Concepts of Panoramic Radiography Introduction DHY 202 Clinical Radiology I Dental Hygiene Department William Rainey Harper College

Introduction to Panoramic Radiography Commonplace in dental practice Considered essential in radiographic diagnosis 30% of dental units sold are panoramic

Introduction to Panoramic Radiography “Panorama” means unobstructed view of a region in any direction Panoramic radiograph show greater coverage than periapical and bitewing radiographs

Introduction to Panoramic Radiography New technique Introduced in 1959 Employs scanography (slit beam) & curved surface rotational tomography

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

Indications for Panoramic Pathology-cysts, tumors Trauma-fractures Growth & development Client management Edentulous Localization: anatomy, objects, implant placement Carotid artery condition

Advantages of Panoramic Radiography Field size Quality control Simplicity Time & rapidity of the procedure Client cooperation Dose Minimal infection control Gross anatomy & pathology visible

Disadvantages of Panoramic Radiography Image quality Focal trough limitations Equipment costs Overuse

Disadvantages of Panoramic Radiography Image quality Magnification Distortion Poor definition compared to intraoral Overlap Superimposition & ghost images

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

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 client’s arches image equally well

Disadvantages of Panoramic Radiography Distortion Vertical & horizontal distortion with variations causes uneven magnification

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

Disadvantages of Panoramic Radiography Superimposition & Other Imaging Quirks Ghost images may hide pathosis Soft tissue shadows may mimic pathosis