What happens when two radiographs are taken at different horizontal angles to determine the position of an embedded root?

When two radiographs are taken at different horizontal angles, the movement of the shadow of the embedded root provides significant information about its position relative to the surrounding structures. In this case, the correct answer indicates that the shadow moves in the same direction as the X-ray tube, suggesting that the root is located on the lingual side.

This concept is grounded in the principles of parallax and the relationship between the X-ray beam and the object being imaged. When the tube is angled toward the lingual surface, the shadow of the root will project in that same direction on the radiograph. Therefore, if the shadow moves in tandem with the direction of the tube, it implies that the root is angled towards the back of the mouth (the lingual side), rather than being positioned facially.

Understanding this principle aids in accurately diagnosing the location of embedded roots, which can be crucial for planning treatments such as extractions or surgeries. It can also guide clinicians in making informed decisions regarding the patient's dental health.