What Is an OPG X-Ray? Full Form, Meaning and Uses in Plain English

OPG stands for orthopantomogram, a panoramic Dental X-ray that captures both jaws, all the teeth and the jaw joints in one image. A machine rotates around your head for about fifteen seconds to take it. Dentists use it to check wisdom teeth, unerupted teeth, bone and jaw problems before braces, implants and other treatment. 

If your Dentist has written "OPG" on a referral slip, the term can look more technical than it is. This is a short guide to the name, what the picture shows, and what it is used for. 

OPG Full Form: Orthopantomogram 

The word is built from three roots. Ortho means straight, pan means all, and tomo means slice. An orthopantomogram is, literally, a straight, all-round slice through the jaws. 

The machine that takes it is called an orthopantomograph or a panoramic x-ray machine, and the picture it produces is the orthopantomogram. In everyday conversation, nearly everyone says OPG. 

Outside dentistry, the same three letters can mean something else. In medical research, OPG is also the abbreviation for osteoprotegerin, a protein involved in bone metabolism. If the letters appear on a Dental referral, they mean the panoramic X-ray. 

OPG, OPT, Panoramic X-Ray and Pano: The Same Thing 

You may meet any of these names for the same investigation: 

• OPG: the most common label in India. 

• OPT: orthopantomography, the same word abbreviated differently, common in textbooks. 

• Panoramic X-ray or panoramic radiograph or Panorex: the plain-English name, and the term used in most international literature. 

• Pano or panoral: clinic shorthand. 

If one clinic writes OPG and another writes panoramic X-ray, they are asking for the same picture. 

What Does an OPG Show? 

A single OPG image shows both jaws and every tooth in them, erupted or not, on one wide picture. It also shows the jaw joints near the ears, the floor of the sinuses above the upper back teeth, and the nerve canals of the lower jaw. Large cysts, fractures, and areas of bone loss usually appear on it as well. Details such as early cavities and the thickness of the jawbone do not show on an OPG, which is why other X-rays are sometimes added. A fuller guide to what an OPG shows and where it falls short is available. 

What Is an OPG Used For? 

Dentists use an OPG when they need an overview of the whole mouth. The usual reasons are planning braces or aligners, assessing wisdom teeth, getting a first look before implants or dentures, investigating pain or swelling with no clear cause, checking whether a child's adult teeth are developing normally and screening the jaw after an injury. Hospitals also request one as part of a Dental check before certain treatments, such as radiotherapy to the head and neck. 

How Does an OPG Differ From the Small Films Taken Inside the Mouth? 

Bitewings and periapical films are small and are placed inside the mouth. They show a few teeth in fine detail and are the better choice for finding cavities or looking at a single root. An OPG is taken from outside the mouth and covers everything, but with less fine detail. The two are complementary, and many patients need both. 

How Long Does an OPG Take, and Does It Hurt? 

The machine rotates around your head for about ten to twenty seconds, and the whole visit usually takes a few minutes. It is painless. You bite on a small plastic block, rest your chin on a support and stay still while the arm rotates. Metals such as earrings, nose pins, necklaces and hair clips has to come off first, because it casts shadows on the picture. 

Is an OPG the Same as an X-Ray, a CT Scan or a CBCT? 

An OPG is an X-ray, so it does use radiation. It produces a flat, two-dimensional picture at a low dose. 

A CT scan is a different kind of investigation. A medical CT builds cross-sectional images of the body at a much higher dose. A CBCT, or cone beam CT, is the Dental version: it builds a three-dimensional model of the jaws at a dose that sits between an OPG and a medical CT. Dentists choose between an OPG and a CBCT according to the question being asked, and OPG vs CBCT explains how. 

How Safe Is an OPG? 

A digital OPG delivers about 5 to 25 microsieverts of effective dose, which is roughly one to four days of the natural background radiation everyone receives. It should still be taken only when it will change what your Dentist does. If you are pregnant, tell the clinic before the scan. 

Who Reads the Image? 

Taking the picture and interpreting it are different jobs. At DMD Imaging, every OPG is formally reviewed and reported by a qualified Dental Radiologist, and all findings are reported at no extra charge. Understanding Your OPG Report translates the usual wording of a report into plain English. To book an OPG, contact DMD Imaging.

Frequently Asked Questions

• What is the full form of OPG in a Dental X-ray?

  OPG stands for orthopantomogram, a panoramic X-ray of both jaws, all the teeth and the jaw joints.

• Is OPG an X-ray?

  Yes. An OPG is a panoramic Dental X-ray taken by a machine that rotates around the head, producing one flat image at a low dose.

• What does an OPG show?

  Both jaws, every tooth including unerupted ones, the jaw joints, the lower sinuses and the nerve canal of the lower jaw. It shows large cysts and bone loss but not fine detail such as early cavities.

• Is an OPG the same as a panoramic X-ray?

  Yes. OPG, OPT, panoramic X-ray and panoramic radiograph are different names for the same investigation.

• Does OPG stand for anything else in medicine?

  In research, OPG also stands for osteoprotegerin, a protein linked to bone metabolism. On a Dental referral it always means orthopantomogram.

• Is an OPG painful?

  No. Nothing is placed in the mouth except a plastic bite block, and the machine rotates around you without touching your face.