What is a common cause of vertical plane errors on an OPG?

The cause of vertical plane errors on an OPG (Orthopantomogram) is primarily associated with the positioning of the patient's head, particularly if their head is tipped up or down. When the patient’s head is tilted in either direction, it affects the alignment of the x-ray beam with the focal trough where the dental arches are located. This misalignment can lead to distortions in the image, resulting in the teeth appearing elongated or foreshortened.

The OPG requires precise positioning of the patient's head to ensure that the upper and lower jaws are adequately captured in the panoramic view. If the patient's head is tipped upwards, the roots of the teeth may appear shortened, while a downward tilt can cause elongation of the roots on the radiographic image. Therefore, maintaining a neutral position is crucial to avoid vertical plane errors and ensure a clear and accurate diagnostic image.