When viewing a panoramic (PANO) radiograph, what can cause an exaggerated smile effect?

An exaggerated smile effect on a panoramic radiograph occurs when the patient's chin is positioned too low during exposure. This positioning leads to distortion in the image, causing the anterior teeth to appear more pronounced at the incisal edges, which can create that exaggerated smile appearance. When the chin is too low, it alters the angling of the X-ray beam relative to the curvature of the dental arch, which is responsible for this visual distortion. Proper chin placement is critical in achieving a balanced image, and incorrect positioning can significantly affect the interpretation of the radiograph.