Panoramic Radiography is the technique used to record or examine both the Maxillary and Mandibular arches along with certain surrounding structures in a single radio graph. As the term Panorama means any wide-angle view or representation, a Panoramic Radiograph helps in getting a wide angle view of both the arches. It is termed as Rotational panoramic radiography or Pantomography. The Panoramic Radiograph is a combination of series of individual images which are combined to form a single Radiograph, The patient is made to stand in the middle of the X-Ray Machine and the X-ray tube head rotates around the head of the patient 360 degrees taking multiple images and a software stitches them together to form a single Radiograph showing the Maxilla, mandible and other supporting structures. Orthopantomogram or OPG is the most commonly used term in clinical practice.
A Panoramic Radiograph measures – Size 5 x 12 inch, 6 x 12 inch.
Uses of Panoramic Radiograph or OPG:
- A single X-ray to study both maxilla and mandible reducing Radiation exposure considerably
- To Visualize Impacted teeth (Impacted third molars or canines) which are not visible due to anatomical limitations in a IOPA
- To access any Mandibular fractures (Body, Symphysis, para symphisis, ramus, condyle, dentoalveolar, condyle) which helps in the treatment plan.
- To check any abnormalities or infections of the Jaw
- To check the extent of any large lesion such as OKC or Dentigerous cyst to help in treatment plan
- To Evaluate TMJ diseases
- To check multiple unerupted supernumerary teeth in both arches seen in certain syndromes such as Gardner’s Syndrome, Cleidocranial Dysostosis, Orofacial Digital Syndrome
- Cases with multiple Caries teeth in both Maxilla and Mandible can be visualized using a single X-ray.
Disadvantages of Panoramic Radiograph or OPG:
- As we can see with any type of Radiograph, even Panoramic Radiograph has its disadvantages.
- Images are not as sharp as Intraoral radiograph, as it is made up of multiple stitched images the sharpness and clarity are reduced
- Due to the reduced sharpness and clarity, it cannot be used to diagnose caries
- It cannot be used to determine interdental bone loss due to the same factors (low sharpness) and also the cahnges in Periodontal ligament are misleading
- In most Panoramic radiographs the anterior segment (mandibular) is either overlapped or blurry and not clear
- There is superimposition in the premolar region
- An Intraoral Radiograph to confirm the findings of a Panoramic Radiograph is required in the Anterior and Pre Molar regions.
Structures Visible in a Panoramic Radiograph or OPG:
- Maxilla – Teeth, alverolar bone
- Mandible – Teeth, alverolar bone
- Infraorbital canal
- Nasal Cavity
- Nasal Septum
- Temporomandibular Joints (TMJ)
- Incisive foramen
- Maxillary Sinus
- Roof of Palate
- Soft palate
- Maxillary Tuberosity
- Pterygopalatine fossa
- Pterygoid process
- Zygomatic bone
- Zygomaticotemporal structure
- Zygomatic Arch
- Coronoid process
- External Ear
- Cervical Vertebrae
- Temporal crest of the mandible
- Mandibular canal
- Oblique line
- Mental foramen
- Dorsum of tongue
- Inferior border of the mandible
- Hyoid bone
- Superimposition of the contralateral jaw
These are the structures which are visible in a Panoramic Radiograph and it helps in determining many larger lesions but if you need minute details such as to differentiate Dental Caries or to check and classify Bone loss, an Intraoral Radiograph is the best.