title: Limitations of the panoramic radiograph's focal trough: a case report.
abstract: This report of a 10-year-old boy illustrates the limitations of the focal trough in panoramic radiography. Because of the patient's large overjet, a supernumerary upper incisor tooth was not visible on a panoramic radiograph. The positioning of the patient within the panoramic machine is critical in obtaining the best possible detail from the radiograph, particularly where there are variations in the anterior occlusal relationship.
authors.forename: P
authors.initials: P
authors.lastname: Fowler
mesh_terms: D002648:Child; D003951:Diagnostic Errors; D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging*; D008297:Male; D011862:Radiography, Panoramic / Q000379:methods*; D014096:Tooth, Supernumerary / Q000000981:diagnostic imaging*