Panoramic or panorex dental X-rays provide a convenient way to visualize all teeth, jaw structure, and other aspects of oral anatomy using a rotating X-ray beam. However, some sources raise concerns about potential dangers from panoramic dental radiography.
Generally, the radiation exposure from a single panoramic X-ray is considered low compared to medical X-rays of the body, and is only slightly more than that of a dental bitewing. As such, it’s not considered dangerous if the necessary safeguards are followed. If not, the patient may experience thyroid exposure, salivary gland swelling, or some jaw soreness.
But these side effects are uncommon with proper protection using lead shielding collars. Moreover, there are no documented cases of adverse effects from occasional exposure to minimal radiation from panoramic x-rays, like infertility or cancer.
Understanding Panoramic Dental X-Rays
A panoramic X-ray machine rotates slowly around the head capturing the entire upper and lower jaw in a single image called a panorex or panoramic radiograph. This gives a comprehensive two-dimensional overview of the teeth, nerves, sinus cavities, bone structure, and other anatomical details useful for diagnosis and oral surgery planning.
Amount of Radiation Exposure
The radiation exposure from a single panoramic X-ray is considered low compared to medical X-rays of the body. A typical panorex emits only about 10-15 microSieverts (μSv) of radiation. To put this into perspective:
- 10 μSv is approximately equivalent to 3 days of natural background radiation.
- A dental bitewing exam exposes a patient to around 5 μSv.
- A chest X-ray exposes a patient to roughly 100 μSv of radiation.
Potential Dangers and Side Effects
Due to the low exposure, panoramic dental X-rays are not considered dangerous when proper safeguards are followed. Potential risks include:
- Thyroid exposure – This gland is vulnerable to radiation but is protected by lead shielding collars.
- Salivary gland inflammation – Very rare temporary swelling risk.
- Jaw/mouth soreness – Some transient irritation may occur but is uncommon.
There is no evidence that the minimal radiation from an occasional panoramic X-ray causes or contributes to serious conditions like cancer or infertility.
Precautions Dentists Take to Prioritize Safety
To minimize any potential risks, dentists observe strict protocols including:
- Limiting frequency – Panorex taken only every 3-5 years based on patient risk factors.
- Proper shielding – Lead apron with thyroid collar used to block radiation scatter.
- Short exposure time – Entire panorex takes 10-20 seconds for a fast scan.
- Film size – Smaller image receptor held in mouth minimizes irradiation.
- Diagnostic necessity – Panorex taken only if required for diagnosis, not by routine.
Alternative Extraoral X-Rays
Panoramic dental X-rays are only one of the various types of extraoral X-rays that are taken outside the mouth to help find dental issues in the jaw and skull. Alternative extraoral X-rays that your dentist may recommend include:
Tomograms
These blur other layers of the mouth while displaying a specific layer or “slice” of the mouth. This X-ray investigates features that are obscured by other neighboring structures, making them difficult to see properly.
Cephalometric projections
These x-rays make it possible to see a complete side of the head. It examines the teeth in relation to the jaw and the person’s profile. This X-ray is used by orthodontists to create a customized teeth realignment plan for each patient.
Sialogram
This X-ray requires a dye to be injected into the salivary glands so that the glands may be seen on the X-ray film. Because they are soft tissue, salivary glands cannot be seen on an X-ray. Dentists may request this test to check for Sjogren’s syndrome or issues with the salivary glands, such as blockages (a disorder with symptoms including dry mouth and dry eyes; this disorder can play a role in tooth decay).
Dental computed tomography (CT)
This is an imaging technique that visualizes internal structures in three dimensions (three dimensions). Cysts, tumors, and fractures can all be found with this form of imaging on the face’s bony structures.
MRI
This imaging technique provides a 3-D image of the oral cavity, including the jaw and teeth. (This is excellent for assessing soft tissue.)
Cone beam CT
This technique produces 3-D images of dental structures, soft tissue, nerves, and bone. It analyzes cysts and tumors in the mouth and face and aids in guiding the placement of dental implants. Additionally, it can detect issues with the jaws, tooth roots, and gums.
The cone beam CT is different from the traditional dental CT. While the cone beam CT scanner spins once around the patient’s head, collecting all the data, the typical CT scan gathers “flat slices” when the machine rotates the patient’s head multiple times. This approach exposes patients to more radiation.
Cone beam CT has the unique benefit of being applicable in dental offices. Only medical facilities or imaging centers have access to dental computed tomography equipment.
Weighing Benefits vs. Potential Risks
The substantial diagnostic benefits of periodic panoramic X-rays far outweigh the negligible risks from low-level radiation exposure under controlled conditions. Panorex scans provide valuable information for functional and aesthetic dentistry while being safer than many realize.
Final note
While all sources of radiation should be minimized, dental panoramic X-rays remain very low risk with responsible usage protocols. The latest equipment and dosimetry techniques ensure panorex scans are an invaluable diagnostic tool that benefits dental care.
