Now, a new study by dental researchers at the University at Buffalo has shown that one type of X-ray patients receive routinely, called the panoramic X-ray, could be used selectively in some cases instead of as a routine diagnostic tool.
Results of the study were presented today (March 11, 2005) at the International Association on Dental Research General Session, being held in Baltimore.
"You can't assess cavities or gum disease on a panoramic X-ray," said Lida Radfar, D.D.S., senior author on the study and an assistant professor of oral diagnostic sciences in the UB School of Dental Medicine. "If a small X-ray isn't good enough for a condition you see in a patient, then a panoramic X-ray can be done. But our results show it isn't necessary routinely for every single patient."
As the name implies, panoramic X-rays provide a wide view of the teeth, jaws and surrounding structures and tissues. Patients have a panoramic X-ray taken for an initial evaluation, followed by a series of close-up views of all sections of the teeth, called periapical X-rays. A periapical X-ray gives a close and in-depth look at a particular tooth. A "full-mouth series" consists of a group of periapical X-rays taken of all the patient's teeth.
Nearly everything a dentist needs to know about a person's oral health is revealed by full-mouth periapical X-rays, said Radfar, dispensing with the usefulness of the routine panoramic view.
Radfar and colleagues randomly selected 1,000 panoramic X-rays from records of patients who were admitted to UB dental-school clinics between January 2000 and December 2003. The sample was composed of records from 536 women and 464 men, who had a mean age of 52.
Two dental experts evaluated the X-rays for evidence of bone lesions or other abnormal appearances that would indicate trouble. The evaluators found a total of 352 lesions, and concluded that all but a few would have been picked up by full-mouth-series X-rays.
The only lesions that would not have been picked up on a full-mouth series, said Radfar, were those in the sinus cavities of the cheeks seen in 1.5 percent of the panoramic X-rays; those in the soft tissue of the neck, revealed in 4.8 percent of panoramic X-rays, and three lesions located in the upper portion of the jaw bone close to the temporomandibular jaw joints.
"Based on our study, the panoramic X-ray has limited value," said Radfar. "Eliminating it as a routine part of dental care would expose patients to fewer X-rays, although the amount is minimal, and save costs. And if it isn't necessary, why do it?"
Additional researchers on the study were Nader Ehsani and Lakshmannan Suresh, students in the UB dental school.
The University at Buffalo is a premier research-intensive public university, the largest and most comprehensive campus in the State University of New York.