Panoramic imaging, also called panoramic radiography or orthopantomography (OPG), produces a single tomographic image of the maxillary and mandibular dental arches and their supporting structures. It has several advantages, including broad coverage, low radiation dose, short examination time, and usefulness for patients who cannot open their mouth wide. Panoramic images are useful for evaluating trauma, detecting unerupted third molars, and assessing dental diseases, lesions, tooth development, and TMJ issues. Image quality can be affected by magnification, distortion, and overlapping structures. The diagnostic regions of a panoramic image are the maxillary region, mandibular region, dentoalveolar region,

1. Panoramic Imaging

2. Panoramic Imaging
• It is a technique for producing a single tomographic
image of the facial structures that includes both the
maxillary and mandibular dental arches and their
supporting structures.
Or Pantomography

3. Panoramic Imaging
Or Pantomography

4. Panoramic Imaging
Advantages:
• Broad coverage
• Low patient radiation dose
• Convenience of the examination
• Useful in patients who are unable to open their mouths
• Short time required: 3-4 mins
• Useful visual aid

5. Panoramic Imaging
Indications:
• Evaluation of trauma
• Location of third molars
• Extensive dental or osseous disease
• Known or suspected large lesions
• Tooth development
• Retained teeth or root tips
• TMJ pain
• Study of sinuses
• Developmental anomalies

6. Panoramic Imaging
Disadvantages:
• Magnification, Geometric distortion &
overlapped images.
• Resolution of fine anatomic details of peri-apical
area and periodontal structures is less.
• The spinal cord superimpose the anterior region.
• Common to have overlapped teeth images
especially in premolars.
• Expensive

7. Principles of Panoramic Image Formation
• First described by Numata and independently by Paatero
in the late 1940s
• Movement of the film and objects about 2 fixed centers
of rotation.

8. Principles of Panoramic Image Formation
Movement of the film and objects (A, B, C, and D) about two
fixed centers of rotation. Pb, Lead collimator

9. Principles of Panoramic Image Formation
Movement of the film and x-ray source about one fixed
center of rotation. Pb, Lead collimator

10. Principles of Panoramic Image Formation
Movement of the film and x-ray source about a shifting
center of rotation. Pb, Lead collimator

11. Principles of Panoramic Image Formation
Movement of the x-ray source and beam.

12. Image Layer
• Is a 3-D curved zone, or “focal
trough” where the structures
lying within this layer are
reasonably well defined on final
panoramic image.
• The images seen on the OPG
consists largely of anatomic
structures located within the
focal trough
• Objects out of focal trough are
blurred, magnified, reduced or
distorted.
• The shape of the focal trough
varies with the brand of
equipments used.
Or Focal Trough

13. Image Layer
Factors that affect image layer size:
• Arc path
• Velocity of the receptor and x-ray tube head
• Alignment of the x-ray beam
• Collimator width

14. Image Layer
• Mandible supporting a metal ring positioned at the center of
the focal trough.
• The incisal edges of the mandibular teeth are indexed by a
bite rod-positioning device.
• The Mandible is positioned at the center of the trough.

15. Image Layer
• Ring 5 mm anterior to Focal Trough

16. Image Layer
• Ring 5 mm posterior to Focal Trough

17. Image Layer
• This distortions result from the reciprocal horizontal
movements of the receptor and x-ray source.
• When the mandible is displaced to the lingual side of its
optimal position in the image layer, the beam passes more
slowly through it. The images of the structures are elongated
horizontally thus, appear wider.
• When the mandible is displaced toward the buccal, the beam
passes at a rate faster than normal through the structures,
thus appear thinner.

18. Interpreting the Panoramic Image
The FOUR DiagnosticRegionsin a Panoramic Image:
MaxillaryRegion
MandibularRegionDentoalveolarRegion
TMJ,includingretromaxillary
andcervicalregion

19. Interpreting the Panoramic Image
Maxillary Region:

20. Interpreting the Panoramic Image
Maxillary Region:

21. Interpreting the Panoramic Image
MandibularRegion:

22. Interpreting the Panoramic Image
MandibularRegion:

23. Interpreting the Panoramic Image
DentoalveolarRegion:
• Shape and angulation of roots
• Alveolar bone and periodontium
• Shows gentle curve of occlusal plane
• Missing 3rd molars
• Presence of metallic restorations

24. Interpreting the Panoramic Image
SoftTissueImages:

25. Interpreting the Panoramic Image
SoftTissueImages:

26. Interpreting the Panoramic Image
Airspace:

27. Interpreting the Panoramic Image
Airspace: