Radiographic selection criteria: the need for continued leadership.

Until recently, dental educators placed minimal emphasis on teaching guidelines for the prescription of radiographs. In my predoctoral dental training during the early 1960s, I was taught that patients need a full mouth series at the initial examination and every 5 years thereafter, and that posterior bitewings are needed at 6-month intervals as a component of recall examinations. Since I believed that what was taught in dental school must be correct, I incorporated this approach into my clinical practice for 2 years in the United States Air Force and the initial years of my 10 years as a private general practitioner. As my practice grew and matured, I began to see many negative bitewings at recall and unproductive periapical films in the 'every 5-year' full mouth series. This observation led me to modify my clinical protocol for recall patients by selectively lengthening the interval between bitewings and prescribing less than a full series for new patients with low disease levels. Hence, this subject has been of particular interest to me for three decades. Since becoming a dental educator in 1974, it has been very interesting to observe the approach to the use of radiographs in dental school clinics. Upon my employment at three US dental schools beginning in 1974, 1975 and 1988, I observed that radiographs, usually panoramic, were being made for screening-admission purposes in addition to definitive films taken to complete a diagnosis and treatment plan. This approach resulted in most dentulous adult patients receiving a panoramic radiograph and full mouth series for the initial examination. School protocols for recall bitewings were generally not specified and clinicians used their 'best judgement' when prescribing recall radiographs. Naturally, because this was the approach used in the schools, dental students believed this was the standard care for dental practice. It is safe to say that there are many differing opinions regarding the design of initial and recall radiographic examinations both among dental practitioners and dental school faculty. Surveys of private practices and dental schools have shown this to be true, with wide variations in selection of the types and number of radiographs for initial patients and radiograph intervals used for recall exams. Efforts to develop systematic recommendations for radiographic selection criteria based on scientific evidence began in the early 1970s. Published reports indicated that the use of historical and clinical patient criteria for head trauma victims reduced the number of skull films by 40%. Subsequently, selection criteria were developed by expert panels sponsored by the US Public Health Service (USPHS) for pelvimetry, head trauma victims, and screening and presurgical chest films that have become national standards for the use of these procedures. Similar protocols have been developed in other countries, for instance the UK. Interest in the development and testing of dental radiographic selection criteria was stimulated by a National Conference on Radiographic Referral Criteria for X-Ray Examinations in 1978 sponsored by the US Department of Health, Education and Welfare. Conference recommendations stated that expert panels on radiographic selection criteria should be formed to develop criteria for the use of medical and dental radiographs. In 1983, the USPHS convened a dental panel to study the use of X-rays in dentistry. The Dental Panel met over a 5-year period and published guidelines for prescription of radiographs for general dentistry patients. The report describes background research on efficacy of dental radiographs, effectiveness of the use of patient indicators for selecting radiographic examinations, a protocol for prescribing X-rays for new and recall general dentistry patients and rationale statements for elements of the protocol. Its publication was an important step towards standardization of radiograph prescription in dentistry, and subsequently these recommendations were adopted by the American Dental Association and other dental professional groups. The next phase of work is to gain implementation of the guidelines in dental schools and clinical practices. Although the guidelines have been disseminated widely to schools and dentists, their impact on clinical practice is unknown at the present time. Also, as with any new clinical protocol, continued research to assess the efficacy of the radiology guidelines is needed to confirm and refine the appropriateness of types of radiographs recommended and recall radiograph schedules.