"We now look and are able to see more clearly," said Jack Easley, DVM, MS, Dipl. ABVP, a general practitioner in Shelbyville, Ky., about the use of open-mouth radiographs in the field to understand equine dental problems. In his presentation, "A New Look at Dental Radiology" at the 2002 American Association of Equine Practitioner's (AAEP) Convention, Easley discussed how open-mouth radiographs can be invaluable tools for the equine practitioner in the diagnosis and treatment of all types of dental abnormalities. He believes that radiology has not been used enough in the field by practitioners.

"Open-mouth films bring the upper and lower occlusal (biting/grinding) surfaces out of contact and decrease superimposition (overlay) of the right and left arcades (rows of teeth)," he said. This technique can allow the practitioner to see the entire circumference of the tooth crown, which was previously obscured. With conventional closed-mouth radiographic projections, the erupted crown is obscured by superimposition of the crowns of the opposite dental arcade.

Easley pointed out that differences in tissue density and the increasing width of the horse's head from front to back usually necessitates more than one film of one anatomical area to be taken in order to highlight that area. He also said that coning down (concentrating the beam on one area of the head) on the radiograph allows better contrast and detail over a particular area of concern. He recommends taking radiographs from the right and left sides.

Heavy sedation is necessary for about 20-30 minutes for safety during radiography and to help open the horse's mouth. Sedation allows the horse to be more comfortable and allows the veterinarian to perform a more detailed exam. The horse's head is rested on a table or support stand to help achieve motionless radiographs, which aids in diagnosis