Concepts of Panoramic Radiography Introduction

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Concepts of Panoramic RadiographyIntroduction

• DHY 202 Clinical Radiology I
• Dental Hygiene Department
• William Rainey Harper College

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Introduction to Panoramic Radiography

• Commonplace in dental practice
• Considered essential in radiographic diagnosis
• 30 of dental units sold are panoramic

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Introduction to Panoramic Radiography

• Panorama means unobstructed view of a region in
  any direction
• Panoramic radiograph show greater coverage than
  periapical and bitewing radiographs

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Introduction to Panoramic Radiography

• New technique
• Introduced in 1959
• Employs scanography (slit beam) curved surface
  rotational tomography

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Client Dose from Panoramic Radiography

• 10 times less radiation than a complete
  intraoral survey using long, round PID E film
• 4 time less radiation than a bitewing survey
  using long, round PID and E film

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Indications for Panoramic

• Pathology-cysts, tumors
• Trauma-fractures
• Growth development
• Client management
• Edentulous
• Localization anatomy, objects, implant placement
• Carotid artery condition

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Advantages of Panoramic Radiography

• Field size
• Quality control
• Simplicity
• Time rapidity of the procedure
• Client cooperation
• Dose
• Minimal infection control
• Gross anatomy pathology visible

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Disadvantages of Panoramic Radiography

• Image quality
• Focal trough limitations
• Equipment costs
• Overuse

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Disadvantages of Panoramic Radiography

• Image quality
• Magnification
• Distortion
• Poor definition compared to intraoral
• Overlap
• Superimposition ghost images

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Disadvantages of Panoramic Radiography

• Poor image quality due to
• Tomographic process
• Increased object-film distance
• Use of intensifying screens
• Faster film with larger crystals

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Disadvantages of Panoramic Radiography

• Focal Trough (Image Layer)
• Areas outside are not visible
• Size shape limits imagery to those structures
  which fit into the image layer
• Size shape not adjustable so not all clients
  arches image equally well

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Disadvantages of Panoramic Radiography

• Distortion
• Vertical horizontal distortion with variations
  causes uneven magnification

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Disadvantages of Panoramic Radiography

• Superimposition Ghost Images
• All objects in the field of the beam, even those
  outside of the image layer are projected onto the
  film but most are not seen.
• Objects with the greatest density are projected
  in two places on the film
• Intended (useable image)
• Ghost image (reversed, higher, blurred)
• Frommer 2001

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Disadvantages of Panoramic Radiography

• Superimposition Other Imaging Quirks
• Ghost images may hide pathosis
• Soft tissue shadows may mimic pathosis