It is clear that the dental profession has entered a new age of radiographic diagnostic imaging. A number of examples have shown that being able to visualize oral and maxillofacial pathologic entities in three dimensions assists in diagnosing and planning the appropriate treatment. The technology is an improvement for our profession and for the patients it serves.
When pathologic lesions of the jaws are evaluated, a certain amount of information is gathered that is then distilled into the fabrication of a presumptive diagnosis, before surgical intervention (if that is necessary). Demographic information (age, sex, and race) is harvested. Patients are asked if they have certain complaints (pain, altered sensation, or anesthesia), or not. The facial structures are clinically examined for discolorations, depressions, swellings, and asymmetries. Laboratory studies may be indicated and ordered. And then, radiographic tools are used to evaluate that which we cannot see beneath the skin. The exposed images are examined, looking for the lesion’s exact location (maxilla, mandible, anterior, posterior, alveolar process, and so forth). The exact size of the defect and its relative density (radiolucent or radiopaque or a combination) are determined.
Information about potential aggressiveness is sought. Does the lesion expand the cortex? Does it thin it or perforate it? Is it unilocular or multilocular? Is it unifocal or multifocal? What are the characteristics of the border? Is it smooth, ragged, or can one even discern a border. Are teeth involved? Are they impacted or have they been displaced? Have the roots been resorbed? To perfect an accurate diagnosis, these are the questions that must be answered. This will be facilitated by gathering as much information as possible. In general, the greater its quality, the better will be the diagnosis.
Plain film radiography
During the past 4 decades, dentistry has seen a dramatic expansion and refinement of the technology used to identify dental and intraosseous disorders. Whereas the profession had always depended on intraoral radiographs (primarily periapical bite wings and occlusals), during the 1960s, commercially available extraoral panoramic radiography became available for use in the dental office. This introduction allowed the practitioner to gain much more information about the teeth and jaws, especially if surgical intervention was being contemplated. During the next 40 years, the main advances were seen in improvement of film stock and techniques to shorten the time of exposure and thereby the absorbed dose of irradiation. The current advanced state of intraoral and panoramic radiography is highlighted by the replacement of film-based image capture by digital imaging.
During this time frame (and previously as well), when there was a need for more information, patients had to be sent to private or hospital-based medical radiology centers so that more major extraoral facial or skull x-rays could be taken. Examples of films that were routinely ordered are posteroanterior and oblique skull and jaws views, Townes and reverse Townes views, submentovertex and specific exposures of the paranasal sinuses, and tomograms.
With the introduction of tomography, diagnosticians were given an additional tool to evaluate lesions, the ability to look at an object in three dimensions. These films had an advantage over panoramic x-rays since distortion was not as prevalent as is seen in the latter. However, similar to panoramic radiography, the problem of image magnification persisted.