Diagnostic Criteria

The diagnostic criteria for a panoramic image are outlined in Table 4.

An optimal panoramic radiograph should be free from errors related to patient preparation, technique, or exposure.

Figure 21. Optimal Panoramic Image.

Figure 21. Optimal Panoramic Image.

In reality, most panoramic images are not optimal nor ideal but rather present with minor yet acceptable error(s) that do not interfere with diagnosis and treatment planning. In such instances, a retake is not justified.

Figure 22. Panoramic Image with Minor Errors.

Figure 22. Panoramic Image with Minor Errors.

This panoramic image demonstrates a slight downward tilt of the patient’s head evidenced by a minor grin of the occlusal plane, slight foreshortening of the mandibular incisor teeth. In addition, the tongue was not placed against the palate. However, these minor errors do not interfere with the overall diagnostic acceptability of the image.

Figure 23. Panoramic Image with Minor Errors

Figure 23. Panoramic Image with Minor Errors

This panoramic image demonstrates a slight upward tilt of the patient’s head evidenced by a flat occlusal plane, slight elongation of the maxillary incisor teeth, and minor superimposition of the hard palate over some of the maxillary teeth apices. However, these minor errors do not interfere with the overall diagnostic acceptability of the image.

However, there are certain specific critical errors that result in images that fail to fulfill the criteria for an acceptable panoramic image. These errors are critical because they usually necessitate re-exposure of the patient.

The principle technical criterion for acceptance of a panoramic radiographic image is that it should capture all the structures of the maxillofacial region. If any of the structures are not present, either because they are not covered or obscured, then a retake is indicated. It should be remembered that the patient pays for the interpretation and subsequent diagnosis generated from the panoramic image and not the procedure itself.

Specific exclusionary criteria include the inability to visualize any of the following either due to the structure not being imaged on the receptor or obstruction of the structure from view:

• Condyle of the temporomandibular joint (TMJ)

• Mandibular/maxillary anterior region

• Mandibular ramus

Figure 24 demonstrates three of the most common reasons for retakes; neither condyle of the TMJ, the mandibular anterior region nor the mandibular ramus are visualized on this radiographic image. In this particular case it is because the patient’s head is tilted too far down during exposure.

Figure 24. Unacceptable Panoramic Image

Figure 24. Unacceptable Panoramic Image

Figure 25 demonstrates three further reasons for retakes: poor visualization of the maxillary anterior region, inadequate coverage of structures due to the presence of ghost images and/or labels. In this particular case the patient is positioned too far backward and has their head tilted too far up (as evidenced by the reverse or frown occlusal plane). These positioning errors place the maxillary anterior region out of the focal trough and produces excessive ghosting of the amalgam restorations of the opposite side.

Figure 25. Unacceptable Panoramic Image

Figure 25. Unacceptable Panoramic Image