Dental X-Ray (OPG)

What is an OPG?

OPG is short for orthopantomogram, which is an x-ray picture showing all the teeth on a single film. The OPG is quite different to the small films taken by dentists which provide a detailed close-up look at problems with individual teeth. 

An OPG film may be requested by your dentist for a wide variety of reasons, but is most commonly used for planning orthodontic treatment. OPG’s can also show other problems in the jawbone (mandible) or in the temporomandibular joints (TMJ’s) which connect the jawbone to the head. 


What is a Cephalometrogram? 

A lateral cephalometrogram (or ‘lat ceph’ for short) is a side-view x-ray of the face showing the bones and facial contours in profile on a single film. Cephalometrogram films are used in the diagnosis of orthodontic problems and for planning treatment. 


What happens during Dental X- Rays? 

OPG and cephalometrogram films are taken with an x-ray machine designed just for these two examinations. First, the technician will ask you to stand with your head against the machine, and will adjust the height until it is comfortable. 

For an OPG film you will be asked to bite gently on a peg which fits between the front teeth. For each patient this peg is covered with a disposable plastic sleeve so there is no risk of infection. As the picture is taken, the machine rotates slowly around you and it is essential to keep as still as possible. Even the slightest movement can blur the image, requiring the x-ray to be repeated. 

For the cephalometrogram, a pair of coneshaped plastic supports are gently positioned in each ear, rather like a pair of headphones. This aligns both ears to ensure that an exact side view of the face is obtained. 


How long do Dental X-Rays take? 

An average examination takes around 15 minutes to complete. The pictures are then checked by the radiologist who writes a brief report. Your own dentist will later assess details of the dentition.


How do I prepare for Dental X- Rays?

No preparation is required.


Are there any after effects of Dental X- Rays? 

The OPG and cephalometrogram are basic diagnostic methods in modern dentistry and orthodontics. The benefits from these x-rays far outweigh the theoretical small risk of side effects. The amount of radiation required is extremely small with the modern equipment used in our practices. 


How do I get my results? 

Your doctor will receive a written report on your test as soon as is practicable. 

It is very important that you discuss the results with the doctor whom referred you so that they can explain what the results mean for you. 


This information is credited to Inside Radiology, Royal Australian and New Zealand College of Radiology (RANZCR). 


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