An OPG (Orthopantomogram) is a wide-view dental X-ray that captures the upper jaw, lower jaw, all teeth, and surrounding structures on a single image. It is one of the most common forms of imaging used in general dentistry, orthodontics, oral surgery, and emergency medicine.
The X-ray is two-dimensional and shows a flattened, half-circle view from ear to ear. Unlike the small intraoral radiographs taken of individual teeth during a routine check-up, an OPG X-ray covers the entire dentition along with the mandible (lower jaw), maxilla (upper jaw), nasal area, and the temporomandibular joint (TMJ), which is the joint connecting the lower jaw to the skull.
When should a patient ask their dentist for a jaw X-ray?
A jaw X-ray is generally recommended when a clinician needs a broader view of the teeth and bones than a routine bitewing or periapical radiograph can provide. Common reasons for referral include persistent jaw pain, swelling, restricted mouth opening, or a clicking sound from the TMJ during chewing.
The X-ray is also frequently requested for the assessment of wisdom teeth (third molars), particularly when impaction is suspected. In children and adolescents, an OPG X-ray may be ordered to monitor the development and eruption pattern of permanent teeth, which is useful before orthodontic treatment or surgical extraction.
Other clinical situations include suspected jaw fractures following trauma, the planning of dental implants, evaluation of cysts or benign tumours within the bone, and the investigation of unexplained facial pain. Patients experiencing chronic headaches or unexplained changes in their bite may also benefit from imaging, as these symptoms can be linked to underlying joint or skeletal issues that are not visible on a standard close-up radiograph.
What is the difference between an OPG X-ray, a CBCT scan, and the smaller X-rays a dentist usually takes?
Dental imaging is divided into two main categories: intraoral and extraoral. Intraoral X-rays are captured with a small sensor placed inside the mouth and include bitewing, periapical, and occlusal views. These provide highly detailed images of individual teeth, the roots, and the surrounding bone, but cover a limited area.
Extraoral X-rays are captured with equipment positioned outside the mouth and include the OPG, the Lat Ceph (Lateral Cephalometric Radiograph), and CBCT (Cone Beam Computed Tomography). An OPG offers a broad two-dimensional overview of the teeth and jaw but trades fine detail for coverage. A Lat Ceph is a side-view X-ray used primarily in orthodontic planning, showing the relationship between the jaw, teeth, and facial bones in profile.
CBCT differs significantly in that it produces a three-dimensional reconstruction of the teeth, jaw, sinuses, and surrounding tissues. CBCT is generally reserved for situations requiring precise spatial information, such as implant placement, complex extractions, or assessment of impacted teeth in close proximity to nerves. The choice of X-ray depends on the clinical question being asked, the level of detail required, and the radiation dose considered appropriate for the patient.
How much does an OPG X-ray cost in Australia, and is it covered by Medicare or private health insurance?
The cost of an OPG X-ray in Australia varies according to the provider, the type of clinic, and whether the patient is referred by a dentist or a medical practitioner. Most private radiology clinics charge between $60 and $150 for a standard OPG X-ray, while in-house dental clinics that bundle the scan with a consultation may offer different pricing structures.
Medicare provides a rebate for OPG imaging under specific Medicare Benefits Schedule (MBS) item numbers, such as item 57960, when the X-ray is requested by a registered medical practitioner for a condition with a clinical indication beyond routine dental review. Imaging requested solely for general dental check-ups or elective orthodontic planning is generally not eligible for a Medicare rebate, as dental services fall outside standard Medicare coverage in Australia.
Private health insurance with dental extras cover may contribute toward the cost of dental X-rays taken in a dental clinic. The level of cover depends on the specific policy, the annual limit, and any waiting periods that may apply. Patients are encouraged to confirm rebate amounts with their fund prior to the appointment and to request a written quote from the imaging provider.
What can a dentist or radiologist actually see in a dental X-ray of the teeth and jaw?
An OPG X-ray provides information about both the teeth and the bones that support them. The number, position, orientation, and developmental stage of all teeth can be assessed, including those that have not yet erupted. This makes the X-ray particularly useful in identifying impacted wisdom teeth, supernumerary (extra) teeth, and abnormalities in the eruption pattern of children.
The X-ray also reveals bone-related conditions such as periodontal bone loss, cysts, benign tumours, and changes associated with infection or trauma. Fractures of the mandible, particularly those involving the body, ramus, or condylar process, are often identifiable on an OPG, although additional views may be required for fractures near the symphysis menti (the front centre of the lower jaw).
The temporomandibular joint can be examined for signs of degeneration, dislocation, or asymmetry. The maxillary sinuses, which sit directly above the upper teeth, are partially visible and may show evidence of sinus disease or thickening of the sinus lining. In some cases, a dental X-ray can also reveal early signs of conditions outside the immediate dental field, including calcifications in the carotid artery and indicators of reduced bone density in the jaw, which may warrant further investigation.
Is the radiation dose from a dental X-ray safe for children, pregnant women, and people having frequent scans?
The radiation dose from an OPG X-ray is considered low. A typical scan delivers approximately 9 to 24 microsieverts (µSv) of effective radiation, which is comparable to the dose received from a few days of natural background radiation, and substantially lower than a standard chest X-ray.
For context, a long-haul flight exposes a passenger to around 30 to 40 µSv due to cosmic radiation, and daily background exposure from soil, building materials, and the atmosphere averages around 8 to 10 µSv. Digital X-ray systems further reduce the dose by up to 80 percent compared to traditional film-based equipment, and most clinics in Australia have transitioned to digital imaging.
Standard radiation protection measures are applied during the procedure, including a lead apron over the chest and a thyroid collar around the neck where appropriate. The principle of ALARA (As Low As Reasonably Achievable) guides the frequency of imaging, meaning X-rays are taken only when the clinical benefit clearly outweighs the radiation exposure.
For children, the dose is adjusted according to age and size, and an OPG X-ray is generally limited to situations where intraoral images are not sufficient or practical. During pregnancy, dental X-rays are usually deferred unless there is a clinical urgency. The Australian Dental Association and the Royal Australian and New Zealand College of Radiologists consider properly shielded dental imaging to pose minimal risk to the developing fetus, but elective scans are typically rescheduled until after delivery as a precautionary measure.
