Panoramic Radiography Principles Quiz

Panoramic Radiographic Imaging

• Panoramic radiography is a technique that produces a single tomographic image of facial structures, including both maxillary and mandibular arches and their supporting structures.

Principles of Panoramic Radiography

• Scanography: uses a thin moving narrow beam of x-ray to scan a selected part of the object.
• Tomography: allows imaging of one chosen layer or section of the body while blurring images from structures in other planes.

Focal Trough

• A 3D curved zone where the dental arches should be placed, in which structures are clearly demonstrated on a panoramic image.

Indications of Panoramic Radiography

• Assessment of multiple impacted teeth
• Assessment of both jaws before implant placement or planning for dentures
• Demonstrating fractures of the mandible
• Demonstrating pathological lesions as cysts or tumors affecting both jaws
• Demonstrating moderate or periodontal disease in an overall view
• Demonstrating an anterior view of the sinuses and the floor of the nasal cavity
• Orthodontic assessment and evaluation of the eruption patterns, growth, and development of both dentitions

Components of Panoramic Units

• X-ray tube head and slit collimator
• Cassette and cassette-carriage assembly
• Head-positioning apparatus
• Control Panel with exposure controls
• Standing or sitting patient position

Panoramic Technique

• Patient Preparation: explain the procedure, remove metallic objects, and wear a lead apron
• Equipment Preparation: load the panoramic cassette, sterilize the bite-block, and set exposure factors
• Patient Positioning: sit/stand with back straight, position the mid-sagittal plane, and instruct the patient to bite on the plastic bite-block

Advantages of Panoramic Radiography

• Allows examination of both jaws in one radiograph
• Procedures are relatively simple to perform and require minimal time
• Requires minimal patient cooperation
• Can be used with trismus patients (unable to open their mouth)
• Delivers radiation dose less than full mouth periapical survey
• Useful in case presentation and patient education

Limitations of Panoramic Radiography

• Lack of details due to the use of intensifying screen and fast films
• Certain amount of magnification and overlapping is present even with proper technique
• Objects of interest located outside the focal trough are not seen
• High cost of the equipment

Preferential Use of Periapical & Bitewing Radiographs

• Over panoramic radiographs for:
  • Initial (early) caries
  • Initial (early) periodontal disease
  • Early periapical lesion
  • Endodontic treatment

Test your knowledge of the principles involved in panoramic radiography, a technique used to capture tomographic images of facial structures including the maxillary and mandibular arches. Explore concepts such as scanography and tomography.