It is important for the dentist to have a good knowledge of the 3-dimensional anatomy of the mouth, teeth and jaws in order to interpret X-rays correctly.
Problems with the X-ray film, the developing process or with the angulation and contrast of the X-ray can all make interpretation more difficult.Your dentist is trained for such circumstances, but occasionally different angles or repeat X-rays are necessary to confirm or rule out something, that looks a little out of the ordinary.
Here are a couple of examples of when things aren’t quite as they seem...
It may look like decay in a tooth
when it is really:
- Old white fillings. Nowadays materials contain particles to prevent this confusion, but once upon a time white fillings didn't have them added, so teeth looked normal in the mouth but as if they had big chunks of tooth missing on the X-ray. Checking the corresponding area carefully on the tooth is all a dentist needs to do to solve this mystery.
- Cervical burnout. This is the term given to a particular appearance on X-rays to describe the area where the tooth transitions from enamel on the top of the tooth, to the cementum of the root. This change in density of the tooth is sometimes very pronounced and can look like decay is occurring in-between the teeth. Checking in the mouth and seeing the same appearance on multiple teeth can help determine if this is just normal anatomy.
Superimposition of other normal anatomy can also cause difficulty in reading X-rays. For example:
- Very crowded teeth or teeth that are out of position may prevent you from seeing accurately what is going on in-between the teeth.
- The mental nerve opening, if it lies very close to your lower premolar roots can sometimes look like and be mistaken for an abscess, or area of infection.
- The inferior dental (ID) nerve can sometimes appear to be very close to the roots of your wisdom teeth, when in reality it's lying more on the inside of the jaw bone. The article on assessing wisdom teeth discusses in more detail how we tell if this is the case!