Panoramic dental X-ray: what it is for, how it works and the dose

A panoramic X-ray (also called a "dental panoramic" or simply a "panoramic") is an X-ray that shows all your teeth, both jaws and the jaw joints in a single image. It is one of the exams dentists ask for most often. This guide explains, in simple words, what it shows, how it works and what is known about the radiation dose, based on the publications cited in the text. It is here to inform you; it does not replace your dentist's advice.

What is a panoramic X-ray for?

It gives an overall view that looking inside the mouth cannot give:

• impacted teeth or teeth that are late to come through, such as wisdom teeth or canines;
• missing teeth or extra teeth;
• the height of the bone around the teeth and under areas without teeth, for example before an implant;
• large cavities, infections at the tip of the roots, old root canal treatments;
• cysts or other unusual images in the jaws;
• in children and teenagers, the dental age and the position of the permanent teeth before orthodontic treatment.

What it shows less well

A panoramic is an "unrolled" image and is a little blurred in places. It is less good at spotting small cavities between the teeth: for these, the dentist instead uses small X-rays taken inside the mouth (bitewings). In children, for example, a review notes that the clinical examination detects more decayed surfaces than the panoramic alone, and that combining a panoramic with bitewings picks up more cavities between the teeth (Timms and Deery, 2021, PubMed). So each X-ray has its own role.

How does the exam work?

1. You are asked to remove any metal objects from your head and neck: earrings, piercings, glasses, removable appliances, hairpins.
2. You stand or sit with your chin on a rest, and you bite on a small mouthpiece to position your teeth correctly.
3. The arm of the machine turns around your head for about fifteen seconds. You need to stay still, with your tongue pressed against the roof of your mouth.
4. The image usually appears on the screen straight away.

The exam does not hurt. If you move, the image can be blurred and may need to be taken again.

What radiation dose?

Dental X-rays are among the exams with the lowest radiation. A review of studies published from 2010 to 2020 finds, on average (Lee and Badal, 2021, PubMed):

So a panoramic is equivalent to a few days of natural background radiation. A dental scan (cone beam, or CBCT) gives a 3D image, which is useful for example before an implant or for a difficult impacted tooth, but its dose varies a lot from one machine and one setting to another; it should be kept for cases where 3D changes the decision (Jacobs, 2011, PubMed).

The rule in radiation protection stays the same: an X-ray only if it is useful, with the lowest possible dose (Benavides et al., 2024, PubMed). If you have a recent X-ray taken elsewhere, bring it with you: it may avoid having to take another one.

Panoramic X-ray and pregnancy

Always tell the dentist if you are pregnant or could be. A historical review concludes that, when properly done, the dose from a dental X-ray is so low that it is unlikely to reach the level at which effects on the fetus appear, and that a necessary dental X-ray can be taken at any time during pregnancy with suitable protection (Flagler et al., 2022, PubMed). If the X-ray is not urgent, the dentist may also choose to postpone it.

What about children?

Children are more sensitive to radiation than adults: a panoramic is only taken if it gives useful information, for example to check that the permanent teeth are present and where they are, or before orthodontic treatment. It is not a "routine" exam to repeat for no reason.

How to read your panoramic X-ray

On the image, the upper jaw is at the top, the lower jaw at the bottom, and your right side is on the left of the image, as if you were facing someone. Light areas are hard tissues (enamel, bone, crowns, metal fillings), dark areas are air and soft tissues. Teeth are identified by a two-digit number: the guide to tooth names and numbers explains how to find your way around. For the interpretation, ask the dentist: some normal features look like abnormalities.

In practice

1. Mention a possible pregnancy before the exam.
2. Remove jewellery, piercings, glasses and removable appliances.
3. Stay still while the machine turns.
4. Keep your X-rays and bring them to your next appointments.
5. Ask the dentist to explain what the image shows.

Frequently asked questions

Is a panoramic X-ray dangerous?

Its dose is low, about the same as a few days of natural background radiation; it is still an X-ray exam, which is only done when it is useful.

How long does a panoramic X-ray take?

Getting set up takes a few minutes and taking the image about fifteen seconds; the image is usually available straight away.

What is the difference between a panoramic X-ray and a dental scan?

A panoramic gives a two-dimensional image of the whole mouth; a dental scan (cone beam) gives a three-dimensional image, more precise for certain cases such as implants, but with a higher dose.

Can I have a panoramic X-ray while pregnant?

A necessary dental X-ray can be taken during pregnancy with suitable protection; always tell the dentist, who may also decide to postpone it if it is not urgent.

Does a panoramic X-ray show all cavities?

No: it shows large cavities well, but small cavities between the teeth less well; for those, the dentist uses small X-rays taken inside the mouth.