When conducting an OPG, which of the following should be adjusted to avoid horizontal plane errors?

When conducting an Orthopantomogram (OPG), the rotation of the patient's head is crucial for ensuring accurate imaging. This adjustment helps align the patient's dental arches with the focal trough, which is the three-dimensional zone where the dental structures are in sharp focus. If the patient's head is not positioned correctly—either tilted or rotated—this can lead to horizontal plane errors, manifesting as distortion in the image.

By correctly aligning the patient's head so that it is positioned in accordance with the specific guidelines for OPG, dental professionals can capture clear and accurate visual data for diagnostic purposes. This precise positioning is central to avoiding overlapping of teeth and providing a clear representation of the jaw structures.