jaw, and tissues surrounding the teeth. This means they can get a head start on anything that might be “brewing” in order to stop the progress or reverse the issue. Sometimes, once issues are finally noticed on the surface for patients to go see the dentist, it’s already to the point where it needs more treatment. In some cases, it’s too late to fix the tooth and more drastic measures have to be taken.