Asymmetric position errors
Enlargement of the right side ramus and zygomatic bone, which are far lingual in the focal plane. A visual left-to-right comparison reveals that the right side of the mandible appears elongated, and the posterior teeth of both mandible and maxilla on this side appear enlarged, and they overlap each other. The furcations of the right mandibular molars exhibit “enamel pearls” due to the overlapping.
If the median saggital plane is not symmetrically positioned before the exposure, and also checked from the dorsal aspect, or if the skull moves horizontally during the exposure, a radiographically nondiagnostic image will be the result, and the radiograph will have to be re-taken.